Articles de revues : « Floral zygomorphy »

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Decraene, L. P. Ronse, E. F. Smets et D. Clinckemaillie. « The floral development and floral anatomy of Coris monspeliensis ». Canadian Journal of Botany 73, n^o 11 (1 novembre 1995) : 1687–98. http://dx.doi.org/10.1139/b95-183.

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The floral development of Coris was investigated to clarify its controversial relationship with either Primulaceae (Primulales) or Lythraceae (Myrtales). We demonstrate that Coris is strongly related to the Primulaceae but differs in a few important features, such as the presence of an epicalyx and partial zygomorphy. The saccate calyx and epicalyx with unilateral development encloses an actinomorphic flower. The stamen–petal tube has two sections that arise through three growth processes: a lower common part for stamens and petals and an upper section representing a fused corolla. The central ovule-bearing part of the ovary arises separated from the carpel wall. The formation of ridges with teethlike appendages between the ovules suggests a derivation of the free-central placentation from an axile arrangement. Several characters support the monotypic family Coridaceae near the Primulaceae. Key words: Coridaceae, Primulaceae, Lythraceae, floral development, floral vasculature, epicalyx, free-central placentation, common primordium, zygomorphy.

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Yoder, Jeremy B., Giancarlo Gomez et Colin J. Carlson. « Zygomorphic flowers have fewer potential pollinator species ». Biology Letters 16, n^o 9 (septembre 2020) : 20200307. http://dx.doi.org/10.1098/rsbl.2020.0307.

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Botanists have long identified bilaterally symmetrical (zygomorphic) flowers with more specialized pollination interactions than radially symmetrical (actinomorphic) flowers. Zygomorphic flowers facilitate more precise contact with pollinators, guide pollinator behaviour and exclude less effective pollinators. However, whether zygomorphic flowers are actually visited by a smaller subset of available pollinator species has not been broadly evaluated. We compiled 53 609 floral visitation records in 159 communities and classified the plants' floral symmetry. Globally and within individual communities, plants with zygomorphic flowers are indeed visited by fewer species. At the same time, zygomorphic flowers share a somewhat larger proportion of their visitor species with other co-occurring plants and have particularly high sharing with co-occurring plants that also have zygomorphic flowers. Visitation sub-networks for zygomorphic species also show differences that may arise from reduced visitor diversity, including greater connectance, greater web asymmetry and lower coextinction robustness of both plants and visitor species—but these changes do not necessarily translate to whole plant-visitor communities. These results provide context for widely documented associations between zygomorphy and diversification and imply that species with zygomorphic flowers may face a greater risk of extinction due to pollinator loss.

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Cubas, Pilar. « Floral zygomorphy, the recurring evolution of a successful trait ». BioEssays 26, n^o 11 (2004) : 1175–84. http://dx.doi.org/10.1002/bies.20119.

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Wang, Z., Y. Luo, X. Li, L. Wang, S. Xu, J. Yang, L. Weng et al. « Genetic control of floral zygomorphy in pea (Pisum sativum L.) ». Proceedings of the National Academy of Sciences 105, n^o 30 (23 juillet 2008) : 10414–19. http://dx.doi.org/10.1073/pnas.0803291105.

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Yuan, Zheng, Shan Gao, Da-Wei Xue, Da Luo, Lan-Tian Li, Shu-Yan Ding, Xuan Yao, Zoe A. Wilson, Qian Qian et Da-Bing Zhang. « RETARDED PALEA1 Controls Palea Development and Floral Zygomorphy in Rice ». Plant Physiology 149, n^o 1 (24 octobre 2008) : 235–44. http://dx.doi.org/10.1104/pp.108.128231.

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Zhang, Jingbo, Peter F. Stevens et Wenheng Zhang. « Evolution of floral zygomorphy in androecium and corolla in Solanaceae ». Journal of Systematics and Evolution 55, n^o 6 (19 septembre 2017) : 581–90. http://dx.doi.org/10.1111/jse.12275.

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Feng, X., Z. Zhao, Z. Tian, S. Xu, Y. Luo, Z. Cai, Y. Wang et al. « Control of petal shape and floral zygomorphy in Lotus japonicus ». Proceedings of the National Academy of Sciences 103, n^o 13 (20 mars 2006) : 4970–75. http://dx.doi.org/10.1073/pnas.0600681103.

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Bukhari, Ghadeer, Jingbo Zhang, Peter F. Stevens et Wenheng Zhang. « Evolution of the process underlying floral zygomorphy development in pentapetalous angiosperms ». American Journal of Botany 104, n^o 12 (décembre 2017) : 1846–56. http://dx.doi.org/10.3732/ajb.1700229.

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Mach, Jennifer. « Transcription Factors and Darwin's “Abominable Mystery” : Positive Autoregulation in Floral Zygomorphy ». Plant Cell 24, n^o 5 (mai 2012) : 1712. http://dx.doi.org/10.1105/tpc.112.240513.

