Dissertations / Theses on the topic 'Endomycorrhizae'

Both lettuce and pepper crops are routinely grown as transplants in Quebec. Previous research has shown that both of these plants respond well to endomycorrhizae with a resulting improvement in plant growth and yield. Although many studies have been conducted on endomycorrhizal inoculation of transplants most were looking at the end result, i.e. yields, and did not focus on changes occurring at the transplant stage. This series of experiments was conducted to look at the effect of inoculation at the transplant stage. Lettuce (Lactuca sativa cv. Parris Island Cos) and pepper (Capsicum annuum cv. Hybrid Bell Boy) were inoculated with Glomus intraradix Schenck & Smith and Glomus versiforme (Karst.) Berch. Experiments involved testing the effect of different growing media, different container volumes and different light sources on the growth of endomycorrhizal lettuce and pepper transplants. In all experiments the amount of growth enhancement due to endomycorrhizal inoculation was low or negligible. Colonization rates were generally low, probably due to low light levels. Transplants grown in larger volume containers were generally larger than those grown in smaller containers. The transplants grown in the soil and compost based media were larger than those transplants grown in the artificial media. Growth of lettuce and pepper transplants was affected differently depending on the light source used. Some interactions between the light source and the endomycorrhizal treatments was observed.

Inoculation of Parthenium argentatum (guayule) with an endomycorrhizal fungus (Glomus intraradices) increased the growth of guayule in saline and non-saline soils low in available phosphorus. Addition of 100 ug/g of P as Ca(H2PO4)2 to soils low in available phosphorus was as efficient as G. intraradices in stimulating the growth of guayule. The concentrations and total plant accumulations of minerals within guayule shoots varied depending on growth of the plants and the minerals assayed. In most cases, the concentrations of Cu, Zn, Mn, Na and Cl increased in the shoot tissues of guayule grown in soils which contained added NaCl. Generally, addition of phosphorus to the soil resulted in decreased concentrations of Cu and Zn and increased concentrations of PO4 in guayule shoots. The total accumulations of minerals by guayule was directly influenced by the biomass of plants. Increased biomass of plants generally resulted in increased total accumulations of the minerals assayed. The influence of mycorrhizae on the accumulations of minerals by guayule grown in a saline soil was evaluated by comparing nonmycorrhizal plants with the same biomass and phosphorus nutrition as mycorrhizal plants. Mycorrhizae increased the concentrations and total plant accumulations of Zn and decreased the content of Cl within guayule shoots. Colonization of guayule roots by G. intraradices was not affected by addition of P to the soil. Addition of NaCl to the soil decreased the formation of arbuscules and vesicles within roots and increased the incidence in which no fungal structures were seen. The combination of P and NaCl added to soil had a synergistic effect on the mycorrhizae of guayule. Addition of both P and NaCl to soil reduced the occurrence of hyphae, arbuscules and vesicles within roots and decreased the overall infection of guayule roots by G. intraradices.

Bibliography: pages 133-144.
An investigation was undertaken on the phosphorus nutrition of the ericoid endophytes isolated from the root systems of Vaccinium macrocarpon, Aiton, Rhododendron ponticum L., Calluna vulgaris (L.) Hull, Erica hispidula L., and E. mauritanica L.

Onions are highly responsive to endomycorrhizae and improved plant growth is among the benefits associated with this symbiosis, particularly in low phosphorus soils. Although this crop is grown extensively in organic soils, few studies have been conducted on these. Onion plants (Allium cepa L. cv. Norstar) were inoculated with Glomus aggregatum Schenck & Smith, Glomus clarum Nicolson & Schenck, Glomus fasciculatum Gerdemann & Trappe, Glomus intraradix Schenck & Smith and Glomus versiforme (Karst.) Berch and grown in the field and under controlled conditions to evaluate their efficiency in newly reclaimed organic soil of low P fertility. Three species were selected to evaluate the effects of introduced endomycorrhizal fungi effects and P fertilization (equivalent to 0, 24 and 48 kg P ha$ sp{-1}$) on the growth and mineral nutrition of onion plants.
