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Policha, Tobias. "Pollination Biology of the Mushroom-Mimicking Orchid Genus Dracula." Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/18404.
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Dracula orchids are hypothesized to rely on mushroom mimicry for pollination. These orchids look and smell like mushrooms and are pollinated by mushroom-associated flies in the family Drosophilidae. Dracula includes over 130 species, representing a significant radiation, yet there has never been a systematic study of their pollination biology. Elucidating the processes and mechanisms of pollination in these flowers will broaden our understanding of mimicry within the Orchidaceae, a family well known for its diverse pollination strategies, as well as add to the growing literature on the evolution and maintenance of communication signals. In this study we demonstrate the co-occurrence of the mimics and the putative mushroom models, which is important for evolution by natural selection. We also showed that the resemblance to mushrooms is in fact adaptive, a requisite for floral mimicry. We did this by determining that insect visitors are required for pollination and subsequent fruit set with a hand pollination experiment. We also measured increased visitation rates to the orchids when adjacent to mushrooms.
The mechanisms whereby plants attract pollinators can be diverse and often multi-modal, particularly in deceptive systems. Dracula orchids are no exception, with both visual and olfactory signals contributing to the overall success in attracting visitors. We used a series of experiments, first selectively masking the visual and olfactory cues successively, and then using 3D-printed artificial flowers to further disentangle these cues and determine their effect in combination. Upon confirmation that both play a role, we dissected each aspect further. We utilized the artificial flowers to determine the roles of color, contrast, and pattern and employed gas chromatography-mass spectroscopy to identify the volatile signals. The results show that fine-scale contrast is critical to the visual component and that these flowers produce the volatile `mushroom-alcohol' (1-octen-3-ol) in their labella.
Finally, we specifically address the hypothesis of brood-site mimicry by using a combination of field observations, insect collections, and rearing studies. The flies gain shelter, a rendezvous location, and food from the flowers. However, no mushroom visiting flies hatched from the flowers, suggesting this may be a brood-site mimicry.
This dissertation includes previously unpublished co-authored material.2015-09-29
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Wolff, Doris Anne. "Pollination biology of gentianales in a southern Ecuadorian montane forest." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979001625.
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Bonner, Lynda J. "Pollination biology of Lycopersicon esculentum Mill. in summer and winter." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327822.
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Levin, Rachel Ann. "Relationships among fragrance, phylogeny and pollination in southwestern Nyctaginaceae." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280128.
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Fragrances appear to act in conjunction with visual cues to attract specific pollinators. Besides the ecological influence of pollinator type on fragrance, as with many other attributes of organisms, phylogenetic history may also affect fragrance composition. In this dissertation I examine the quality and quantity of floral and vegetative fragrance, and explore the relationships among fragrance, pollinators, and phylogenetic history in the plant family Nyctaginaceae. Using DNA sequence data, I inferred phylogenetic relationships among and within the Nyctaginaceae genera Acleisanthes, Selinocarpus, and Mirabilis. There is a high incidence of hawkmoth pollination within these genera, in addition to multiple pollinator transitions. Results suggest that neither Acleisanthes nor Selinocarpus are monophyletic, but that together they comprise a monophyletic lineage. Because of this finding, I have taxonomically combined these two genera into a single genus. Analyses of floral and vegetative fragrance from Acleisanthes, Selinocarpus, and Mirabilis species included in the phylogenetic study show that each species has a unique fragrance profile. Further, although there is substantial variation among individuals within species, intraspecific variation is significantly lower than interspecific variation in fragrance profiles. Fragrances are composed of 5--108 different compounds from at least seven different biosynthetic classes. Some species produce most of their fragrance vegetatively, while floral emissions are the sole source of volatiles in other taxa. Results show that neither total amount of volatiles nor the amount of floral volatiles per mug floral tissue is correlated with pollinator type. However, the emission of nitrogen-bearing compounds appears to have been lost in those lineages that have also lost moth pollination, suggesting that the presence of nitrogen-bearing compounds may be important for moth attraction. Although the phylogenetic signal in the fragrance data is not entirely congruent with the signal in the DNA sequence data, certain compounds and biosynthetic pathways do support the independent phylogeny inferred using the DNA data. However, it is also clear that many compounds are highly homoplastic, yielding limited phylogenetic information. Overall results suggest that phylogenetic relationships rather than pollinator affinities are better predictors of fragrance composition among these Nyctaginaceae species.
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Halgryn, Petrus J. (Petrus Johannes). "Cross pollination biology of apples, with special reference to 'African Red'." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51667.
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Thesis (MScAgric)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: Ineffective pollination of the main cultivar with the pollinator cultivar is due to either an incompatibility problem between the main and pollinator cultivar, or because the flowering times of the main and pollinator cultivars do not overlap adequately. Three trials were conducted to try and find a more effective way to determine cultivar compatibility and to group cultivars together according to their budburst reaction to chilling. Most apple cultivars are self-incompatible and need cross-pollination for fruit set. Due to differences in the genetically defined fertilisation compatibility between the pollen from the male parent (pollinator) and the egg cell of the female parent, various apple pollinators differ in their ability to set fruit with viable seed. Fruit weight and size are positively correlated with seed set although it has been found that the pollinator can have a direct influence on fruit quality. 'African Red' apple trees on M7 rootstock in an evaluation block on a commercial farm in the Koue Bokkeveld region (32°55'N 19°27'E, Mediterranean climate, ;::::1060Utah chill units, and ;::::530mm rainfall annually; altitude 966 m) were used to assess the influence of 5 pollinators ('Granny Smith', 'Winter Banana', 'Cripps' Pink', 'Cripps' Red' and 'Simpson Crab') on fruit set, fruit weight and length and diameter. The degree to which 'African Red' is self-compatible was also assessed and the effect of flowering position ("king" vs. lateral) on fruit quality was determined. None of the pollinators showed a significantly higher fruit set. No differences in fruit set were found between the "king" and lateral flowering positions. No significant differences were found in the average number or weight of well developed seeds between pollinators. In both years fruit weight was significantly correlated to seed number for all five pollinator cultivars. In 1998 'Simpson crab' gave fruit that were significantly more elongated than those of 'Cripps' Pink'. 'African Red' is highly self incompatible. Compatibility assessments that are based on the number of fruit that develop after the flowers ofthe main cultivar had been hand pollinated in field trials are a time-consuming process. Allele-specific PCR amplification for some of the known S-alleles of the incompatibility S-gene (S2, S3, S5, S7 and S9) was carried out to successfully predict the compatibility of genotypes. The results compared well with that found in literature. For all the Malus domestica cultivars tested at least one, but in some instances both alleles of the S-gene were determined. 'Simpson crab' (Malus baccata) did, however, not possess any of the tested S-alleles. One-year-old, ca. 40 mm long shoots of various apple cultivars were selected from commercial orchards in both the Elgin [34°S, 305 m, ca. 750 chill units (CU) (Richardson et al., 1974)] and Koue Bokkeveld (33°S, 945 m, ca. 1300 CU) regions of the Western Cape, South Africa in two consecutive years (1998 and 1999). Shoots were forced at a constant 25°C with continuous illumination after receiving their allocated chill units. The effect of chilling period on the budburst of each cultivar in both regions was estimated by determining, 1) the total proportion of budburst (%Bb), 2) the proportion of shoots with terminal budburst (%TBb), and 3) the rate of budburst [lI(days to 25% budburst)]. It was found that these indices differed significantly between cultivars, and within cultivars between areas, as far as budburst patterns, in reaction to chilling, were concerned. The rate of budburst was the most consistent in describing the reaction of buds to different chilling periods and could be used to group cultivars together according to their budburst reaction to chilling.
AFRIKAANSE OPSOMMING: KRUISBESTUIWINGSBIOLOGIE VAN APPELS MET SPESIALE VERWYSING NA 'AFRICAN RED'. Oneffektiewe kruisbestuiwing III die boord kan toegeskryf word aan Of onverenigbaarheid tussen die hoof- en bestuiwingskultivar Of as gevolg van die blomtyd van die kruisbestuiwer wat nie genoegsaam oorvleuel met die van die hoofkultivar nie. Drie proewe is uitgevoer om 'n meer effektiewe proses daar te stel vir die toets van kultivarverenigbaarheid en om kultivars te probeer groepeer na gelang van hul reaksie op bepaalde hoeveelhede koue. Meeste appelkultivars is selfonverenigbaar en benodig kruisbestuiwing vir genoegsame vrugset. As gevolg van verskille III die geneties gedefinieerde bevrugtingsverenigbaarheid tussen die stuifmeel van die manlike ouer (bestuiwer) en die eiersel van die vroulike ouer (hoofkultivar), verskil bestuiwers in hul vermoë om vrugte met sade te set. Vruggrootte en -massa is positief gekorreleerd met saadset alhoewel dit al gevind is dat die bestuiwer op sig self ook 'n invloed op vrugkwaliteit kan hê. 'African Red' appelbome op M7 onderstamme, in 'n evaluasie blok op 'n kommersiële plaas in die Koue Bokkeveld (32°55'N 19°27'E, Meditereense klimaat, ::::1060 Utah koue eenhede, en ::::530mmjaarlikse reënval; ligging 966 m), is gebruik om die invloed van 5 bestuiwers ('Granny Smith', 'Winter Banana', 'Cripps' Pink', 'Cripps' Red' and 'Simpson Crab') op vrugset, vrugmassa, -lengte en -deursnee oor twee seisoene te bepaal. Die mate waartoe 'African Red' self onverenigbaar is en die effek van blomposisie ("king" vs laterale blom) op vrugkwaliteit is ook bepaal. Geen een van die bestuiwers het vrugset beduidend beïnvloed nie. Ook is daar geen verskille gevind tussen die "king" en laterale blomposisies t.o.v. vrugset nie. Geen beduidende verskille is tussen bestuiwers gevind in die gemiddelde aantal of gewig van volsade geset nie .. In albei jare was die vrugmassa beduidend gekorreleerd met saadset vir al vyf bestuiwerkultivars. In 1998 het 'Simpson Crab' vrugte geset wat beduidend langer was as vrugte wat geset het toe 'Cripps' Pink' as bestuiwer gebruik is. Daar is ook gevind dat 'African Red' hoogs selfonverenigbaar is. Verenigbaarheidstoetse wat gebaseer is op die aantal vruggles wat ontwikkel nadat blomme van die hoofkultivar met die hand bestuif is, is 'n tydsame proses. Allele spesifieke PCR amplifikasie vir bekende S-allele van die onverenigbaarheids S-geen (S2, S3, S5 S7en S9) is suksesvol uitgevoer om die verenigbaarheid van genotipes vooraf te bepaal. Die resultate het goed vergelyk met wat in literatuur gevind is. Vir al die Malus domestica spesies wat getoets is, is ten minste een, en in sommige gevalle twee, van die S-allele gevind. Die blomappel 'Simpson' (Malus baccata) het egter nie een van die vyf S-allele opgelewer nie Een-jaar-oue, 40 mm lang lote van verskeie appelkultivars, is in twee opeenvolgende jare (1998 en 1999) vanuit kommersiële boorde in beide die Elgin [34°S, 305 m, ca. 750 koue eenhede (CU) (Richardson et al., 1974)] and Koue Bokkeveld (33°S, 945 m, ca. 1300 CU) areas van die Wes Kaap gsny. Die lote is geforseer om te bot by 'n konstante temperatuur van 25°C met deurlopende beligting, nadat elke groep lote aan 'n bepaalde hoeveelheid koue blootgestel is. Die effek van koue op bot van elke kultivar in beide areas is bepaal deur, 1) die totale persentasie knoppe wat gebot het, 2) die persentasie terminale knoppe wat gebot het, en 3) die tempo van bot [l/(dae tot 25% bot)] te meet. Daar is gevind dat bo-genoemde parameters beduidend tussen kultivars, en binne kultivars tussen areas, verskil. As 'n beskrywing van die reaksie van knoppe op koue het die tempo van bot die mees konstante resultate oor die twee opeenvolgende seisoene gelewer en kon hierdie parameter gebruik word om kultivars in groepe, na gelang van hul reaksie op koue, in te deel.