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Kampny, Christine M., et Judith M. Canne-Hilliker. « Patterns of floral development in Agalinis and allies (Scrophulariaceae). I. Floral development of Agalinis fasciculata and A. tenuifolia ». Canadian Journal of Botany 65, n^o 11 (1 novembre 1987) : 2255–62. http://dx.doi.org/10.1139/b87-307.

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The sequence of events and morphology of structures were similar during early floral development of Agalinis tenuifolia and A. fasciculata. The lateral-posterior calyx primordia were initiated first, followed by the middle-posterior primordium, and lastly by the two anterior primordia. The corolla primordia arose in an anterior to posterior succession, then the four stamen primordia were initiated simultaneously. Later the gynoecium originated as an oval-shaped ridge. Two depressions within it became locules, and the two sides of the cleaved ridge separating them met and formed a septum. A placenta formed in each locule and numerous ovules were initiated on it. Zygomorphy was apparent in the calyx, corolla, and androecium during the primordial stage. Organogenesis in the calyx was rapid so that the calyx lobes and tube were well formed before organogenesis of other floral parts. Except for those of the calyx, floral character states distinctive for each species were manifested late in development of the floral bud.

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Hoshino, Yoichiro, Toshiya Igarashi, Masumi Ohshima, Koichi Shinoda, Naho Murata, Akira Kanno et Masaru Nakano. « Characterization of CYCLOIDEA-like genes in controlling floral zygomorphy in the monocotyledon Alstroemeria ». Scientia Horticulturae 169 (avril 2014) : 6–13. http://dx.doi.org/10.1016/j.scienta.2014.01.046.

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Nuraliev, Maxim, Dmitry Sokoloff, Polina Karpunina et Alexei Oskolski. « Patterns of Diversity of Floral Symmetry in Angiosperms : A Case Study of the Order Apiales ». Symmetry 11, n^o 4 (3 avril 2019) : 473. http://dx.doi.org/10.3390/sym11040473.

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Floral symmetry is widely known as one of the most important structural traits of reproductive organs in angiosperms. It is tightly related to the shape and arrangement of floral parts, and at the same time, it plays a key role in general appearance (visual gestalt) of a flower, which is especially important for the interactions of zoophilous flowers with their pollinators. The traditional classification of floral symmetry divides nearly all the diversity of angiosperm flowers into actinomorphic and zygomorphic ones. Within this system, which is useful for ecological studies, many variations of symmetry appear to be disregarded. At the same time, the diversity of floral symmetry is underpinned not only by ecological factors, but also by morphogenetic mechanisms and constraints. Sometimes it is not an easy task to uncover the adaptive or developmental significance of a change of the floral symmetry in a particular lineage. Using the asterid order Apiales as a model group, we demonstrate that such changes can correlate with the merism of the entire flower or of its particular whorl, with the relative orientation of gynoecium to the rest of the flower, with the presence of sterile floral elements and other morphological characters. Besides, in some taxa, the shape and symmetry of the flower change in the course of its development, which should be taken in consideration in morphological comparisons and evaluations of synapomorphies in a particular clade. Finally, we show that different results can be obtained due to employment of different approaches: for instance, many flowers that are traditionally described as actinomorphic turn out to be disymmetric, monosymmetric, or asymmetric from a more detailed look. The traditional method of division into actinomorphy and zygomorphy deals with the general appearance of a flower, and mainly considers the shape of the corolla, while the geometrical approach handles the entire three-dimensional structure of the flower, and provides an exact number of its symmetry planes.

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Knapp, Sandra. « On ‘various contrivances’ : pollination, phylogeny and flower form in the Solanaceae ». Philosophical Transactions of the Royal Society B : Biological Sciences 365, n^o 1539 (12 février 2010) : 449–60. http://dx.doi.org/10.1098/rstb.2009.0236.

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Members of the euasterid angiosperm family Solanaceae have been characterized as remarkably diverse in terms of flower morphology and pollinator type. In order to test the relative contribution of phylogeny to the pattern of distribution of floral characters related to pollination, flower form and pollinators have been mapped onto a molecular phylogeny of the family. Bilateral flower symmetry (zygomorphy) is prevalent in the basal grades of the family, and more derived clades have flowers that are largely radially symmetric, with some parallel evolution of floral bilateralism. Pollinator types (‘syndromes’) are extremely homoplastic in the family, but members of subfamily Solanoideae are exceptional in being largely bee pollinated. Pollinator relationships in those genera where they have been investigated more fully are not as specific as flower morphology and the classical pollinator syndrome models might suggest, and more detailed studies in some particularly variable genera, such as Iochroma and Nicotiana , are key to understanding the role of pollinators in floral evolution and adaptive radiation in the family. More studies of pollinators in the field are a priority.