Introducing endomycorrhizal fungi in non-sterile soil did not affect the growth and mineral nutrition of onion. Crop maturity was advanced when plants were inoculated, however. Increasing levels of P fertilization did not depress root colonization and onion growth was increased significantly at the highest rate only. These results suggest that higher levels than recommended could be used in this soil. Inoculation in $ gamma$-irradiated (10 kGy, $ sp{60}$Co) soil alleviated excessive Mn absorption by onion plants. Adding P fertilizer depressed growth and root colonization when plants were inoculated with G. clarum and G. intraradix and was related to the low irradiance levels used in this study. G. versiforme appeared to be the most efficient of the introduced species.

The success of reafforestation schemes depends largely on the silvicultural systems employed. An indication of the ecological sensitivity of such practices can be gauged from the extent to which the soils physical, chemical and microbiological properties are altered. Of particular interest is the impact on the vescicular-arbuscular mycorrhizal (VAM) fungi as they play an important role in ensuring that forest trees especially those growing on nutrient deficient soils acquire sufficient mineral nutrients for growth. This study therefore set out to examine the effects of different methods of site preparation (Manual 'recru', mechanical 'recru' and complete clearance) and the subsequent outplanting with Terminalia ivorensis on the VAM population dynamics in the Mbalmayo Forest in Cameroon. Observations made prior to site preparation indicated the presence of an array of 17 VAM fungi belonging to the generas Acaulospora, Glomus, Sclerocystis and Scutellispora. Of the 17 fungi, one, Glomus etunicatum always represented more than 50% of the spore population. The importance of the tree component of the forest vegetation as reservoirs of VAM inocula was evident from, a) the higher number of spores in association with T. superba compared with shrubs and b) the peak in spore density close to T. superba trees (2.5m). Seasonal effects were suspected as many VAM fungi sporulated more profusely in the dry season (February, 1987) compared to the two rainy seasons (August 1987 and August 1988). Site preparation led to a dramatic reduction in spore number with the completely cleared plot losing 65% of its initial spore population. One year after planting, however, mean spore numbers had increased dramatically in all cleared plots, a major cause of the increase being the increase in root densities from the planted T. ivorensis and the invasive ruderal Eupatorium odoratum and pioneer tree Musangacecropioides. In the mechanically and completely cleared plots the sharp rise in spore numbers was mainly by the fungal aggregate G. occultum/A. scrobiculata which sporulated profusely in the presence of the invasive ruderal Eupatorium odoratum. The amounts of infection within the roots of T. ivorensis 1.5 years after planting in the manual and mechanical 'recru' plots were significantly greater than observed within T. ivorensis roots in the completely cleared plot. These differences may be related to the initial drop in spore numbers following site preparation, the disruption of the VAM hyphal networks in soil and/or the increasing dominance of G. occultum/A. scrobiculata, a type believed to be more associated with Eupatorium odoratum and hence possibly less effective on T. ivorensis. The value of the silvicultural procedures that were less destructive appeared to be reflected in tree survival.