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Huda, Mohammed Kamrul. "Diversity, ecology, reproductive biology and conservation of orchids of south east Bangladesh." Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327403.
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Keys, Roy Nelson. "Mating systems and pollination biology of velvet mesquite (Prosopis velutina Wooten)." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186195.
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Little is known of the genetics of multipurpose trees in the genus Prosopis. These studies, which examined mating systems and pollination biology of P. velutina Wooten, improved our understanding of genetic structure and gene flow in natural and artificial populations. There was no evidence for either male or female sterility, but early and later flowering trees could be functionally male and female, respectively. Pollen loads on stigmas of mature flowers were adequate for pod production, so low fruit:flower ratios in P. velutina were not attributed to inadequate pollination. Flowers were receptive to pollen prior to complete anthesis when only stigmas were exserted, a trait that will facilitate controlled pollination. Hand pollinations demonstrated that P. velutina was self-fertile. Lower pod production in selfs compared to outcrosses was attributed to genetic load. Multilocus estimates of mating systems parameters derived from data for 3 isozyme systems of 30 open-pollinated families revealed 20.7% selfing and 7.1% biparental inbreeding in mating in three natural populations. Implications of self-fertility and inbreeding were discussed in relation to breeding programs, and natural and artificial populations. Genetic subdivision was found within these populations, but not among them. This genetic structure was attributed to initial long-distance seed dispersal into grasslands by livestock, followed by short-distance seed dispersal from "nucleus" trees by livestock and wildlife. Twenty-six genera of insects foraged on the flowers. Small insects were effective pollinators of P. velutina, but nocturnal insects were not. The most efficient pollinators, based on pod production after single visits to inflorescences, were native leafcutter bees (Megachilidae), followed by Perdita spp., Apis mellifera, and Volucella spp. Insect behavior can affect plant mating systems by altering the relative amounts of selfing and outcrossing, and as pollinator guilds change through the flowering season. It was also found that individual trees can bear up to three cohorts of flowers during a growing season. These factors combine to make the mating systems of P. velutina more complicated than previously thought. Approaches for using insects in breeding and seed orchards were discussed.
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Boyd, Amy Elizabeth. "Evolution of floral traits: Biogeography, pollination biology and phylogenetics in Macromeria viridiflora." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279781.
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Macromeria viridiflora is an herbaceous perennial in which floral traits vary geographically. In my dissertation research, I analyzed geographic variation in plant morphology and pollinator assemblages. I conducted experiments to determine the breeding system of the plants, and used visitation rate and pollen deposition to compare effectiveness of floral visitors as pollinators. I analyzed aspects of pollinator attractants and rewards in the flowers and placed this into the context of pollinator syndromes. In addition, I used phylogenetic analysis of the genus to determine polarity of change in corolla size within the species. Analysis of morphometric data from eight sites across the range of the species revealed significant among-population variation in vegetative and floral traits. Flower size variation is particularly strong and follows a latitudinal cline. Hawkmoths and hummingbirds were the main floral visitors throughout the range. The large-bodied hummingbirds visiting plants in the southern regions are not present in the northern regions, where flowers are visited by hummingbirds with barely half the body size and much shorter bills. This difference in bill size of hummingbird pollinators mirrors the geographic variation in flower size in M. viridiflora, suggesting that pollinator-mediated selection may be acting upon the species. Flowers of M. viridiflora have several characteristics that fit both the hummingbird and hawkmoth pollinator syndromes, namely copious sucrose-rich nectar and long floral tubes. However, they also have characteristics that correspond with a single major pollinator. This plant therefore presents a compromise floral syndrome that attracts two classes of pollinators. Breeding system studies showed that whereas plants are self-compatible and occasionally produce seed autogamously, pollinators are important for reproductive success in the plants. Combining visitation rate and pollen deposition as measures of pollinator effectiveness, hummingbirds were found to be the most effective pollinators at both sites. Phylogenetic analysis produced a single most parsimonious tree that supports the monophyly of the genus. Mapping of corolla size onto the phylogeny indicates that floral size has changed many times within the genus, and that very large corolla size in southern populations of Macromeria viridiflora has been derived from a smaller-flowered ancestor.
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Oliveira, Paulo Eugenio A. M. de. "The pollination and reproductive biology of a cerrado woody community in Brazil." Thesis, University of St Andrews, 1992. http://hdl.handle.net/10023/4657.
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The pollination biology and reproduction of a woody plant community of cerrado, the neotropical savanna vegetation in Brazil, was studied. A delimited area of relatively dense cerrado which included 59 woody species was studied from July 1988 to September 1989 in the Ecological Reserve area of Brasilia Botanic Garden. Aspects of the phenology, floral biology, breeding systems and fruit-set patterns were studied for the whole community or for a subsample of the species in the area. Some species, group of species or aspects of the reproductive biology of these plants were further analyzed in separate case history studies. The species in the community showed varied phenological behaviour with vegetative growth and reproduction distributed throughout the year. It seems that the phenology of adult individuals is, to a certain extent, independent of the markedly seasonal wet and dry climate of the area. Only the seedling establishment seems to be confined to a specific period at the beginning of the rains. Wind and animal dispersal mechanisms are partially constrained showing two different peaks but flowering phenology seems to be much more flexible and even for congeneric species flowering periods may differ markedly. The phenological strategy of each species seems to be a more or less independent assemblage of the possible options in each phenophase. The plants could be grouped in seven pollination guilds based on their main pollinators. These guilds were basically similar to the ones described for other tropical communities. Unspecialized flowers pollinated by small insects, including flies, wasps and small bees formed the most Common group. The more conspicuous and specialized flowers pollinated by medium to large, long-tongued bees formed the second most important group. Other characteristically tropical pollination systems such as bat and beetle pollination were also present. Hummingbird pollination was rare and wind and butterfly pollinated flowers were absent. The fauna of visitors, their foraging habits and possibly their seasonal segregation is similar to that described for Costa Rican seasonal forests, particularly in the case of the large bee fauna. No pollination system seems to be seasonally limited although a peak of large bee pollinated flowers, for example, could be identified at the onset of the rains. Breeding systems could be established for a sample of 22 species with different pollination systems, the majority (86%) of which presented self-incompatibility mechanisms. This sample and the frequency of dioecious species (15% of the total) permitted an estimate of 84% as the frequency of obligatory outcrossing species in the area. Such frequency is similar to those obtained for other lowland tropical forest communities and much higher than the estimates for altitudinal cloud forests in the tropics. Apomixis was present in two species in the community and is possibly present in another two, which indicate that, although rare, this may be an important phenomenon amongst the cerrado woody species. The site of the incompatibility reaction was studied for most of the self-incompatible species and a majority presented "lateacting self-incompatibility", with self-pollen tubes reaching the ovary or even penetrating the ovule. More "classical" self-pollen tube arrest in the style was also observed for some groups. Fruit-set was usually low but the data should be regarded with caution since they varied both spatially and temporally. Nevertheless, some differences between pollination system groups and relationships with breeding system are suggested by the results. The case history studies involved a self-incompatible shrub species, Yellozia squamata (Velloziaceae), which presented a distinct flowering phenology; a bat-pollinated tree, Hymenaea stigonocarpa (Leg. Caesalpinioideae), which presented 'late acting self-incompatibility'; another legume tree, Sclerolobium paniculatum, which present two varieties segregated ecologically but which were not clearly isolated reproductively; contrasting breeding systems, self-incompatibility and apomixis, in two cerrado Eriotheca spp. (Bombacaceae); six species of Vochysia (Vochysiaceae) which occur in different vegetation physiognomies in the Ecological Reserve of the Brasilia Botanic Garden but have very similar floral biology and outbreeding system; a study on some small "settling" moth pollinated species in the study area which have similar outbreeding systems as their large hawkmoth pollinated counterpart; and a general study on the occurrence of dioecy which is less important in cerrado areas than in the contiguous forest habitats. The breeding features emerging from this study support the idea of the cerrado vegetation as stable communities where biomass output is possibly limited by availability of nutrients and restrict establishment conditions, but not restricted by seasonality or disturbance in terms of opportunity and predictability for the reproductive process of the woody plants. If outbreeding systems are indicative of environmental stability, then cerrado conditions seems to be comparable to those in the lowland tropical forest.