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Zhang, W., E. M. Kramer et C. C. Davis. « Floral symmetry genes and the origin and maintenance of zygomorphy in a plant-pollinator mutualism ». Proceedings of the National Academy of Sciences 107, n^o 14 (2 avril 2010) : 6388–93. http://dx.doi.org/10.1073/pnas.0910155107.

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Liu, Jing, Juan-Juan Wang, Jie Wu, Yang Wang, Qi Liu, Fang-Pu Liu, Xia Yang et Yin-Zheng Wang. « An Optimized Transformation System and Functional Test of CYC-Like TCP Gene CpCYC in Chirita pumila (Gesneriaceae) ». International Journal of Molecular Sciences 22, n^o 9 (27 avril 2021) : 4544. http://dx.doi.org/10.3390/ijms22094544.

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The development of an ideal model plant located at a key phylogenetic node is critically important to advance functional and regulatory studies of key regulatory genes in the evolutionary developmental (evo-devo) biology field. In this study, we selected Chirita pumila in the family Gesneriaceae, a basal group in Lamiales, as a model plant to optimize its genetic transformation system established previously by us through investigating a series of factors and further conduct functional test of the CYC-like floral symmetry gene CpCYC. By transforming a RNAi:CpCYC vector, we successfully achieved the desired phenotypes of upright actinomorphic flowers, which suggest that CpCYC actually determines the establishment of floral zygomorphy and the horizontal orientation of flowers in C. pumila. We also confirmed the activities of CpCYC promoter in dorsal petals, dorsal/lateral staminodes, as well as the pedicel by transferring a CpCYC promoter:GUS vector into C. pumila. Furthermore, we testified the availability of a transient gene expression system using C. pumila mesophyll protoplasts. The improved transformation system together with the inherent biological features would make C. pumila an attractive new model in functional and regulatory studies for a broad range of evo-devo issues.

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RUDALL, PAULA J., et RICHARD M. BATEMAN. « Roles of synorganisation, zygomorphy and heterotopy in floral evolution : the gynostemium and labellum of orchids and other lilioid monocots ». Biological Reviews of the Cambridge Philosophical Society 77, n^o 3 (août 2002) : 403–41. http://dx.doi.org/10.1017/s1464793102005936.

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Yang, Xia, Hong-Bo Pang, Bo-Ling Liu, Zhi-Jing Qiu, Qiu Gao, Lai Wei, Yang Dong et Yin-Zheng Wang. « Evolution of Double Positive Autoregulatory Feedback Loops in CYCLOIDEA2 Clade Genes Is Associated with the Origin of Floral Zygomorphy ». Plant Cell 24, n^o 5 (mai 2012) : 1834–47. http://dx.doi.org/10.1105/tpc.112.099457.

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Vincent, Coral A., et Enrico S. Coen. « A temporal and morphological framework for flower development in Antirrhinum majus ». Canadian Journal of Botany 82, n^o 5 (1 mai 2004) : 681–90. http://dx.doi.org/10.1139/b04-042.

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The entire course of flower development in Antirrhinum majus L., from initiation to maturity, is described in terms of regular time intervals. Floral meristem and bud morphology was determined by scanning electron microscopy for a sequence of 58 plastochrons. These can be grouped to define 15 stages or 7 phases of development, providing a temporal framework for gene expression and key morphological events, such as the formation of the complex corolla. The time course is also used to estimate overall growth rates of sepals and petals. Sepals initially grow at a constant rate, but growth rate gradually declines at later stages and sepal growth eventually arrests before flower development is complete. Petals initially grow at a similar rate to that of early sepals, but this growth rate is maintained for a longer period, accounting for the larger size of mature petals relative to sepals. Comparisons with Arabidopsis indicate that the duration of growth also makes an important contribution to variation in flower size.Key words: Antirrhinum, flower development, meristems, zygomorphy, developmental timing, petal.

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Zhou, Xiu-Ren, Yin-Zheng Wang, James F. Smith et Rujin Chen. « Altered expression patterns of TCP and MYB genes relating to the floral developmental transition from initial zygomorphy to actinomorphy inBournea(Gesneriaceae) ». New Phytologist 178, n^o 3 (mai 2008) : 532–43. http://dx.doi.org/10.1111/j.1469-8137.2008.02384.x.

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Berti, Fabio, Marco Fambrini, Maurizio Turi, Daniele Bertini et Claudio Pugliesi. « Mutations of corolla symmetry affect carpel and stamen development in Helianthus annuus ». Canadian Journal of Botany 83, n^o 8 (1 août 2005) : 1065–72. http://dx.doi.org/10.1139/b05-047.