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Blueberries are temperate fruit species of great economic importance that has stood out in Southern Brazil. The objectives of this study were to evaluate the influence of arbuscular mycorrhizal fungi (AMF) on the production of plantlets of blueberry, as well as isolate and identify these fungi from the orchards in the South - RS. Samples were collected from soil and roots in experimental and commercial of blueberry orchards in the municipalities Pelotas, Morro Redondo and Jaguarão and ecological indexes used as a measure populations in orchards in the study and principal components analysis to assess the physical and chemical soil in relation to the AMF. We identified 18 different morphotypes of spores. The percentages of root colonization with AMF were high, ranging from 40 to 80%. Since the varieties in commercial orchard located in the city of Morro Redondo city were the most colonized in relation to others. The greatest number of spores found in O'Neal in the orchard from Micaela. The relative abundance and the highest Shannon diversity index (H ') and richness (R) were found in the older areas of cultivation, old orchard at Embrapa (EPV) and the commercial orchard in the Morro Redondo city (MR). The relative frequency shows the prevalence of species of the genus Glomus and Acaulospora in all orchards. The dominance evaluated by the Simpson index (Is) showed the same trend as the Shannon diversity and richness. Among the chemical parameters of soil, there was a high correlation of AMF species with varying pH, V (%), P and sand. AMF isolates for the production of seedlings were provided by Bank of species of the Department of Horticulture and Forestry at UFRGS. Were tested four species of AMF (Glomus clarum, Glomus etunicatum, Gigaspora margarita and Scutellospora heterogama) on the production of cultivars Woodard and Bluegem. The AMF would have positive effects in the nursery, particularly Gigaspora margarita which provided better nutrition, and higher biomass of plants growing Woodard and Glomus etunicatum Bluegem for cultivation. The efficiency of the mycorrhizal symbiosis of blueberry cultivars, depends on the interaction specifies AMF X host.
O mirtilo é uma espécie frutífera de clima temperado de grande importância econômica que vem se destacando na região Sul do Brasil. Os objetivos desse trabalho foram avaliar a influência de fungos micorrízicos arbusculares (FMA) na produção de mudas micropropagadas de mirtilo, assim como isolar e identificar esses fungos oriundos dos pomares da região Sul - RS. Foram coletadas amostras de solo e raízes em pomares comerciais e experimentais de mirtilo dos municípios de Pelotas, Morro Redondo e Jaguarão e utilizados índices ecológicos como forma de avaliar as populações nos pomares em estudo e a análise de componentes principais para avaliar os atributos físicos e químicos do solo em relação aos FMAs. Foram identificadas 18 diferentes morfotipos de esporos de FMA. As porcentagens de colonização radicular com FMA foram elevadas, variando de 40 a 80%. Sendo que as variedades localizadas no pomar comercial do município do Morro Redondo foram as mais colonizadas em relação às demais. O maior número de esporos foi encontrado na variedade O‟Neal no pomar comercial da Micaela. A abundância relativa e os maiores índices de diversidade Shannon (H‟) e riqueza (R) foram encontrados nas áreas mais velhas de cultivo, pomar velho experimental da Embrapa (EPV) e do pomar comercial do município Morro Redondo (MR). A frequência relativa demonstra a prevalência de espécies do gênero Glomus e Acaulospora em todos os pomares. A dominância avaliada pelo índice de Simpsom (Is) apresentou a mesma tendência da diversidade de Shannon e da riqueza. Entre os parâmetros químicos do solo, houve uma alta correlação das espécies de FMA com as variáveis pH, V(%), P e areia. Os isolados de FMAs para a produção de mudas foram cedidos pelo banco de espécies do Departamento de Horticultura e Silvicultura da UFRGS. Testaram-se quatro espécies de FMAs (Glomus clarum, Glomus etunicatum e Scutellospora heterogama e Gigaspora margarita) sobre a produção de mudas das cultivares Woodard e Bluegem. Os FMAs proporcionaram efeito positivo na produção das mudas, em especial Gigaspora margarita que proporcionou melhor nutrição e maior incremento na biomassa nas plantas da cultivar Woodard e o Glomus etunicatum para a cultivar Bluegem. A eficiência da simbiose dos FMAs em cultivares de mirtilo, depende da interação especifica FMA X hospedeiro.