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White, David C. J. "Maintaining deception in a rewarding landscape; the pollination biology of deceptive orchids." Thesis, University of East Anglia, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527630.
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Teichert, Holger. "Pollination biology of cantharophilous and melittophilous Annonaceae and Cyclanthaceae in French Guiana." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-63809.
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Bobiwash, Kyle. "Pollination ecology of lowbush blueberry (Vaccinium angustifolium) - The role of introduced pollinator communities, self-fertilization and somatic mutations on fruit set response." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114589.
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This thesis examines fruit yield variation and its causes in the lowbush blueberry (Vaccinium angustifolium). I found that yields exhibits significant variability in fruit within and between fields. An experiment involving controlled introductions of the three pollinator species commonly used in blueberry production—the honeybee (Apis mellifera), the bumblebee (Bombus spp.) and leafcutter bee (Megachile rotundata)—was also conducted. Increasing the abundance or diversity of the introduced pollinator community did not systematically increase fruit set across the experimental populations. There is weak evidence to suggest the combination of bumblebee and leafcutter bee may be more effective at increasing fruit yield than honeybee alone. The behaviour of introduced pollinator species differed between fields depending on the combination of pollinator species present, however, none of these changes was correlated with increased fruit set. As part of this work, self-pollinations and cross-pollinations were conducted in a large number of clones and variation in inbreeding depression of yield was detected among clones. To evaluate whether differences in accumulated deleterious mutations among clones were responsible for variation in inbreeding depression, a follow-up experiment manipulating access to self pollen was undertaken. In addition, differential genetic load was measured, using clone size as a proxy for somatic cell division. Neither clonal size nor self pollen access sufficiently explained the interclonal variation in self fruit set. Within the same fields, geitonogamously-pollinated fruit set was greater than autogamously-pollinated fruit set. These differences suggest the presence of somatic mutations, cell lineage selection, mitotic recombination, or epigenetic changes within lowbush blueberry clones, and they mirror results from studies of several perennial plant species that have revealed autogamy depression to be a significant factor in plant fertility. These results suggest that self-fertilization is an important element limiting fruit set that should be addressed in attempts to increase lowbush blueberry yield.Ce thèse explore la variance du rendement de fruit et les causes des différences dans le rendement vue dans l'espèce de bleuet Vaccinium angustifolium. J'ai trouvé qu'il existe une variabilité dans le rendement de fruit entre les champs et entre les individus du champs. Une expérience visant l'introduction des trois espèces pollinisateur utilisé le plus fréquement (Apis mellifera, Bombus spp., Megachile rotundata) au Nouveau-Brunswick a aussi eu lieu. Lors de l'augmentation de la diversité ou l'abondance il n'y avait aucun gain conséquent dans le rendement de fruit. Il y a un faible temoignage qui suggère que le rendement de fruit est plus élevé dans les champs qui inclut la combinaison pollinisateur de Bombus et Megachile comparé au champs seulement avec Apis introduit. Les mesures de comportement des pollinisateur introduit ont aussi varié entre les champs dépendant des espèces présent dans les champs, mais ces changements en comportement n'ont pas été lié au différences dans le rendement de fruit. Comme partie de cette recherche, des auto- pollinisations et des pollinisations croisée ont eu lieu dans plusieurs clones, avec une variabilité dans la dépression de consanguinité vue entre individus. Pour evaluer si des différences dans l'accumulation des mutations somatiques entre individus sont responsable pour la variabilité dans la dépression de consanguinité, une expérience qui a but de modifié accès de auto pollen a suivie. Pour mésurer la différence en charge génétique, la taille des clones a été utilisé pour représenter la division cellulaire somatique. Ni la taille des clones ou l'accès à l'auto pollen fut capable d'expliquer la variation de rendement de fruit entre les clones. Ces mêmes champs on aussi produit un taux de rendement de fruit plus élevé dans les fleurs fécondé avec le pollen geitonogamous comparé au fleurs fécondé avec le pollen autogame. Ces différences suggèrent la présence des mutations somatiques, la sélection lignée cellulaire, la recombinaison mitotique, ou des changement épigénétique dans les clones de bleuets, et ces résulats reflète d'autres études des espèces de plantes vivaces qui indique que la dépression autogame est une force significative dans la fertilié des plantes. Nos résultats suggèrent que l'auto pollinisation joue un rôle important dans la limitation du rendement de fruit et dois être considéré lorsqu'on essai d'augmenter le rendement de fruit chez le bleuet V. angustifolium.
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El-Sawa, Sherine. "Pollination and breeding of jackfruit (Artocarpus heterophyllus lam.) in South Florida." FIU Digital Commons, 1998. http://digitalcommons.fiu.edu/etd/3129.
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Jackfruit (Artocarpus heterophyllus Lam.) is a multi-purpose fruit tree, native to tropical Asia. It was introduced to South Florida in the early 1900s but has had little commercial importance. In recent years, there has been an increased interest in jackfruit as a commercial crop in South Florida, but there has been little scientific investigation conducted. The pollination mechanism was not clearly understood. This study focused on jackfruit breeding using 'Dang Rasimi' and 'Cheena' cultivars. Controlled hand-pollinations revealed that both cultivars were not apomictic. Both cultivars set fruit with self-pollination, but seed set and many fruit characters such as size, flesh percentage and edible percentage were greatly enhanced with cross-pollination. I conclude that jackfruit are outbreeding plants. Tests for pollen dispersal by wind were inconclusive. A variety of insects were collected, but few had a role in pollination. My results suggest that jackfruit are likely to have insect-assisted wind pollination in South Florida.
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Bolinder, Kristina. "Pollen and pollination in Ephedra (Gnetales)." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-140771.
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Ephedra (Gnetales) is a gymnosperm genus with a long evolutionary history; the first dispersed pollen grains with affinity to the group are known already from the Permian. This thesis focuses on the evolutionary history of the group and different aspects of its pollination mechanisms. Despite the limited number of extant species of the genus (50-60), and a low morphological and genetic divergence among species, there is variation in pollination syndrome in the genus. The prevailing state in Ephedra, and most gymnosperms, is wind pollination. It is therefore surprising that one species, E. foeminea, is insect-pollinated. Together with co-workers I documented the pollination syndromes of E. foeminea and a sympatric species, E. distachya, based on long term field experiments in north-eastern Greece and aerodynamic investigations and calculations. Placing the results into an evolutionary framework reveals that the insect-pollinated species E. foeminea is sister to the remaining (mostly wind-pollinated) genus, and indicates that insect pollination is the ancestral state in the Gnetales. During the course of evolution of the group there has been a shift to wind pollination, which may have played a crucial role for the diversification of the crown group in the Paleogene. Pollination biology is often correlated with the morphology of the pollen such that pollen grains of anemophilous plants are small with a smooth surface, whereas pollen grains of entomophilous plants are larger with an ornamented surface and a covering of pollenkitt. The pollen morphology of Ephedra can be broadly divided into two types: an ancestral type with an unbranched pseudosulcus between each pair of plicae, and a derived type with a branched pseudosulcus between each pair of plicae. Further, the pollen morphology and ultrastructure of the pollen wall in Ephedra are to some degree correlated with the pollination syndrome and capability of long distance dispersal. Pollen of E. foeminea has a denser ultrastructure, as a result a higher settling velocity and is therefore capable of flying shorter distances than does pollen of the anemophilous E. distachya, and other investigated anemophilous species that show a more spacious ultrastructure of the pollen grain. These results can be useful in the reconstruction of the pollination mechanism of extinct taxa of the Ephedra-lineage in the future.
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Teixeira-Martins, Kyle. "Pollination services are mediated by bee functional diversity and landscape context." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121418.
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Wild bees, which exhibit multiple functional traits enabling pollination of apples (Malus domestica Borkh), potentially can compensate for recent declines in domesticated honey bees (Apis mellifera Linnaeus) that are conventionally employed to ensure apple fruit and seed set. Whether compensation is possible will depend on functional diversity in the wild bee community and on the distribution of habitat and resources within the landscape surrounding an orchard that affect wild bee abundance. We studied pollination services and bee functional diversity in 20 apple orchards in southern Quebec, Canada. We evaluated pollinator efficacy by studying: apple visitation rates, approach (front or side-working), body size, foraging type (pollen or nectar foraging), sociality, temporal and climatic activity patterns, and pollen carrying habit. Pollination services were measured as apple fruit set and seed set. A distance-based measure of functional diversity, calibrated with bee traits and weighted by relative abundances in the wild bee community, was used to model pollination services. We correlated the landscape composition and configuration of surrounding natural (forest) and semi-natural (meadow) habitats with bee diversity and pollination services. The incidence of fruit set and seed set in orchards increased with bee functional diversity. Complementarity between managed versus unmanaged bees in traits associated with foraging and resource use drove this relationship. Seed set was also negatively correlated with both the mean distance from surrounding meadows and the total area of surrounding orchards. Bee functional diversity was positively associated with surrounding meadow and forest area. These two land classes complement each other in their seasonal provision of foraging resources for bees. Our models can be used to prescribe management and conservation objectives for meadow and forest habitats that promote bee functional diversity and in turn pollination services. We identify useful wild bee pollinators and discuss their needs in terms of landscape composition and configuration.Les abeilles sauvages, qui possèdent plusieurs caractéristiques fonctionnelles contribuant à la pollinisation des pommiers (Malus domestica Borkh), ont le potentiel de compenser le déclin d'abeilles mellifères (Apis mellifera Linnaeus) qui sont normalement adoptées pour assurer la grenaison et la nouaison des fruits. Les facteurs qui rendront possible cette dite compensation dépendent de la diversité fonctionnelle de la communauté des abeilles sauvages, ainsi que de la répartition de leur habitat au sein du vaste paysage qui entoure les vergers. Nous avons étudié les services écosystémiques et la diversité fonctionnelle des abeilles dans vingt vergers situés au sud du Québec. Nous avons ensuite évalué l'efficacité des abeilles pollinisatrices en étudiant les paramètres suivants : la vitesse de butinage, la fréquence des contacts avec les stigmates, la taille des abeilles, le type de récolte (pollen ou nectar), la sociabilité, le seuil d'activité en fonction des paramètres climatiques et temporaux, et finalement, le mode de transport du pollen. Les services de pollinisation ont été mesurés en fonction de la nouaison et de la grenaison des pommes. La diversité fonctionnelle a été estimée en tenant compte des caractéristiques fonctionnelles et des valeurs d'abondance relative des abeilles, et cette estimation a été utilisée pour modéliser les services écosystémiques. La composition et la configuration des habitats naturels (boisés) et semi-naturels (en friche) dans les paysages autour des vergers étudiés ont été corrélées avec la diversité et les services de pollinisation fournis localement. L'incidence de la nouaison et la grenaison des pommes ont augmenté avec la diversité fonctionnelle des abeilles. La complémentarité dans l'utilisation des ressources entre les abeilles gérées et non gérées a été responsable de cette relation positive. La diversité fonctionnelle des abeilles a démontré une association positive avec la terre boisée et avec la terre en friche. La phénologie des espèces fleurissantes dans ces deux types de terrain se complète mutuellement dans leur fourniture des ressources pour les abeilles. Nous voulons mettre en place des objectifs de conservation des habitats boisés et en friche afin de favoriser la diversité fonctionnelle des abeilles sauvages et les services de pollinisation. Une identification des espèces d'abeille sauvage les plus utiles à la pollinisation a été entamée, et nous avons discuté de leurs besoins en fonction de la composition et de la configuration du paysage.