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The inflorescence of sunflower (Helianthus annuus L.) is heterogamous with zygomorphic ray flowers located in the outermost whorl of the head and actinomorphic disk flowers arrayed in arcs radiating from the center of the head. Two mutants with altered corolla symmetry have been described. The Chrysanthemoides (Chry) mutant is characterized by a shift from the polysymmetric corolla of disk flowers into a monosymmetric ray-like corolla. The tubular ray flower (turf) mutant is characterized by a shift from the zygomorphic corolla of ray flowers into a nearly actinomorphic tubular-like corolla. We performed a genetic analysis of turf, showing that a single nuclear recessive gene controls the trait. Furthermore, we characterized in detail the morphological floral features of Chry and turf, demonstrating that both mutations also affect the development of stamens and carpels. Most disk flowers found in the peripheral whorls of Chry heads showed drastic reduction in stamen length, as well as absence of ovules, and developed an unbranched style. By contrast, tubular-like ray flowers of turf achieved the ability to differentiate both fertile stamens and ovules. Homeotic transformations were also identified in the tubular-like ray flowers of turf, affecting both filaments and anthers that displayed petaloid-like traits. Our results point to a primary role for TURF and CHRY in the programming of the corolla symmetry and suggest a key interaction of both genes with floral organ identity genes.Key words: Helianthus annuus, floral symmetry, floral mutants, actinomorphic flowers, zygomorphic flowers.

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Pan, Bo, Guang-Da Tang, Truong Van Do, Stephen Maciejewski, Chong-Lang Deng et Fang Wen. « Oreocharis tetrapterus (Gesneriaceae), a new species from East Guangxi, China ». PhytoKeys 131 (13 septembre 2019) : 83–89. http://dx.doi.org/10.3897/phytokeys.131.35434.

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A new species, Oreocharis tetrapterus F.Wen, B.Pan & T.V.Do (Gesneriaceae) from Gupo Mountain area, Hezhou city, Guangxi Zhuangzu Autonomous Region, China, is described and illustrated. The new species has a zygomorphic tetramerous corolla with two adaxial and two abaxial lobes and two fertile stamens in the posterior position, making this a unique combination of floral characteristics in the expanded Oreocharis.

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Naghiloo, Somayeh, et Mohammad Reza Dadpour. « Floral ontogeny in Wisteria sinensis (Fabaceae : Faboideae : Millettieae) and its systematic implications ». Australian Systematic Botany 23, n^o 6 (2010) : 393. http://dx.doi.org/10.1071/sb10027.

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Floral organogenesis and development of the bushy perennial legume Wisteria sinensis (Millettieae, Fabaceae) were studied by epi-illumination light-microscopy techniques. Zygomorphic flowers of W. sinensis were arranged in alternating pentamerous whorls. The order of organogenesis in each whorl was unidirectional, except for the outer antesepalous stamens, which were initiated bidirectionally, starting on the lateral side. Unusual developmental features for the family included the formation of common primordia, comprised of the petal and the corresponding abaxial antepetalous stamen and the temporal overlap of corolla, androecium and carpel organ initiation. Unusual features during late development included formation of nectar windows and a wet stigma. The floral ontogeny of W. sinensis was more similar to that of other genera from the inverted-repeat-lacking clade (IRLC) than to the floral ontogeny of other Millettieae that have been investigated.

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Siti-Munirah, Mat Yunoh, Zainol Suhaimi-Miloko et Mohammad Ismail Zubir Ahmad. « Thismia belumensis (Thismiaceae), a remarkable new species from The Royal Belum State Park, Gerik, Perak, Peninsular Malaysia ». PhytoKeys 172 (18 février 2021) : 121–34. http://dx.doi.org/10.3897/phytokeys.172.59336.

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This report describes Thismia belumensis Siti-Munirah & Suhaimi-Miloko, a novel species of achlorophyllous herb discovered in the Royal Belum State Park, Peninsular Malaysia. This new species is unlike any previously described species of Thismia. In particular, T. belumensis possesses a unique annulus, which has been expanded and modified into a cucullate (hood-like) structure. This structure covers the apical floral tube and has an opening on one side facing a thickened part of the annulus, and the off-centre floral aperture confers a zygomorphic symmetry to the flower, indicating T. belumensis is more similar to Thismia labiata J.J.Sm. This morphological detail makes this new species distinct from all other described species of Thismia. In this report, we provide descriptions, illustrations, colour plates, and the provisional conservation status of Thismia belumensis.

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Tucker, Shirley C. « Comparative floral ontogeny in Detarieae (Leguminosae : Caesalpinioideae). 2. Zygomorphic taxa with petal and stamen suppression ». American Journal of Botany 89, n^o 6 (juin 2002) : 888–907. http://dx.doi.org/10.3732/ajb.89.6.888.

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Dadpour, Mohammad Reza, Somayeh Naghiloo et Gholamreza Gohari. « Inflorescence and floral ontogeny in Osteospermum ecklonis (Asteraceae) ». Botany 89, n^o 9 (septembre 2011) : 605–14. http://dx.doi.org/10.1139/b11-052.