Nous avons réalisé une analyse fonctionnelle détaillée du promoteur du gène MtENOD11 au cours des infections endosymbiotiques et en réponse aux signaux spécifiques secretés par Rhizobium appelés facteurs Nod (FNods) qui jouent un rôle clé dans l'établissement de la syymbiose fixatrice d'azote. Nous avons identifié une région promotrice de 257 pb suffisante pour diriger une expression au cours de l'infection par Rhizobium, et de l'association endoymcorhizienne et lors de l'interaction parasitaire avec les nématodes à galles Meloidogyne incognita. Nous avons caractérisé un motif riche en AT requis à la fois pour l'expression associée à l'infection par Rhizobium et par les endomycorhizes, montrant pour la première fois des mécanismes similaires de régulation lors des infections endosymbiotiques raciniares. Nous avons ensuite caractérisé pour la première fois une unité régulatrice originale (appelée NF-box) suffisante pour conférer une expression dépendante des FNods et épiderme-spécifique. Nous avons également démontré qu'au moins trois sites de liaison de facteurs trans sont importants pour cette réponse. Enfin, nous avons initié des approches gènes candidats et un criblage simple hybride chez la levure pour identifier les facteurs trans impliqués dans l'activation de gènes par les Fnods
We have undertaken a detailed functional analysis of Medicago truncatula ENOD11 gene promoter during endosymbiotic infections and in response to specific rhizobial signals known as Nod factors (NFs), which play a key role in the establishment of the N-fixing symbiosis. First, we defined a 257 bp promoter sequence sufficient to direct expression during rhizobial infection, arbuscular endomycorrhizal (AM) fungi association and Meloidogyne incognita parasitic root knot nematode interaction. We characterized an AT-rich motif required for both rhizobial- and mycorrhizal-related infection, thus providing the first direct evidence for similarities in gene regulatory mechanisms during endosymbiotic root colonization. Subsequently, we were able to define a 33 bp novel regulatory unit (named NF-box), sufficient to confer NF-dependent, epidermal-specific expression. We further demonstrated that the NF-box unit comprises at least three adjacent trans-factor binding motifs which are important for this response. Finally, we initiated yeast one-hybrid screening and candidate gene approach to identify trans-factors involved in NF-mediated activation

Les endosymbioses racinaires sont des associations bénéfiques établies entre les racines des plantes et des micro-organismes du sol. Ces symbioses ont un intérêt agronomique et écologique puisque les plantes fournissent à leurs partenaires microbiens une niche écologique et des sucres issus de la photosynthèse et en retour, les micro-organismes associés aux racines vont fournir à la plante des nutriments minéraux qui sont actuellement apportés dans l’agriculture conventionnelle sous forme d’engrais. Durant ma thèse, j’ai particulièrement étudié la symbiose endomycorhizienne à arbuscules (AMS). Elle implique des champignons du groupe des Gloméromycètes et plus de 80 % des plantes terrestres. Ainsi cette symbiose est la plus répandue sur terre connue à l’heure actuelle. Plusieurs étapes importantes pour l’établissement de l’AMS ont été définies. La première de ces étapes est la reconnaissance mutuelle entre le champignon endomycorhizien et la plante hôte. Le champignon est capable de percevoir les plantes par les exsudats racinaires qu’elles sécrètent dans la rhizosphère. Dans le mélange complexe de molécules que sont les exsudats racinaires, des phytohormones appelées strigolactones activent le métabolisme des champignons endomycorhizien, la ramification des leurs hyphes et la production de molécules fongiques appelée facteurs Myc. La perception des facteurs Myc par la plante active des processus permettant la colonisation des racines par le champignon. Ce dialogue moléculaire entre champignons endomycorhiziens et plantes hôtes reste toutefois méconnu. Des molécules de type Lipo-chitooligosaccharides (LCO) ou chito-oligosaccharides (CO) ont été identifiées dans les exsudats de spores ou d’hyphes de champignons et activent la voie de signalisation symbiotique chez les plantes mais leurs rôles respectifs dans l’établissement de l’AMS restent mal compris. Du côté de la plante, des récepteurs potentiels aux LCOs et aux COs sont codés par les gènes de la famille des Lysin Motif Receptor-Like Kinase (LysM-RLK) qui sont