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Wunnachit, Wijit. "Floral biology of cashew (Anacardium occidentale L.) in relation to pollination and fruit set." Adelaide Thesis (Ph.D.) -- University of Adelaide, 1991. http://hdl.handle.net/2440/21622.
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Title page, contents and abstract only. The complete thesis in print form is available from the University Library.Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1991
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Barros, Mariluza Araujo Granja e. "Studies on the pollination biology and breeding systems of some genera with sympatric species in the Brazilian cerrados." Thesis, University of St Andrews, 1990. http://hdl.handle.net/10023/2925.
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Flowering phenology, floral strategies pollinator activity and breeding system were investigated in 14 species of the cerrado vegetation in Braeflia (DF), from April 1985 to April 1986 in Tabebuia caraiba (Mart.) Bur., T. ochracea (Cham.) Standl.; Erythroxylum campestre St. Hil., E. suberosum St. Hil., E. tortuosum Mart.; Diplueodon crulsianue Pohl., D. oblongus Pohl., D. ramosissimus Pohl., D. roomarinifolius St. Hil., D. villosus Pohl.; Kielneyera abdita Saddi, K. coriacea Mart., K. speciosa St. Hil. and K. variabilis Mart. The species occur sympatrically, often only a few meters apart, and conspecifics frequently occur in clumps. The majority of the species flowered during the dry season (May to August) except D. oblongue, D. villosue and K. speciosa which flowered during the wet season (December to March). Most of them flowered for several months except Tabebuia (one month). The most frequent flowering pattern was the "Cornucopian"' type, except for D. crulsianue and D. Villosus which were "Steady-State" types. Most congeners flowered synchronously, except K. speciosa which showed displacement. Flowers of all species are pollen donors (Tabebuia and Erythroxylum also have nectar rewards), but each genus presents specific floral strategies; Tabebuia, Massflowering, Erythroxylum, distyly and cauliflory, Diplueodon, enantiostyly and Kielmeyera, andromonoecy. Flowers were visited by a large spectrum of bees (38spp. ) and Erythroxylum were also visited by wasps (16 app. ). However, each genus had particular pollen vectors. Tabebuia; Centris and Bombus; Erythroxylum: wasps; Diplueodon; Apia and Trigona; and Kielmeyera; Xylocopa, despite the fact that other bees occur all year round. Controlled pollination experiments (self-, intraspecific-, interspecific crosses, tests for apomixis and from untreated bagged flowers), revealed that all species have a high outcrossing level and are selfincompatible. Only E. campeatre (shrub), D. crulsianus and D. villosus (hemixyles), showed some self-compatibility. Fluorescence microscopy indicated that pollen tubes from selfing and from interspecific cross pollinations were blocked in the ovary, suggesting that the selfincompatibility barrier operates late. Only in Erythroxylum the blockage occurred in the stigma (Thrum flowers) or in the style (Pin flowers). Fruit-set number from hand-pollinations and from natural pollination were low, but the former frequently yielded a higher number of fruits than the latter. Low fruit-set was associated with lack of resources allocated by the maternal parent for fruit maturation. In addition, it seemed that, in all species, many flowers were programmed to be pollen donors only, since they dropped without any sign of ovary enlargement even if they were hand-pollinated or were frequently visited by pollinators.
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Schmucki, Reto. "Demography and pollination ecology of «Trillium grandiflorum» in hedgerow corridors and forest patches." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32367.
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Hedgerows are assumed to provide suitable habitats and dispersal corridors in agricultural landscapes for forest herbs, but these functions have rarely been tested. Assuming that hedgerows can sustain viable populations solely from vegetation survey can be misleading since it does not take into account extinction lag and demographic processes. I address the question of hedgerow's suitability for forest herbs by comparing the demography and pollination biology of Trillium grandiflorum in hedgerow corridors and forest patches of an agricultural landscape. Specifically I ask: Do population structure and individual performance of T. grandiflorum differ between hedgerows and forests? Are pollination services comparable in hedgerows and forests? How do variations in growth, survival, and reproduction influence demography in hedgerows and forests? Individual plant performance and population structure was determined from field observations and experiments conducted in a system of hedgerows connected to forests. I conducted pollination and transplantation experiments to test for variation in pollination and reproduction among habitats and with increasing isolation. Populations monitored for three years in hedgerows and forests were used to construct transition matrix models and to compare their dynamics. Populations in hedgerows were characterized by lower proportion of seedling and juvenile per mature plant, but also by better flower and ovule production than in forests. Pollen limitation was comparable between habitats, suggesting that pollination services in hedgerows are at least as good as in forests. Pollination varied at the landscape scale and over time, and declined wiPrésumer que les haies peuvent servir de corridors de dispersion et contenir des populations d'herbacées forestières viables sur la seule base d'inventaires de la végétation peut être biaisé puisque ceux-ci ne tiennent pas compte du délai d'extinction ni des processus démographiques. J'aborde la question de la qualité des haies en tant qu'habitat en comparant la démographie et la pollinisation de Trillium grandiflorum dans des haies et des forêts. Est-ce que la structure des populations et la performance individuelle diffèrent dans les haies des forêts? Est-ce que les services de pollinisation sont comparables entre haies et forêts? Comment des variations dans la croissance, la survie, et la reproduction influencent la démographie dans chacun de ces habitats? La performance individuelle et la structure des populations ont été dérivées d'observations et d'expériences effectuées en haies et en forêts. Des expériences de pollinisation et de transplantation ont été utilisées pour tester les effets d'habitats et d'isolement sur la pollinisation et la reproduction. Des suivis, effectués en haies et en forêts, durant trois ans ont servi à construire des matrices de transitions et comparer la dynamique des populations. Dans les haies, les semis et les juvéniles sont retrouvés en moins grandes proportions, bien que la production de fleurs et d'ovules y soit plus élevée qu'en forêt. La limitation de pollen ne diffère pas, suggérant que la pollinisation dans les haies est équivalente à celle des forêts. La pollinisation varie à l'échelle des paysages et du temps, ainsi qu'avec l'isolement. La faible survie des premiers stades affecte nég
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Cardel, Yuria. "Linking herbivory and pollination : costs and selection implications in Centrosema virginianum Bentham (Fabaceae: papilionoideae)." FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/2042.
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This research first evaluated levels and type of herbivory experienced by Centrosema virginianum plants in their native habitat and how florivory affected the pollinator activity. I found that populations of C. virginianum in two pine rockland habitat fragments experienced higher herbivory levels (15% and 22%) compared with plants in the protected study site (8.6%). I found that bees (Hymenoptera) pollinated butterfly pea. Furthermore, I found that florivores had a negative effect in the pollinators visitation rates and therefore in the seed set of the population.
I then conducted a study using a greenhouse population of C. virginianum. I applied artificial herbivory treatments: control, mild herbivory and severe herbivory. Flower size, pollen produced, ovules produced and seeds produced were negatively affected by herbivory. I did not find difference in nectar volume and quality by flowers among treatments. Surprisingly, severely damaged plants produced flowers with larger pollen than those from mildly damaged and undamaged plants. Results showed that plants tolerated mild and severe herbivory with 6% and 17% reduction of total fitness components, respectively. However, the investment of resources was not equisexual.
A comparison in the ability of siring seeds between large and small pollen was necessary to establish the biological consequence of size in pollen performance. I found that fruits produced an average of 18.7±1.52 and 17.7±1.50 from large and small pollen fertilization respectively. These findings supported a pollen number-size trade-off in plants under severe herbivory treatments. As far as I know, this result has not previously been reported.
Lastly, I tested how herbivory influenced seed abortion patterns in plants, examining how resources are allocated on different regions within fruits under artificial herbivory treatments. I found that self-fertilized fruits had greater seed abortion rates than cross-fertilized fruits. The proportion of seeds aborted was lower in the middle regions of the fruits in cross-fertilized fruits, producing more vigorous progeny. Self-fertilized fruits did not show patterns of seedling vigor. I also found that early abortion was higher closer to the peduncular end of the fruits. Position of seeds within fruits could be important in the seed dispersion mechanism characteristic of this species.
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Ingram, Steven, and Steven Ingram. "Pollination biology of four co-occurring Erica species from the Cape Peninsula, South Africa." Bachelor's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/23944.
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Although pollinators have been suggested to drive speciation in the Cape flora, this has not been tested for the largest, florally diverse Cape genus Erica. Speciation studies that focus on pollination biology often use floral syndrome characters to predict a species' functional pollinator group/s. The predictive power of these techniques has come under scrutiny, and hence in-situ observations have become highly important for confirming existing pollination syndromes. Here I performed pollinator observations and recorded various floral traits of four co-flowering, co-residing Erica species in the Kalk Bay mountains, South Africa. The predictive pollination syndromes were confirmed through direct observations in the field. E. ericoides and E. globella subsp. globella were confirmed as insect pollinated plants, and E. plukenetii subsp. plukenetii and E. abietina subsp. atrorosea were confirmed as bird pollinated plants. Interesting correlations between floral traits and visitation rates are also suggested.