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Development of the capitulum inflorescence with different types of florets in Asteraceae is an interesting issue in the field of plant evolution and development. In this study, ontogeny of the inflorescence and florets of Osteospermum ecklonis (DC.) Norl., an ornamental and evergreen subshrub, was investigated using epi-illumination light microscopy. The initiation and subsequent development of florets on the highly convex inflorescence apex occurred acropetally, except for the ray florets, which showed a lag in initiation. Organogenesis in disc florets started with unidirectional initiation of corolla lobes from the adaxial side and then proceeded by simultaneous appearance of five stamen and finally two median carpel primordia. Significant developmental features included the lack of pappus differentiation, formation of nonsyngenesious stamens, and formation of the ovule-less ovary. Ray florets showed significant differences from disc florets as reflected by the zygomorphic shape of floral apex and shift of floral merosithy from pentamery to tetramery. Also, expansion of corolla lobes to form the ligule and the formation of staminodia were observed. It is hypothesized that the actinomorphic pentamerous disc florets are most primitive among the family from which the tetramerous ray florets are derived. Accordingly, ray florets evolved from disc florets under long-term selective pressure and play a crucial role in enhancing reproductive success.

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Itagaki, Tomoyuki, Ando Misaki et Satoki Sakai. « Selection for floral integration and trait variation in zygomorphic flowers of Aconitum japonicum ssp. subcuneatum (Ranunculaceae) ». Plant Ecology 221, n^o 5 (4 mars 2020) : 347–59. http://dx.doi.org/10.1007/s11258-020-01017-0.

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He, Liang, Yawen Lei, Xin Li, Qincheng Peng, Wei Liu, Keyuan Jiao, Shihao Su, Zhubing Hu, Zhenguo Shen et Da Luo. « SYMMETRIC PETALS 1 Encodes an ALOG Domain Protein that Controls Floral Organ Internal Asymmetry in Pea (Pisum sativum L.) ». International Journal of Molecular Sciences 21, n^o 11 (5 juin 2020) : 4060. http://dx.doi.org/10.3390/ijms21114060.

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In contrast to typical radially symmetrical flowers, zygomorphic flowers, such as those produced by pea (Pisum sativum L.), have bilateral symmetry, manifesting dorsoventral (DV) and organ internal (IN) asymmetry. However, the molecular mechanism controlling IN asymmetry remains largely unclear. Here, we used a comparative mapping approach to clone SYMMETRIC PETALS 1 (SYP1), which encodes a key regulator of floral organ internal asymmetry. Phylogenetic analysis showed that SYP1 is an ortholog of Arabidopsis thaliana LIGHT-DEPENDENT SHORT HYPOCOTYL 3 (LSH3), an ALOG (Arabidopsis LSH1 and Oryza G1) family transcription factor. Genetic analysis and physical interaction assays showed that COCHLEATA (COCH, Arabidopsis BLADE-ON-PETIOLE ortholog), a known regulator of compound leaf and nodule identity in pea, is involved in organ internal asymmetry and interacts with SYP1. COCH and SYP1 had similar expression patterns and COCH and SYP1 target to the nucleus. Furthermore, our results suggested that COCH represses the 26S proteasome-mediated degradation of SYP1 and regulates its abundance. Our study suggested that the COCH-SYP1 module plays a pivotal role in floral organ internal asymmetry development in legumes.

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Souza, Vênia Camelo de, Leonaldo Alves de Andrade et Zelma Glebya Maciel Quirino. « Floral biology of Sesbania virgata : an invasive species in the Agreste of Paraíba, northeastern Brazil ». Rodriguésia 67, n^o 4 (décembre 2016) : 871–78. http://dx.doi.org/10.1590/2175-7860201667402.

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Abstract Although reproduction seems to play an important role in the successful invasive strategy of Sesbania virgata, its floral biology is poorly known. We aimed at filling this gap by studying the floral biology of a population of S. virgata in the Agreste of Brazil. Sesbania virgata is a shrub that bears racemose inflorescences. Its flowers are zygomorphic, pedunculate, hermaphrodite, and have a pale yellow corolla, diadelphous androecium, anthers with longitudinal dehiscence, and inconspicuous stigma. S. virgata flowers display three different types of petals: banner (11.92 mm), wing (8.27 mm), and keel (9.3 mm). The flowering peak occurred from November to January. The average number of pollen grains per flower was 22,918, with a pollen viability of 99.93%. Its anthesis is diurnal and asynchronous. Although S. virgata is autogamous, its pollen/ovule ratio suggests that this plant has a mixed reproductive system (xenogamy + autogamy). Continuous flowering, flower morphology, and specialized breeding system are essential to assure the reproductive success of this species in the studied habitat. Sesbania virgata is a food source for flower visitors, due to its continuous flowering and large population. Therefore, it has an effective reproductive strategy that assures its invasion success.

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Rudall, P. J., R. M. Bateman, M. F. Fay et A. Eastman. « Floral anatomy and systematics of Alliaceae with particular reference to Gilliesia, a presumed insect mimic with strongly zygomorphic flowers ». American Journal of Botany 89, n^o 12 (1 décembre 2002) : 1867–83. http://dx.doi.org/10.3732/ajb.89.12.1867.