capables de lier les constituants structuraux des LCOs et des COs. Cependant aucune preuve n’avait été apportée, au commencement de ma thèse, permettant de conclure sur le rôle des LCOs, des COs, et des LysM-RLKs dans la mise en place de l’AMS. C’est ce que je me suis attachée à démontrer durant ma thèse. Pour cela, j’ai travaillé sur une dicotylédone (la tomate : Solanum lycopersicum) et sur une monocotylédone (Brachypodium distachyon, un modèle pour le blé). Pour identifier les récepteurs aux LCOs dans ces plantes et déterminer leur rôle dans l’AMS nous avons mis en place des techniques de génétique inverse. Nous avons ensuite déterminé l’affinité de ces récepteurs pour les LCOs. Ainsi, nous avons montré que la perception des LCOs dans la tomate est importante pour la mise en place de l’AMS. Par ailleurs, je me suis intéressée à la symbiose entre des bactéries du type rhizobium et des plantes principalement de la famille des légumineuses. La mise en place de cette symbiose nécessite la synthèse de LCOs par les rhizobia et leur perception par la plante via des récepteurs de la famille des LysM-RLKs. Ces similarités que la symbiose rhizobium-légumineuses partage avec l’AMS nous ont conduits à poser la question de savoir si les récepteurs de LCOs impliqués dans l’AMS (beaucoup plus ancienne que la symbiose rhizobium-légumineuse) ont été recrutés durant l’évolution pour jouer un rôle dans la symbiose rhizobium-légumineuse. J’ai pu montrer que les récepteurs de LCOs impliqués dans l’AMS chez les espèces non-légumineuses susmentionnées sont fonctionnels l’établissement de la symbiose rhizobium-légumineuse chez une légumineuse
Root endosymbioses are beneficial associations established between plant roots and soil microorganisms. These symbioses have an agronomic and ecological interest as plants provide their microbial partners with an ecological niche and carbohydrates from photosynthesis. In return, the root-associated microorganisms provide the plant with minerals that are currently being delivered in conventional agriculture as fertilizers. During my thesis, I particularly studied the arbuscular mycorrhizal symbiosis (AMS). It involves fungi of the Glomeromycota group and more than 80 % of land plants. This is the currently known most widespread symbiosis on earth. Important steps for the AMS establishment have been defined. The first step is the mutual recognition between the endomycorrhizal fungus and the host plant. Fungi can perceive plants through the root exudates. In the complex mixture of molecules in the root exudates, phytohormones called strigolactones activate the endomycorrhizal fungal metabolism, the branching of their hyphae and the production of fungal molecules called Myc-Factors. Myc-Factors are perceived by the plant and activate a signaling pathway allowing root colonization by the fungus. However, parts of the molecular dialogue between endomycorrhizal fungi and host plants remain unknown. Lipo-chitooligosaccharide (LCO) or chito-oligosaccharides (CO) molecules have been found in exudates of fungal spores or hyphae and were shown to activate the plant symbiotic signaling pathway, however their respective roles in the AMS establishment are unclear. Putative plant receptors for LCOs and COs are encoded by genes from the Lysin Motif Receptor-Like Kinase family (LysM-RLK) which are able of binding the structural LCO and CO components. However, at the beginning of my PhD, we had no evidence allowing to conclude about the involvement of LCOs, COs, or LysM-RLKs in the AMS establishment. During my thesis, I aimed to understand the role the LCOs and their plant receptors in AMS. For this, I used on a dicotyledon (the tomato: Solanum lycopersicum) and on a monocotyledon (Brachypodium distachyon that is a model for wheat). In order to identify the LCO receptors in these two species, I used a reverse genetic approach. Then I determined these receptors affinity for various LCO structures. I showed that in tomato, LCO perception is important for AMS establishment. In addition, I have studied the symbiosis between rhizobium-type bacteria and plants of the legume family. Interestingly, the establishment of this symbiosis requires LCO synthesis by rhizobia and LCO perception by the plant via receptors of the LysM-RLK family. The fact that rhizobium-legume symbiosis shares similarities with the AMS led us to ask whether the LCO receptors involved in AMS (a much more ancient symbiosis than the rhizobium-legume symbiosis) have been recruited during evolution for a role in the rhizobium-legume symbiosis. I demonstrated that the LysM-RLKs involved in AMS in the above mentioned non-legume species are functional for the rhizobium-legumes establishment in a legume species