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Nicholson, Charles C. "No Farm Is An Island: Pollinators And Pollination In Agricultural Landscapes." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/985.
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Productive, resilient and sustainable agricultural systems are required to meet the immediate needs of a burgeoning human population, while avoiding ecosystem collapse. Agriculture provides food, fiber, fuels and other products for our current population of 7 billion and is still the major livelihood for 40% of people worldwide. By replacing natural habitat and employing chemical inputs, agriculture also negatively impacts biodiversity and impairs the provision of ecosystem services. This poses a challenge for agriculture as these impacted services are often those required for high yielding and high-quality crop production. Evidence is accumulating that agricultural management can safeguard biodiversity and ecosystem services while maintaining production, but critical questions remain concerning how management actions are shaped by broader landscape pattern and how these actions influence service-providing organisms across space and time.
Through a combination of observational, experimental and modeling approaches, my dissertation examines relationships between management actions, landscape pattern and service-providing organisms using crop pollination by wild bees as a model system. First, I investigate how local management and landscape pattern interact to affect pollination services and the abundance and diversity of native bees in Vermont, USA. I then use two established models of pollinator foraging to investigate whether one popular intervention, enhancing floral resources, improves crop visitation, and whether pollinator traits and landscape pattern influence this effect. Next, I use a national data set of native bee diversity to test whether habitat enhancements increase taxonomic and functional diversity of native bee communities. Finally, I investigate whether resource continuity provided by consecutively blooming crops benefits wild bee communities. These four chapters contribute ecological knowledge of plant-animal interactions in anthropogenic landscapes. My findings also provide land managers with clear information about the effects of landscape conservation and farm management on crop pollinators.
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Nilsson, Emil. "Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb Plantago maritima." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4790.
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Burdine, Justin D. "Factors influencing bee communities and pollination services across an urban environment." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1554460864439054.
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Jenkins, Miriam M. "Density Effects on Competition for Pollination between Two Wetland Plants." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1405376639.
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Walsh, Ryan Patrick. "Pollination Ecology and Demography of a Deceptive Orchid." Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1372097140.
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Wethington, Susan Marie. "Some effects of variability in nectar renewal-rates on the hummingbird-foraging/plant-pollination mutualism." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284254.
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How does variability in nectar secretion rates affect the interaction between hummingbirds and the plants that: they pollinate? Other researchers have suggested that variability may influence pollinators to leave a plant earlier, thus increasing the potential for cross-pollination. My dissertation asks the following questions: Does variability in nectar secretion rates influence hummingbird visitation at a flower patch? Does it do so in a manner that is likely to increase; cross-pollination? And, does variability in these rates benefit the hummingbird by improving their foraging efficiency? By asking if variability benefits both plants and hummingbirds, I implicitly ask the question: Can variability in nectar secretion rates be a mechanism that helps keep this potentially antagonistic interaction positive? I developed an artificial flower that simulates nectar secretion. Using patches of these artificial flowers, I varied renewal rates of flowers found within a patch. The appendices describe the results of my studies. The aviary experiment (Appendix A) investigates how Broad-billed hummingbirds (Cynanthus latirostris) forage given variability in nectar renewal-rates. The field experiment (Appendix B) investigates how hummingbird visitation to patches with different renewal-rates might affect cross-pollination. Appendix C describes the hummingbird community at the study site. Appendix D identifies the plants visited by these hummingbirds. In the aviary experiment, Broad-billed hummingbirds changed their foraging when exposed to high variability and limited nectar. They visited a higher percentage of rewarding flowers, foraged more systematically, and significantly decreased their foraging time. These changes made their foraging more efficient. In the field experiment, increased renewal-rate variability was associated with hummingbirds visiting fewer artificial flowers per foraging bout. These results suggest cross-pollination may be increased. However, levels of renewal-rate variability did not affect the visitation rates to the flower patch or the distribution of nectar within the patch. Hummingbirds spent significantly more time probing the last flower in a foraging bout than other flowers, and preferentially ended foraging bouts on a rapidly renewing flower. I suggest that the energetic cost of hovering flight likely influenced this behavior. My results support the hypothesis that variability in nectar secretion rates may benefit both partners in this pollination mutualism.
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Davidson, Jacob B. "Natural History and Breeding System of Maguire Primrose." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/696.
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The goal of this thesis was to examine the breeding system and natural history of the Maguire primrose (Primula cusickiana var. maguirei). Maguire primrose is an endemic, threatened subspecies found only along a narrow corridor within Logan Canyon in northern Utah, USA. This plant displays distinct flower distyly, with clear distinction of pin and thrum morphologies (morphs). The timing of Maguire primrose flower blooms was disparate between upper and lower canyon populations, and the flowers experienced cool temperatures occasionally. I captured eight different species of flying insects visiting Maguire primrose flowers, and made 67 observations of insect visitation. Inter-morph outcrossing hand pollinations were the most successful hand pollinations performed, but were usually not as successful as those that were naturally pollinated. Selfing rates were quite low compared to outcrossing reproductive scenarios. Morph-specific fecundity differences were detected in my hand pollinations, but not in the naturally pollinated maternal plants. I did not observe clear fecundity differences based on the canyon location of Maguire primrose.
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Raleigh, Ruth Elizabeth, and Ruth e. raleigh@dse vic gov au. "Propagation and biology of arachnorchis (orchidacae) and their mycorrhizal fungi." RMIT University. Department of Biotechology and Environmental Biology, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20091007.144548.
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Terrestrial orchids make up one of the most threatened groups of plants in Australia and the genus Arachnorchis is listed as the fourth most threatened. The process of propagation and re-introduction of terrestrial orchid plants to the wild has proven difficult, and so far, nearly impossible for some species. This may be partly because terrestrial orchids form complex relationships with mycorrhizal fungi and in genera like Arachnorchis the dependency on the fungus appears acute. Arachnorchis has long been considered by amateur growers of terrestrial orchids as one of the most difficult groups to propagate and maintain in cultivation. This lack of knowledge on how to grow Arachnorchis species hinders attempts made by conservation authorities to supplement threatened wild populations in order to achieve a more sustainable future for those species. Natural pollination was absent, but artificial pollination achieved 100% capsule production. Individuals were self-fertile, although seed viability was greater for cross-pollinated samples. This study attempted to track the fate of as many Arachnorchis species as possible from germination through to deflasking and re-emergence, and so destructive and potentially destructive measurements at earlier stages were avoided. This thesis examines germination and subsequent growth of up to eight species of Arachnorchis, but concentrated on A. phaeoclavia, A. tentaculata, A. fulva, A. robinsonii and A. venusta. Two of these are common species: A. pha eoclavia and A. tentaculata, and three carried a threatened classification of "rare" or " endangered": A. fulva, A. robinsonii and A. venusta. This study monitored the fate of individuals of the endangered A. fulva in the field and showed that large reproductive plants re-emerged and flowered each year, whereas smaller individuals might be absent in one or more years and were less likely to flower. Germination of all species concentrated on using symbiotic culture (using mycorrhizal fungi), since germination is known to be more rapid, resulting in healthier, more robust seedlings than when plants are grown asymbiotically. Tests using A. fulva and A. venusta, two threatened species, showed similar viability to A. tentaculata and A. phaeoclavia, more common species. Germination was maximised by examining the viability of seeds before and after treatment with surface-sterilising solutions required for aseptic culture. The highest levels of germination, with limited contamination, were achieved using 0.5% available chlorine for 3 minutes. The most effective fungal isolates (>65% germination) were obtained from common species like A. phaeoclavia and A. tentaculata, but there was no correlation between germination and time of year or life stage of the orchid. Collar collection was shown to be non-fatal to robust orchid plants, with large reproductive individuals (at the time of collar collection) re-emerging in the next year and producing a flower bud. Collar collection from small, weedy individuals could be fatal to the plant and isolation of an effective fungus was unlikely. Cross-inoculating seeds with fungi isolated from a different orchid species was not recommended, since the symbiosis failed in all experiments, as late as Stage 4 protocorm development. A range of substrates was used to produce strong seedlings capable of surviving the transfer to nursery conditions with minimal loss. More than 81% of seedlings survived deflasking from non-agar substrates, while the best result from agar was 55%. Some substrates reduced the time involved from seed to plants in the field to as little as 4 months, but aftercare became critical. Sucrose promoted tuberisation, but led to tuber deaths during dormancy. Potting mixes were tested in the nursery and a free-draining loam mix based on a mix used by the Australasian Native Orchid Society was the best medium for deflasking of seedlings. Watering during dormancy should be avoided. The choice of propagule for re-introduction was examined and the best survival to re-emergence was obtained by planting out actively growing seedlings in autumn. Identification of cultures using classical morphology grouped cultures as belonging to the form-genera Epulorhiza and Moniliopsis and suggested that most cultures contained more than one fungus. Identification of the most useful fungal cultures was attempted using molecular techniques such as sequencing the ITS region and mitochondrial DNA. One effective culture, CALAPHAER18 SHTX (cultured from a single monilioid cell) was identified as Serendipita vermifera (Oberwinkler) Roberts. All other cultures tested were mixtures of fungi. The use of specific primers designed to amplify a sequence present in the identified isolate (CALAPHAER18 SHTX) showed that nine mixed cultures also contained a fungus most closely related to Serendipita vermifera. Specific primers also showed that Rhizoctonia solani was not present in any of the 10 isolates from Arachnorchis plants. The molecular work showed that, although the sequenced endophytes from Arachnorchis were all most closely related to Serendipita vermifera, three dist inct groups of fungi were present and these associated with separate species of Arachnorchis. Future work with Arachnorchis species will require the isolation of single fungus cultures and further examination of the development of the orchid plant. In particular, the process of tuberisation and growth in vitro on various non-agar substrates should be investigated further.
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au, M. Wheeler@murdoch edu, and Margaret Wheeler. "Reproductive and Molecular Biology of Eucalyptus marginata." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040723.140250.