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Mizzotti, Chiara, Marco Fambrini, Elisabetta Caporali, Simona Masiero et Claudio Pugliesi. « A CYCLOIDEA-like gene mutation in sunflower determines an unusual floret type able to produce filled achenes at the periphery of the pseudanthium ». Botany 93, n^o 3 (mars 2015) : 171–81. http://dx.doi.org/10.1139/cjb-2014-0210.

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The pseudanthium of sunflower (Helianthus annuus L.) consists of two floret types: zygomorphic sterile ray florets and actinomorphic hermaphrodite disc florets. In the tubular ray flower (turf) mutant, the loss-of-function of a CYCLOIDEA (CYC) gene generates hermaphrodite tubular-like ray florets that replace the normal sterile ray florets. We evaluated whether tubular-like ray florets have a multifaceted set of floral traits and the presence of heteromorphic seeds in the turf inflorescence. During early stages of floral ontogeny, primordia of both tubular-like ray florets and typical ray florets displayed a comparable shape. In contrast, during later stages of development, the form of tubular-like ray floret primordia was most similar to disc floret primordia. In mature tubular-like ray florets, corolla and ovary had both ray and disc floret characteristics but also displayed distinct identity traits. In open-pollinated tubular-like ray florets, the seed set was low, but a noteworthy increase of filled achenes was obtained by hand pollination. Wild type ray achenes were always empty. Embryos of tubular-like ray florets were shorter and lighter than the embryos of disc florets but able to produce fertile plants. In conclusion, the different identity characteristics combined in tubular-like ray florets of the mutant evolved a capitulum type not described in the genus Helianthus.

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Tucker, Shirley C. « Floral ontogeny of Hardenbergia violacea (Fabaceae : Faboideae : Phaseoleae) and taxa of tribes Bossiaeeae and Mirbelieae, with emphasis on presence of pseudoraceme inflorescences ». Australian Systematic Botany 19, n^o 3 (2006) : 193. http://dx.doi.org/10.1071/sb05004.

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The floral ontogeny of several Australian papilionoid taxa has been studied in Hardenbergia violacea L. (Phaseoleae); Kennedia rubicunda (Phaseoleae; inflorescences only); Bossiaea cordigera (Bossiaeeae); Gastrolobium truncatum, Mirbelia oxylobioides, and Pultenaea daphnoides (Mirbelieae). Species studied of Hardenbergia, Pultenaea, and Brachysema have pseudoracemose inflorescences comprised of triads of flowers, Kennedia rubicunda has paired flowers that resemble reduced pseudoracemes, while Gastrolobium truncatum and Mirbelia oxylobioides have pseudoracemes comprised of 2–10 flowers per ultimate unit. Pseudoracemes are a significant and overlooked feature in many taxa of tribes Bossiaeeae and Mirbelieae. Hardenbergia violacea has ultimate axillary units of three flowers, each with a subtending bract but no bracteoles. Floral ontogeny in H. violacea and P. daphnoides shows acropetal order among whorls, and unidirectional order starting from the abaxial side in sepal, petal, and stamen whorls, as in most papilionoid flowers. The carpel is initiated concurrently with the first antesepalous stamen primordium. Pultenaea daphnoides and Bossiaea cordigera have unidirectional sepal initiation starting abaxially, but simultaneous petal initiation, an unusual feature among papilionoids. In late stages of H. violacea and B. cordigera, a diadelphous stamen tube or sheath is formed, while in taxa of Mirbelieae the stamens remain free. The flowers in all taxa studied become strongly zygomorphic as evidenced by three petal morphs and upturning of the free portions of style and stamens late in development.

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Kan, Pei-Wen, Yu-Ching Cheng et Der-Ming Yeh. « Mechanism of Leaf Vein Coloration and Inheritance of Leaf Vein Color, Flower Form, and Floral Symmetry in Gloxinia ». Journal of the American Society for Horticultural Science 146, n^o 3 (mai 2021) : 178–83. http://dx.doi.org/10.21273/jashs05034-20.

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Double-flowered gloxinia (Sinningia speciosa) cultivars with foliar variegation might have a greater market appeal as flowering foliage plants. Crosses were made among 16 gloxinia cultivars and their progenies were analyzed to determine the inheritance of leaf vein color, flower form, and floral symmetry. All plants from self-pollinating white-veined cultivars or crosses between white-veined and green-veined cultivars produced white veins. Progeny derived from self-pollinating plants of white-veined cultivars × green-veined cultivars segregated into a ratio of 3 white-veined:1 green-veined. All plants from self-pollinating or cross-pollinating single-flowered cultivars produced single flowers. Progeny of self-pollination or crosses between double-flowered cultivars segregated into a ratio of 3 double flowers:1 single flower. Contingency chi-square tests revealed that leaf vein color and flower form were inherited independently. New gloxinia progenies with homozygous white veins and double flowers were successfully developed from the F2 segregating population. Plants from self-pollinating or cross-pollinating cultivars with actinomorphic flowers produced actinomorphic flowers. A single dominant gene expressed in the homozygous or heterozygous state resulted in the zygomorphic flowers. Independent inheritance was observed between vein color and floral symmetry. Air spaces between the epidermis and the mesophyll cells were observed in the white, but not in the green, leaf vein portions. Net photosynthesis did not differ significantly between the white vein and adjacent green portion of the same leaf.