The Oak Ridge Reservation established under The Atomic Energy Commission was the site for uranium enrichment and the construction of the atomic bomb during the early 1950’s and 60’s. Unfortunately, large quantities of “heavy metals” such as mercury, uranium, technetium, plutonium and fission products that were produced were dumped into unlined landfills, settling ponds and surface streams. One such creek affected was East Fork Poplar Creek, whose head water begins at the Y-12 Facilities located on the Oak Ridge Reservation, and was once used as an industrial drainage ditch for runoff, which included mercury and other heavy metals. The release of mercury, in particular, into East Fork Poplar Creek was probably lethal to established seed banks, vegetation, and soil microbial and fungal communities. The soil microbial communities play an important role in ecological processes, and the fungal communities are important, in particular, due to the mutualistic associations shared with more than 85% of plant species. This study evaluating the long term effects of mercury on plant and fungal presence and abundance indicated that soil mercury concentration was not significantly correlated with these factors. In order to better understand the effects of mercury compounds on plant and fungal interaction, a greenhouse study was conducted. Survival of seedlings in mercury-contaminated media was more dependent on mercury compound applied than on the presence of fungal inoculates tested. The ability of four tree species to germinate in different mercury compounds was also investigated. The germination of seedlings in mercury solution was dependent on tree species, mercury compound and concentration. The detection of mercury in environmental samples was based on conventional methods such as cold vapor atomic absorption spectroscopy (CVAAS), and inductively coupled plasma emission mass spectrometer (ICP-MS). Analysis of mercury and other metals by non-destructive techniques such as infrared spectroscopy, specifically near-infrared (NIR) and mid-infrared (MIR) spectroscopy was investigated. Quantitative analysis of plant foliar tissue exposed to mercury was investigated by NIR, and mercury- contaminated soil was investigated by MIR. Due to mercury’s volatility, the ability to differentiate NIR spectra of control versus treated seedlings could not be confirmed through statistical analysis, however MIR spectra obtained from mercury-contaminated soil was used to develop significant calibration models for mercury and several other metals correlated to mercury.

博士
國立中興大學
植物病理學系所
103
Orchids can be divided into non-green (myco-heterotrophic) and green (mixotrophic) orchids. Green orchids have mycorrhizal associations with the form genus Rhizoctonia. With phylogenetic analysis and anastomosis group determination, mycorrhizal fungi in our study belonged to Thanatephorus, Tulasnella and Ceratobasidium. Tulasnella fungi distributed mainly in Epidendroideae, including T. calospora, T. danica and two unknown isolates. Ceratobasidium fungi (i.e., AG-A, AG-B, AG-G, AG-P and AG-R) were isolated from terrestrial orchids. Except for AG-A, 4 AGs of Ceratobasidium were found the first occurrence in Orchidaceae. Our results suggested that green orchids in the same geographic region associate with a diversity of Rhizoctonia groups. Furthermore, Thanatephorus (AG-6) and Ceratobasidium (AG-G, P, and R) were also identified in native A. formosanus from different geographic regions, suggesting that single orchid species exhibits diverse associations with Rhizoctonia fungi. Isolates of AG-6, AG-R and AG-P in Clade I increased seed germination 44–91% and promoted protocorm growth from phase III to VI compared to asymbiotic treatments (13%) and isolates in Clade II and III. Different levels of seed viability may affect the result of mycorrhizal symbiosis: a mycorrhizal interaction or a parasitic interaction. However, all isolates in Clades I to III formed fungal pelotons in tissue-cultured seedlings of A. formosanus. An analysis of the relative effect of treatment (p ̂_i) showed that the low level of colonization (p ̂_i = 0.30 – 0.47) by isolates in Clade I resulted in a significant increase in seedling growth compared to isolates in Clades