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This thesis examined aspects of the reproductive and molecular biology of Eucalyptus marginata (jarrah). The aims were to develop protocols for controlled pollination, that could be used in clonal orchard trees to breed jarrah seedlings that have a known genetic resistance to Phytophthora cinnamomi (dieback), for use in rehabilitation after mining and logging. An intimate knowledge of the breeding biology of jarrah was necessary to achieve this aim. The project also aimed to increase knowledge of the genetic diversity and structure of jarrah, in order to make informed decisions regarding the collection of material to be used for clonal propagation. Previous research has had little success in producing viable seed from any controlled pollinations, but clonal material resistant to P. cinnamomi has been produced using tissue culture. The question posed in this thesis was Can we improve breeding and propagation techniques of jarrah?
Techniques were developed for testing of in vitro pollen viability and pollen storage, pollination and fertilisation success after controlled pollinations, including determination of stigma receptivity and development of bud isolation techniques using alfoil. The variation in female fertility between genotypes was examined. The use of paclobutrazol was explored as a method of increasing the level of viable seed production in clonal orchard trees. The use of fertiliser as well as the growth retardant was also explored to see if it increased the level of seed production even more. Genetic diversity, genetic differentiation and phylogeny within Eucalyptus marginata were examined using nuclear and chloroplast DNA analysis with Restricted Fragment Length Polymorphisms.
While it was first thought that the fertilisation rate was quite low, it was confirmed that the fertilisation rate is similar to other eucalypt species. The zygote abortion rate was quite high in one clone, but one wild tree had a similar seed production rate to other eucalypt species. The zygote and endosperm appeared to be different in the clone and the wild tree observed. The level of seed production was examined in clones and wild trees and it was found that the level was often quite low, particularly in the clones (0 13% in clones, 0 18% in wild trees) in comparison with other Eucalyptus species, and varied between genotypes. The use of a growth retardant such as paclobutrazol may increase the production of viable seed, if it is applied during autumn. The results were inconclusive for the fertiliser/paclobutrazol experiment, since the paclobutrazol was applied during spring which was the worst time of year for increasing seed production. There were differences between genotypes in reaction to both the paclobutrazol and the fertiliser/paclobutrazol. Genetic diversity was moderate in comparison with other Eucalyptus species, and there was a low level of genetic differentiation between populations in the nuclear genome. No differentiation was observed between the morphologically recognised subspecies in the nuclear genome, but differentiation between the populations on the Swan Coastal Plain and populations on the Darling Plateau was seen in the chloroplast genome, indicating that there was historical separation of these two areas.
The conclusions arising from this work are that while controlled pollinations are possible in Eucalyptus marginata the clones that were used in these experiments have often behaved differently to the wild trees in the time of anthesis and levels of viable seed production, and in one clone (5J119) the zygote and endosperm nuclei appeared to be very different to the zygote and endosperm nuclei of a wild tree. Further investigation is necessary to see if these differences are related to the low level of seed production observed in the clonal populations. Paclobutrazol may be worth exploring further as a means of increasing seed production. Material to be used for rehabilitation and seed orchards can be collected from a wide area in the main distribution of the species, although trees on the Swan Coastal Plain are distinct from the trees in the main forest area in the chloroplast genome.
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Moore, Matthew Robert. "Disentangling the phenotypic variation and pollination biology of the Cyclocephala Sexpunctata species complex (Coleoptera: Scarabaeidae: Dynastinae)." Thesis, Wichita State University, 2011. http://hdl.handle.net/10057/5034.
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Researching cryptic biodiversity is an integrative process that uses a “total evidence” approach to identify population-level evolutionary lineages (species). Cryptic species of aroids have been discovered but the existence of cryptic pollinator species has not been addressed. The highly polymorphic scarab beetle, Cyclocephala sexpunctata, is a hypothesized pollinator of two cryptic aroid species. This research integrates detailed morphological data, spatial and distribution data, mitochondrial CO1 sequence data and host plant associations to test the hypothesis that cryptic species of Cyclocephala are visiting aroid flowers. Nine morphologically similar Cyclocephala species were included to address identification problems among similar species. A new country record was found for C. pan (Honduras). A female paratype specimen of C. letiranti was determined to be a female C. sexpunctata raising the possibility that there are no female type specimens of C. letiranti. Four unique male paramere forms (morphotypes) were found in C. sexpunctata and the allied species C. brevis. These paramere forms were associated with four female morphotypes that have a diagnostic form of the ventral surface of the epipleural pillow. The ventral form of the female epipleural pillow is described here for the first time and is a new character for the genus Cyclocephala. Detailed elevational and distribution data indicate that the morphotypes of C. sexpunctata and C. brevis are rarely collected together at specific localities. A checklist of cyclocephaline floral associations was compiled. Examination of voucher specimens and published floral associations indicate that the morphotypes described here visit different species of flowers within their hypothesized elevational range. Mitochondrial CO1 data demonstrate that C. sexpunctata is polyphyletic but the monophyly of C. brevis could not be addressed. The combination of these datasets indicates that the morphotypes described here are cryptic species though their taxonomy remains unresolved due to large numbers of synonyms.Thesis (M.S.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences.
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Howpage, Daya, of Western Sydney Hawkesbury University, Faculty of Environmental Management and Agriculture, and Centre for Horticulture and Plant Sciences. "Pollination biology of kiwifruit : influence of honey bees, Apis mellifera L, pollen parents and pistil structure." THESIS_FEMA_HPS_Howpage_D.xml, 1999. http://handle.uws.edu.au:8081/1959.7/338.
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The importance of European honey bees in improving fruit set, yield and fruit weight of kiwifruit on the central east coast of Australia was investigated. Field investigations were carried out using different bee saturations and different types of male pollen parents. These investigations confirmed the importance of honey bees in kiwifruit fruit set, yield and fruit weight. However, the results suggested that increasing bee activity alone may not increase pollination of kiwifruit by honey bees. Many factors need to be understood before introducing bees into the orchard. Bees were more effective during the early part of the flowering period, and bee activity varied according to the sex of the vine, planting design and the time of day. The type of male pollen parents also influenced fruit size and quality. Flowers pollinated by different pollen parents were assessed for pollen tube growth and histochemical changes. The resulting fruit were also examined for weight and seed numbers. Honey bees play the major role in the size and yield of kiwifruit, but the design of male vines, their age and type of male pollen may also contribute. The kiwifruit pistil also possesses important features that can be considered as adaptations to insect pollination.Doctor of Philosophy (PhD)
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Howpage, Daya. "Pollination biology of kiwifruit : influence of honey bees, Apis melllifera L, pollen parents and pistil structure /." Richmond, N.S.W. : Centre for Horticulture and Plant Sciences, University of Western Sydney, Hawkesbury, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030509.153106/index.html.
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Soley, Nathan. "Reproductive Biology of the invasive plant Elaeagnus umbellata: breeding system, pollinators, and implications for invasive spread." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1164.
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Reproductive studies in invasive plants are necessary for an understanding of their potential to establish and spread in foreign environments. Elaeagnus umbellata Thunb. (autumn olive) is an invasive woody shrub that flowers early in the spring and is often noted for its abundant fruit set. This study examined the reproductive biology of E. umbellata in Illinois, where it is highly invasive. Hand-pollination experiments were performed to determine the breeding system of E. umbellata, and floral visitors were collected to determine its pollinators. Experiments showed that E. umbellata is a predominantly outcrossing species with a self-incompatible breeding system. However, individual variation was detected in several reproductive characteristics. Pollen tube analyses revealed that a small percentage of individuals allow successful self-pollen tube growth, and self-fruit set resulting from automatic self-pollination (autogamy) was relatively high in a few plants. Automatic self-pollination is possible because the male and female parts of flowers mature sychronously, but the likelihood of autogamy may vary among individuals due to variability in the spatial separation of male and female parts (herkogamy). Variability in the incompatibility system and the level of herkogamy may impact the outcrossing rates and reproductive success of individuals. The majority of floral visitors to E. umbellata were generalist pollinators. Frequently visiting bees included small and large species such as native Andrena spp., Augochlorella aurata, Bombus spp., Ceratina calcarata, Xylocopa virginica, and the introduced Apis mellifera. Bombylius major (large bee fly) and the moth Mythimna unipuncta (armyworm) were also frequent visitors. Most of the above insect taxa are pollinators of E. umbellata based on analysis of pollen on insect bodies. E. umbellata is likely to achieve its abundant fruit set where these common pollinators and other E. umbellata are present. However, in my study sites, many individuals experienced low fruit set on branches that were open to pollinator visitation, suggesting pollen limitation may be common in some years and at certain sites. The discovery of autogamous individuals demonstrates that some E. umbellata individuals may be able to establish and spread even when mates or pollinators are limiting.
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Daniels, Jesse. "Direct and indirect effects of invasive Cirsium arvense on pollination in Southern Appalachian floral communities." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/124.
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To date, 13168 plant species have been naturalized outside their native range. While invasive plants efficiently compete for resources, they can also disrupt vital mutualisms. Pollination is a crucial mutualism required for 87% of flowering plants to reproduce. Invasive species may disrupt patterns of pollinator visitation, pollen transfer dynamics (conspecific [CP] and heterospecific [HP]), and reproductive success. Furthermore, whether invasive species’ effects depend on scale (site vs. patch) is not known. Thus, it is critical to understand the effects of invasive plants at all stages of pollination and how those effects vary with scale. Here, I investigate pollinator visitation, CP and HP deposition, and pollen tube growth between local flowers in sites and plots invaded by Cirsium arvense. For 7 weeks (June-July), pollinator visits were recorded and styles collected from an invaded and non-invaded floral community. Styles were processed for fluorescent microscopy. The number and identity of pollen grains on stigmas and the number of pollen tubes at style bases were recorded. The invaded site received significantly less visits than the non-invaded site, but the effect varied by species. This variation is not explained by local species’ abundance or floral symmetry. Similarly, invaded plots received significantly less visits than non-invaded plots, and no plot-species interaction was found. The invaded site received more CP and HP while invaded plots received less CP and HP. There was no difference in pollen tube growth between sites or plots. My preliminary results suggest that C. arvense affects pollinator visitation and pollen transfer dynamics in local floral communities, but the effects vary depending on species and scale. Conversely, these effects do not seem to lead to differential reproductive success between invaded and non-invaded communities at any scale.