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Yang, Yi, Ming Sun, Cunquan Yuan, Yu Han, Tangchun Zheng, Tangren Cheng, Jia Wang et Qixiang Zhang. « Interactions between WUSCHEL- and CYC2-like Transcription Factors in Regulating the Development of Reproductive Organs in Chrysanthemum morifolium ». International Journal of Molecular Sciences 20, n^o 6 (14 mars 2019) : 1276. http://dx.doi.org/10.3390/ijms20061276.

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Chrysanthemum morifolium is a gynomonoecious plant that bears both female zygomorphic ray florets and bisexual actinomorphic disc florets in the inflorescence. This sexual system is quite prevalent in Asteraceae, but poorly understood. CYCLOIDEA (CYC) 2 subclade transcription factors, key regulators of flower symmetry and floret identity in Asteraceae, have also been speculated to function in reproductive organs and could be an entry point for studying gynomonoecy. However, the molecular mechanism is still unclear. On the other hand, the Arabidopsis WUSCHEL (WUS) transcription factor has been proven to play a vital role in the development of reproductive organs. Here, a WUS homologue (CmWUS) in C. morifolium was isolated and characterized. Overexpression of CmWUS in A. thaliana led to shorter siliques and fewer stamens, which was similar to CYC2-like genes reported before. In addition, both CmWUS and CmCYC2 were highly expressed in flower buds during floral organ differentiation and in the reproductive organs at later development stages, indicating their involvement in the development of reproductive organs. Moreover, CmWUS could directly interact with CmCYC2d. Thus, our data suggest a collaboration between CmWUS and CmCYC2 in the regulation of reproductive organ development in chrysanthemum and will contribute to a further understanding of the gynomonoecious sexual system in Asteraceae.

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Bizecki Robson, Diana, Cary Hamel, Rebekah Neufeld et Barbara I. Bleho. « Habitat filtering influences plant–pollinator interactions in prairie ecosystems ». Botany 97, n^o 3 (mars 2019) : 204–20. http://dx.doi.org/10.1139/cjb-2018-0134.

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The xeric hypothesis is that bees are more abundant pollinators than anthophilous flies in dry, temperate biomes, and the habitat filtering hypothesis is that differences in the proportions will impact plant community composition because different pollinators favour different floral traits. However, few studies have examined the predictive value of these hypotheses. In particular, differences in plant–pollinator compositions within biomes, such as the Prairie Ecozone, have not been compared. We documented plant–pollinator interactions and plant abundance in three Canadian prairie types. Flower visits in moist tall grass prairie were mainly by flies in the Syrphidae, whereas visits in the drier fescue and mixed grass prairie were mainly by long-tongued bees in the Apidae. Short-tongued bee visits were not significantly different between the prairie types. Insect visits to tubular, zygomorphic, violet/blue-, and white-flowered plants were higher in drier fescue and mixed grass prairie than in moister tall grass prairie. Further, proportions of plants with these features were lower in the tall grass prairie. Thus differences in the proportion of flies and long-tongued bees, likely affected by habitat conditions including moisture levels, appear to be influencing the types of plants that dominate each prairie type, providing some support for these hypotheses.

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Cordeiro, Guaraci D., Rodolfo Liporoni, Carolina A. Caetano, Cristiane Krug, Carlos A. Martínez-Martínez, Herbeson O. J. Martins, Renan K. O. A. Cardoso et al. « Nocturnal Bees as Crop Pollinators ». Agronomy 11, n^o 5 (20 mai 2021) : 1014. http://dx.doi.org/10.3390/agronomy11051014.

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Bees are typically diurnal but around 1% of described species have nocturnal activity. Nocturnal bees are still poorly studied due to bias towards studying diurnal insects. However, knowledge concerning their biology and role as crop pollinators has increased. We review the literature on nocturnal bees’ traits and their host plants, and assess the crop pollination effectiveness of this neglected group. Nocturnal bees have visual adaptations to cope with low light intensities, and floral scents are a key sensory cue used to find their host flowers. Nocturnal bees generally show high flower constancy, the ability to vibrate flowers, and high transfer rates of pollen grains to stigmas. The flowers visited by nocturnal bees range from small radial and zygomorphic flowers to large brush blossoms; moreover, they visit plants with different flowering strategies. Nocturnal bees are effective pollinators of regional fruit crops in Brazil, such as cambuci (Campomanesia phaea), guaraná (Paullinia cupana), cajá (Spondias mombin), and in North America of cultivated pumpkins (Cucurbita species). However, they most likely are pollinators of several other crops. Strategies to host high numbers of nocturnal bees around cropping areas should be taken, such as preserving adjacent native forests, restricting soil management, providing food resources beyond crop flowers, and avoiding light pollution.