II (0.63 – 0.82) and III (0.63 – 0.75) which caused moderate to high colonization in plant. There was also a negative correlation (r = -0.8801) with fresh plant weight and fungal colonization. Sections of A. formosanus mycorrhizome consisted of a non-digested zone and a digested zone. Both type I and II of symbiotic interface consisted of an electron-lucent layer and an electron-opaque layer; however, type II exhibited much thicker electron-opaque layer than type I. However, type III consisted of two electron-lucent layers and two electron-opaque layers with occasional nicks, which is first occurrence in orchid mycorrhizae. Pectin substances have been proved at symbiotic interface by using innunogld labelling for un-esterified homogalacturonan (HG). Un-esterified HG was recognized heavily at the interface of vacuolar hyphae. It seems that fungal activity is associated with the presence of pectin substances. However, methyl-esterified HG was only found in plant cell wall and middle lamella, and β-(1→3) / (1→6)-glucan was only found in fungal cell wall, especially at dolipore septum. Evaluating the virulence of endomycorrhizal Rhizoctonia fungi is important for the purposes on biological control against plant disease. All isolates, excepting the AG-R isolate, did not cause seedling death with low values of relative treatment effects for disease severity in 10-day-old radish (0.1 – 0.61), cucumber (0.28 – 0.54), and Chinese mustard (0.18 – 0.65); however, pathogenic AG-4 isolates resulted almost all the test plants died (0.88 – 0.96). AG-P isolate Cno10-3 and CalS1-2 exhibited 91% and 100% of plant protection with 0.14 and 0.20 of relative treatment effects for disease severity in 26-day-old Chinese mustard grown in soil. The results presented here are potentially useful for advancing research on the medicinal properties, production and conservation of orchid in diverse ecosystems. Moreover, endomycorrhizal Rhizoctonia may have the potential for biological control, and that isolates of AG-P successfully controlled the damping-off of Chinese mustard.

碩士
國立臺灣大學
森林學研究所
90
The purpose of this study was to compare the influences of ecto- , endo- , and double-mycorrhizal inoculation on the growth of Eucalyptus urophylla Blake seedlings.Ectomycorrhizal mycelia of Scleroderma areolatum Her. and spores of Glomus spinosum Hu were used to inoculate to the 4-month old E.urophylla seedlings,which were cultured in the dibblings， tube containing artificial soil.One year after inoculation,comparative analysis was made among the treatments . One year after inoculation,it showed that E.urophylla seedlings could from (1) ectomycorrhizae with S. areolatum , (2) endomycorrhizae with G. spinosum, and (3) double symbioses with the former both fungi. The growth of E.urophylla seedlings was significantly stimulated (P<0.05) after being treated with mycorrhizal inoculation. In terms of height growth,the order was those inoculated with S.areolatum > S.areolatum + G.spinosum > those inoculated with G.spinosum.All inoculated seedlings were significant higher (P<0.05) than those of the uninoculated. In terms of root collar diameter,there was no significant difference (P>0.05) among all the treatments.In terms of top dry weight, the order was those inoculated with S.areolatum + G. spinosum > those inoculated with S.areolatum > those inoculated with G.spinosum > those of the uninoculated. All inoculated seedlings were significant higher (P<0.05) than those of the uninoculated. In terms of root dry weight, the order was those inoculated with S.areolatum > those inoculated with S.areolatum + G.spinosum > those inoculated with G.spinosum > those of the uninoculated. Those inoculated with S.areolatum and with the double-inoculated were significantly different (P<0.05) from those inoculated with G.spinosum only or those of the uninoculated. In terms of stem volume, the order was those inoculated with S.areolatum + G.spinosum > those inoculated with S. areolatum > those inoculated with G.spinosum > those with the uninoculated.The stem volume was significantly different (P<0.05) between those inoculated with S.areolatum,double inoculation and those with G.spinosum only or the uninoculated. T/R ratio was not significantly different among all the treatments.Mycorrhiza infection percentage formed by S. areolatum was significantly more (P<0.05) than formed by G. spinosum.Mycorrhiza infection percentage showed positive relationship (r=0.97) with seedlings height growth.