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Soule, Jacob W. "Heterochrony of floral and mating system characters between Nicotiana longiflora and N. plumbaginifolia." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5001.
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Thesis (M.A.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 6, 2007) Includes bibliographical references.
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Broderick, Shaun Robert. "Pollination-Induced Gene Changes That Lead to Senescence in Petunia × hybrida." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408958432.
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Klips, Robert A. "Inbreeding depression, autonomous self-pollination, and the genetic affinities of a rare taxon within the rose-mallows, Hibiscus section Muenchhusia /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487862399447942.
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Berry, Eric J. "Population ecology of the harvested understory palm Chamaedorea radicalis pollination biology, female fecundity, and source-sink population dynamics /." Oxford, Ohio : Miami University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1151350945.
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Gadd, Laura Elizabeth. "Pollination biology of the federally endangered Echinacea laevigata (Boynton and Beadle) Blake, Smooth Coneflower, in small, isolated populations." NCSU, 2006. http://www.lib.ncsu.edu/theses/available/etd-04262006-195943/.
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Echinacea laevigata (Boynton and Beadle) Blake, a federally endangered species, occurs in several small, isolated populations and a single large population in the northern Piedmont of North Carolina. Currently, little is known of the reproductive biology of this species. Therefore, we sought to describe its flowering phenology, compatibility pattern, and which of its various flower visitors were the more effective pollinators, to inform conservation efforts. In addition, pollinator limitation can reduce seed number and seed quality in small, isolated plant populations. We conducted a study of insect flower visitation and seed production in these populations to test our hypothesis that plants in the small, isolated populations are visited by fewer insect taxa, receive fewer visits, and produce fewer and/or less fit seeds than do plants in the large population. Our data show that average insect visitor species richness was significantly greater in the large population than in small populations and all but one of the small populations had fewer pollinator visits per head during fifteen minute observations than the large population; however, plants in several small populations produced as many or more seeds per head than did plants in the large population. Therefore, our results were not consistent with expectations of pollinator limitation. However, results show that seeds from small populations produce seedlings that are less fit as those from the large population. We conclude that other factors not examined in this study are more threatening to small, isolated coneflower populations than is pollinator limitation.
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Thompson, Jessica Sara. "Pollination Biology of Ailanthus altissima (Mill.) Swingle (Tree-of-Heaven) in the Mid-Atlantic United States." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32586.
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To date little information has been collected on the pollination biology of Ailanthus altissima (Mill.) Swingle (tree-of-heaven), an invasive exotic in the U.S. This study was conducted to determine the insect pollinator fauna visiting A. altissima and to study general pollinator visitation patterns associated with the treeâ s nectar profile. A list of taxa visiting trees within each of three sites was developed from collected insects. Overall, visitor assemblage was dominated by the soldier beetle Chauliognathus marginatus with large numbers of ants in the genera Formica, Prenolepis, and Camponotus. No major diurnal pattern was found for visitation of insect pollinators using instantaneous counts. The nectar composition, concentration, and amount of total sugars in the flowers of A. altissima and how these are related to tree gender and time of day were determined. Nectar was found to be sucrose-dominant with lower, but nearly equal amounts of fructose and glucose. Total amounts of sugar in male and female blossoms were not statistically different, however higher concentrations of sugar were found in males (40.7%) than in females (35.3%). No difference was found over time. Nectar production and removal in trees was studied by comparing bagged flowers with flowers open to insect visitation. Bagged flowers were higher in overall sugar than open flowers, however, this was not constant across all times and gender.Master of Science in Life Sciences
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Clark, Jennifer Wester. "Determining the pollination mechanism of a problematic invasive species in the Gulf South: Triadica sebifera." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2134.
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Understanding the ecology of invasive species is vital to curb the homogenizing of ecosystems, yet the pollination mechanisms of the Chinese tallow tree (Triadica sebifera) in its introduced habitat remain ambiguous. This study examines self-pollination, wind pollination, and flower-visiting insects of tallow in a bottomland hardwood forest and Longleaf pine savannah in the U.S. Gulf South. These data suggest that self-pollination and airborne pollination are possible, but likely rare occurrences, although the possibility of apoxisis was not investigated. Seed production in exclusion experiments was significantly less than in open-pollinated flowers, and wind dispersal of tallow pollen dropped to essentially zero 8 meters from the source. Results show that tallow is primarily bee pollinated, with external pollen loads of Apis, Melissodes, and halictids visiting at similar rates, and Xylocopa species visiting less frequently. The researchers believe that to date, this is the first study of the pollination mechanisms of T. sebifera in its introduced range and recommend further study to understand the ecology of this destructive invasive species.
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Pang, Chun-chiu, and 彭俊超. "Floral biology, pollination ecology and breeding systems of selected Dasymaschalon, Desmos, Pseuduvaria and Uvaria species (Annonaceae) inSouthern China and Australia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47752737.
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The Annonaceae is a large, early-divergent family of angiosperms. Although the majority is pollinated by small beetles, there is a great diversity of floral morphologies. Evolutionary shifts of pollination mechanisms have occasionally been reported in disparate lineages including shifts to pollination by large beetles, flies, thrips, bees and cockroaches. It was previously hypothesized that floral morphological changes in different lineages are adaptive and correspond to evolutionary shifts of pollination mechanisms. This hypothesis is tested here by comparing selected species that have substantial morphological differences with their close relatives.
Comprehensive studies of the floral biology of four Annonaceae species, Dasymaschalon trichophorum, Desmos chinensis, Pseuduvaria mulgraveana and Uvaria cordata, are presented. All are beetle-pollinated. Dasymaschalon trichophorum, D. chinensis and U. cordata were inferred to be self-compatible based on inter-simple sequence repeat marker data as there was evidence of significant gene flow and a low level of genetic differentiation between populations. This was corroborated for D. chinensis and U. cordata by experimental controlled pollination tests for geitonogamy, in which both were shown to set fruit.
Similar floral phenological and pollination ecological results were obtained for D. chinensis and D. trichophorum despite significant differences in floral architecture, as the former has six petals (typical of most other Annonaceae species), whilst the latter only has three. The results suggested that the substantial change in floral morphology in these two closely-related genera is probably non-adaptive as there is no change in pollination system. It is hypothesised that the morphological change is likely due to the disruption of homeotic gene expression during floral organ development.
Studies of floral phenology and pollination ecology of Uvaria cordata revealed that it has a 3-day flowering rhythm and is pollinated by small beetles. The pollination ecology is unexpectedly similar to other species with typical beetle-pollination syndromes, although it lacks a pollination chamber and has pale-colored petals. It is suggested that species that lack a pollination chamber are more likely to be pollinated by guilds other than beetles or thrips as a floral chamber increases pollinator specificity. Several morphological and phenological characters are also presumably correlated with the evolution of generalist pollination to increase the pollination efficiency and assure fruit production, including torus shape, petal orientation, stigma shape, petal color, carpel and/or ovule number and the overlap of pistillate and staminate phases.
Pseuduvaria is unusual in the Annonaceae as the majority of species possess unisexual flowers. Most species were previously interpreted as having staminate and structurally pistillate flowers, with infertile staminodes in the latter. The ‘pistillate’ flowers of P. mulgraveana are shown to produce viable pollen, however, contradicting this hypothesis. It is therefore recommended that floral unisexuality in the genus be reassessed by testing more species from different clades.
Different strategies to promote xenogamy in the Annonaceae are reviewed, including protogyny, herkogamy, intra- and inter-individual phenological synchrony and dioecy. Three different mechanisms were recognized to achieve dioecy, including incomplete pollen development in hermaphroditic flowers, delayed anther dehiscence in hermaphroditic flowers and loss of androecium or gynoecium (with Pseuduvaria used as a paradigm).published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
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Andrikopoulos, Corey J. "Comparative Pollination Efficacies of Bees on Raspberry and the Management of Osmia lignaria for Late Blooming Crops." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7086.
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Unlike other rosaceous fruit crops such as apple and cherry, commercial raspberry cultivars are largely self-fertile and can set fruit in the absence of pollinators. However, their floral morphology often prevents complete self-pollaintion. Incomplete pollination yields unmarketable small or crumbly fruits. Insect visitation is therefore essential to maximizing raspberry yield. Honey bees are typically used to pollinate commercial raspberry; however, escalating prices for hive rentals coupled with increasing acreage encourage evaluation of other manageable pollinators. Bumble bees (Bombus spp.) and several mason bees (Osmia spp.) are promising raspberry pollinators. Five bee species were evaluated and compared for their single-visit pollination efficacies on raspberry. From this a pollinator effectiveness index was created and an estimation of the minimum number of visits required to maximize fruit set was calculated. This estimation was then experimentally verified. Finally, in an attempt to synchronize their brief activity period with raspberry bloom, winter management options aimed at delaying the emergence of the mason bee, O. lignaria, were investigated. All five bee species proved excellent pollinators of raspberry. None of the alternative manageable species greatly outperformed honey bees. For this reason honey bees remain the most economical and practical option for open-field raspberry pollination. The adoption of alternative manageable bees could still be justified in other production systems, such as high-tunnel or greenhouse grown raspberry, which hamper honey bees’ ability to forage effectively. The pollinator effectiveness score for honey bees suggested that as few as two visits can achieve maximum fruit set. This estimate was confirmed through experimentation on three different red raspberry cultivars. For two of these cultivars, just one visit yielded drupelet counts similar to openly-pollinated flowers. This information can be used to help refine stocking density estimates for honey bees on raspberry. Wintering bees at 0° or -3° C rather than 4° C effectively delayed emergence of O. lignaria by more than a month without any impact on post-winter performance. These results suggest winter storage at near freezing temperatures is a viable management option for the use of O. lignaria with later-blooming crops.
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Barrios, Roque Beyte. "Pollination, Herbivory, and Habitat Fragmentation: Their Effects on the Reproductive Fitness of Angadenia berteroi, a Native Perennial Plant of the South Florida Pine Rocklands." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/1902.