碩士
國立屏東科技大學
森林系
92
The purpose of this study were to understand which endomycorrhizal species have influenced the growth of Syzygium cumini mostly in various soil conditions. This study was separated into three parts. First, effects of different endomycorrhizal inoculation on the colonization and growth of Syzygium cumini seedlings, grown in acid red soil of Laopi series. Second, effects of different mycorrhizal inoculation on the growth of Syzygium cumini seedlings grown in two different soil media, include acid red soil of Laopi series and coastal sandsoils of southern Taiwan. Finally, effects of different mycorrhizal inoculation on the growth of Syzygium cumini seedlings grown in different pH soils amendment with lime. The results of this study showed that tree height, diameter at root collar and dry weight of root, stem and leaf have increased significantly than those noninoculanted plant. In acid red soil of Laopi series, inoculation of Glomus spp. particularly G. aggregatum, G. etunicatum and G. mosseae were the best helpful for the growth performance, especially on the increase of phosphate absorption and biomass of Syzygium cumini seedlings. Under the different soil media in acid red soil of Laopi series and coastal sand soils of southern Taiwan, the results showed endomycorrhizal inoculation contribute the better growth of Syzygium cumini under the coastal sand soils. Using different amount of limes to adjust soils pH in acid red soil of Laopi series, the biomass of the control were not increased following the increasing pH. Contrarily, the plant biomass and nutrient contents of the mycorrhizal inoculation increased follow increasing pH. The effect of endomycorrhizae inoculation on the absorption of phosphorus were different according to the efficiency of endomycorrhizal species. Generally, the plants with inoculation of Glomus spp. had higher content of phosphorous.

碩士
國立屏東科技大學
森林系
90
This study was to investigate two different soil substrates that were mixture of forest soil, peat and vermiculite and forest soil as growing medium for raising Calocedrus macrolepis var. formosana seedlings. The soil substrates used in this experiment was divided two parts, sterilized and unsterilized. The inoculation methods of each soil treatment contained control, inoculated mixed mycorrhizal fungi (Gigasspora gigantea and Acaulospora scrobiculata), inoculated Glomus intraradices , inoculated Glomus etunicatum and amended with phosphorous fertilizer. The objectives of this study were to investigate: (1) the root morphology between mycorrhizal fungi and seedling roots under light and scanning electron microscopes, (2) comparison of infection rate and mycorrhizal dependency of seedlings in various treatments, (3) effects of growth in the height and root collar diameter of Calocedrus macrolepis var. formosana seedlings in various treatments, (4) effects of the biomass of Calocedrus macrolepis var. formosana seedlings in various treatments, (5) comparisons of nutrient content of seedlings tissue in various treatments. The results of this study show that the vesical, intra hyphae and arbusicles are present in the mycorrhizal roots under the light and scanning electron microscope. These characteristics formed in the roots are the evidence of symbiotic relationship between three mycorrhizal fungi species and Calocedrus macrolepis var. formosana. All the soils of mixture substrate and forest soils, sterilized and not, inoculation of various mycorrhizal fungi had significant effects on the seedling’s growth of Calocedrus macrolepis var. formosana. The effects of inoculation with Glomus intraradices on seedling growth show best response among the mixed mycorrhizal fungi (Gigaspora gigantea and Acaulospora and scrobiculata ) and Glomus etunicatum. In conclusion, inoculation with endomycorrhizal fungi in cultivation of Calocedrus macrolepis var. formosana have the potential to enhance seedling growth.