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Angadenia berteroi is a tropical perennial subshrub of the pine rocklands with large yellow flowers that set very few fruits. My dissertation seeks to elucidate the factors that affect the reproductive fitness of Angadenia berteroi a native species of the south Florida pine rocklands. I provide novel information on the pollination biology of this native species. I also assess the effects of herbivory on growth and the reproductive success of A. berteroi. Finally, I elucidate how habitat fragmentation and quality are correlated with reproductive fitness of this native perennial plant.
Using a novel experimental approach, I determined the most effective pollinator group. I used nylon fishing line of widths corresponding to proboscis diameter of the major groups of visitors to examine pollen removal and deposition. In the field, I estimated visitation frequency and efficacy of each pollinator type. Using potted plants, I exposed flowers to single visit from different types of pollinators to measure fruit set. I performed artificial defoliation with scissors on plants growing in the greenhouse to assess the effects of defoliation before flowering as well as during flowering. Additionally, I used structural equation modelling (SEM) to elucidate how A. berteroi reproductive fitness was affected by habitat fragmentation and quality.
My experiments provide evidence that Angadenia berteroi is specialized for bee pollination; though butterflies, skippers and others also visit its flowers, A. berteroi is exclusively pollinated by two native bees of the South Florida pine rocklands . This research also demonstrated that herbivory by the oleander moth may have direct and indirect effects on Angadenia berteroi growth and reproductive success. The SEM results suggested that habitat quality (litter depth and subcanopy cover) may favor reproduction in native species of the South Florida pine rocklands that are properly maintained by periodic fires and exotic control. Insights from this threatened and charismatic species may provide impetus to properly manage remaining pine rocklands in South Florida for this and other endemic understory species.
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Kinyo, Anthony Steven. "EFFECTS OF DISTANCE FROM INVASIVE LYTHRUM SALICARIA ON POLLINATOR VISITATION RATE AND REPRODUCTIVE SUCCESS IN NATIVE LYTHRUM ALATUM." University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1127925607.
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Stokes, Richard L. "Pollination Ecology, Self-incompatibility and Genetic Diversity in the Herbaceous Eastern North American Spring Ephemeral, Erythronium americanum." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1353089025.
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Martins, Giselle Alves. "Explicações funcionais na Biologia: o fenômeno polinização." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/59/59139/tde-28032016-103919/.
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Considerando explicações sobre o fenômeno polinização a partir de narrativas biológicas, este estudo foi norteado pela seguinte pergunta: até que ponto alguns termos, aparentemente finalistas, podem ser usados em textos científicos sem que ocorra um prejuízo no entendimento de questões ontogenéticas e filogenéticas? Diante esta questão, os objetivos desta pesquisa foram: i) apresentar uma discussão sobre as explicações funcionais na biologia, especificamente em relação ao fenômeno polinização e ii) contribuir para reflexões epistemológicas no ensino de Biologia. Foram selecionados dois filósofos para definições e análises sobre linguagens funcionais, Larry Wright e Robert Cummins. Para análise dos textos científicos sobre o fenômeno polinização, foi realizado o recorte de dois momentos históricos, um do século XVIII, quando se iniciou os estudos sobre polinização, e outro do século XIX, quando a teoria da evolução estava em discussão. As duas interpretações filosóficas defendem, embora de uma maneira distinta, a existência de uma ideia explanatória do conceito de função para a biologia. A concepção de Larry Wright (1973) sustenta que a função explica por que algo existe e a de Robert Cummins (1975) considera que o poder explicativo da função está na avaliação de sua contribuição para o sistema do qual faz parte, não sendo relevante para sua compreensão a informação sobre sua origem evolutiva. As duas obras científicas primárias selecionadas para análises, de Christian Sprengel (1750-1816) e Charles Darwin (1809-1882), apresentaram alguns termos aparentemente finalistas, ou seja, com conotação de caráter teleológico. A análise dos dados permite dizer que a questão sobre função na biologia é bastante inquietante. Tanto a ciência quanto a filosofia estão em processos de desvelar quais as melhores formas de tratamento de termos finalistas que satisfaçam os problemas de seu uso sem que ocorra um prejuízo no entendimento das questões evolutivas do fenômeno estudado. Este estudo sugere uma redução do uso de termos teleológicos em textos científicos, uma vez que há diferentes visões sobre este conceito, o que pode gerar interpretações incorretas. Além disso, as implicações deste estudo para a Didática da Biologia são apresentadas por meio de inserções filosóficas-epistemológicas em aulas de Biologia com o intuito de permitir o desenvolvimento dos conteúdos biológicos de forma mais reflexiva e contextualizada.Considering explanations about the phenomenon of pollination from biological narratives, this study was guided by the question: at what extent some terms, supposedly finalists, can be used in scientific texts without losses of ontogenetic and phylogenetic meaning? Therefore, the objectives of this research were: i) to present a discussion around functional explanations in biology, specifically in relation to the phenomenon of pollination; and ii) to contribute to epistemological reflections in Biology education. Two philosophers were selected for definitions and analysis of functional languages, Larry Wright and Robert Cummins. To the analysis of the scientific texts about the phenomenon of pollination, two historical moments were framed, one from the XVIII century, when the studies of pollination started, and another from the XIX century, when the theory of evolution was under discussion. Both philosophical interpretations defend, though in distinct ways, the existence of an explanatory idea of the concept of function to biology. Larry Wrights (1973) conception of function is that it explains why something exists, while Robert Cummins (1975) considers that the explicatory power of the function lies in the evaluation of its contribution to the system it belongs, but the information of its evolution history is not relevant to comprehend the function. Both primary scientific works selected for analysis, from Christian Sprengel (1750-1816) and Charles Darwin (1809-1882), presented some terms apparently finalists, which means, with teleological connotative character. The data analysis allowed saying that the inquiry about function in biology is quite intriguing. Science and philosophy are in process of unveiling the best approaches to finalist terms that would satisfy their usage problems without comprehension losses of the evolutive processes of the studied phenomenon. This study suggests a reduction of the use of teleological terms in scientific texts, since there are different analyses about the concept that may lead to misinterpretation. Moreover, the implications of this study to the Didactics of Biology are presented by means of philosophycal-epistemological inserts in Biology classes in order to enable the development of the biological contents in a more flexible and contextualized way.
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Millner, Helen Jean. "Reproductive biology and ex situ conservation of the genus Restrepia (Orchidaeae)." Thesis, University of Wolverhampton, 2013. http://hdl.handle.net/2436/311706.
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The genus Restrepia is well known to orchid enthusiasts but its micromorphology has not been described, and its pollination and breeding systems have not been investigated. The aim of this investigation was, therefore, to add to existing knowledge so that the resultant data could be used to facilitate ex situ conservation initiatives. A detailed electron microscopy study (SEM) of the floral organs was performed. This confirmed the structure of the dorsal sepal and lateral petal osmophores, their secretory nature together with that of the synsepal and the labellum. It was postulated how, by manipulating different labellar surface textures, the flower might use these ‘tactile guides’ to steer the insect (fly) through the flower. The cirrhi were postulated to help by destabilising the pollinator in flight, trapping it and bringing about pollination. The papillate structure of the calli was established and their optical properties investigated. Media comparison investigations established that Western medium supported the highest germination rates and, with the addition of banana supplement, the highest rates for seedling growth and development. This represented the first protocol for axenic germination of Restrepia in the literature (Millner et al., 2008) and provided a tested methodology for investigating breeding systems and producing Restrepia plant material for both scientific and horticultural purposes. Self-pollinations were found to produce fewer embryos compared to cross-pollinations. The operation of self-incompatibility (SI) was confirmed by the study of pollen tube growth which further confirmed the time interval between pollination and fertilisation. A time line from pollination/fertilisation to flowering was established. The type of SI in operation was best explained by gametophytic incompatibility. This demonstrated that it was possible to raise Restrepia hybrids and species from seed, by performing intraspecific crosses so helping to preserve them for posterity and relieve pressure on wild populations. Narrow endemic Restrepia species face combined threats from habitat loss, habitat degradation and problems of viable seed production due to the effects of SI and inbreeding depression (ID). Recently developed online resources, such as GeoCAT, were used to perform a Red List assessment in order to identify the degree of threat individual species faced, both globally and nationally. All species were classified as facing substantial levels of threat; although this was lessened for populations in protected habitats. Conservation is needed for cultivated collections as well as these wild populations by keeping alive existing knowledge and expertise in growing these species.
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Bell, Simon Alexander. "Investigating the pollination biology of oilseed rape (Brassica napus) with emphasis on the potential for floral display size to influenced by balancing selection." Thesis, University of Exeter, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337759.
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Watrous, Kristal M. "Reproductive Ecology of Astragalus filipes, a Great Basin Restoration Legume." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/617.
Full textAbstract:
Astragalus filipes Torrey ex. A. Gray (Fabaceae) is being studied and propagated for use in rangeland restoration projects throughout the Great Basin. Restoration forbs often require sufficient pollination services for seed production and persistence in restoration sites. Knowledge of a plant's breeding biology is important in providing pollination for maximal seed set. Reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy, and distant xenogamy) was examined in a common garden. Pod set, seed set, and seed germination were quantified for each of the treatments. Seed set from four wild populations was compared to that of an openly visited common garden array. A. filipes was found to be self-compatible, but to benefit greatly from outcrossing. Less seed germinated from distantly outcrossed treatments than for any other treatment, indicating possible outbreeding depression. Common garden plants set less seed per pod than any wild population, possibly due to a depauperate pollinator guild in the common garden. Bees were surveyed at wild A. filipes populations to identify common pollinators. Solitary and social bee species were observed visiting A. filipes to estimate aspects of their pollination efficacies, particularly foraging tempo and frequency of stigmatic contact. The nesting biologies of bees that visit A. filipes were considered as a component of bee manageability. Bees in the genus Osmia (Megachilidae) dominated this pollinator guild. Bombus nevadensis queens were the fastest foragers; honey bees and native solitary bees did not differ in foraging tempo. Megachilid bees consistently contacted the stigma during foraging, but honey bees exhibited sideworking behavior, contacting stigmas far less frequently than any other bee species observed. Two solitary bee species (Osmia bruneri and Hoplitis hypocrita) are recommended as prospective pollinators for management in association with Great Basin rehabilitation efforts.