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Kamińska, Magdalena, et Małgorzata Stpiczyńska. « The structure of the spur nectary in Dendrobium finisterrae Schltr. (Dendrobiinae, Orchidaceae) ». Acta Agrobotanica 64, n^o 1 (2012) : 19–26. http://dx.doi.org/10.5586/aa.2011.003.

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To date, the structure of the nectary spur of <i>Dendrobium finisterrae</i> has not been studied in detail, and the present paper compares the structural organization of the floral nectary in this species with the spurs of other taxa. The nectary spur of <i>D. finisterrae</i> was examined by means of light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It is composed of a single layer of secretory epidermis and several layers of small and compactly arranged subepidermal secretory cells. The secretory cells have thick cellulosic cell walls with primary pits. The secretory tissue is supplied by vascular bundles that run beneath in ground parenchyma and are additionally surrounded by strands of sclerenchymatous fibers. The flowers of the investigated species displayed morphological features characteristic of bee-pollinated taxa, as they are zygomorphic, creamy-green coloured with evident nectar guides. They also emit a weak but nice scent. However, they possess some characters attributed to bird-pollinated flowers such as a short, massive nectary spur and collenchymatous secretory tissue that closely resembles the one found in the nectaries of certain species that are thought to be bird-pollinated. This similarity in anatomical organization of the nectary, regardless of geographical distribution and phylogeny, strongly indicates convergence and appears to be related to pollinator-driven selection.

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Morel, Jérémie, Jérôme Duminil et Jérôme Munzinger. « Bopopia, a new monotypic genus of Gesneriaceae (Gesnerioideae, Coronanthereae) from New Caledonia ». European Journal of Taxonomy 736 (1 mars 2021) : 82–101. http://dx.doi.org/10.5852/ejt.2021.736.1253.

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A new genus of Gesneriaceae, Bopopia Munzinger & J.R.Morel gen. nov., is described from New Caledonia. The genus is based on B. parviflora Munzinger & J.R.Morel gen. et sp. nov., a new species collected during an expedition on Mt Katalupaik, in the North Province of New Caledonia’s main island. Originally considered as a species of Coronanthera, our phylogenetic analysis – including 19 species within Coronanthereae and two individuals of B. parviflora gen. et sp. nov., and using three molecular markers (nuclear rDNA ITS, and chloroplast regions trnL-trnF and trnE-trnT) – showed that the new species is not close to Coronanthera in subtribe Coronantherinae, but belongs to subtribe Negriinae where it is sister to Depanthus. From that genus Bopopia gen. nov. differs in floral symmetry (zygomorphic vs actinomorphic) and the number of stamens (4 vs 5). From the other genera of Negriinae the new genus differs in the white corolla and its indeterminate thyrse with 3 to 5 levels of branching. The morphological circumscription of the subtribe Negriinae is amended to include Bopopia gen. nov. Two keys are provided, one to the subtribes in the tribe Coronanthereae, and one to the genera in subtribe Negriinae. Following the IUCN Red List categories and criteria, the conservation status of B. parviflora gen. et sp. nov. is provisionally assessed as Endangered (EN).

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Zhang, Wen-Gen, Yu-Guang Liu, Tang-Jie Nie, Chun-Ce Guo, Li-Hong Qiu, Guang-Yao Yang, Florian Jabbour et Wei Wang. « Floral ontogeny of Delphinium anthriscifolium (Ranunculaceae) and development of intrafloral and symmetrical resupinated organs ». Botanical Journal of the Linnean Society, 13 juillet 2021. http://dx.doi.org/10.1093/botlinnean/boab041.

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Abstract Delphinieae (Ranunculaceae) are characterized by zygomorphic spiral flowers and show a remarkable diversity of perianth organization. Floral structure and development have been investigated in most lineages of the tribe, mainly focusing on the establishment of symmetry and on perianth development. In this study, floral organogenesis and morphogenesis in Delphinium anthriscifolium, a member of the recently erected Delphinium subgenus Anthriscifolium, were investigated and compared with those of other species of Delphinieae in a phylogenetic context. In D. anthriscifolium, zygomorphy of the spiral flower is established soon after the initiation of sepal primordia. Among the four fully developed petals of the dorsoventralized corolla, the two dorsalmost ones become spurred, and the lateral petals resupinate before anthesis and are mirror images of each other. Resupination of petals, long overlooked in morphological studies of Delphinieae, is here reported in Ranunculaceae for the first time. The role of resupinated petals, possibly acting as a landing platform for nectar foragers, may be of high adaptive significance. Based on our new findings regarding floral ontogeny and morphology in D. anthriscifolium, we provide an updated picture of floral evolution in Delphinieae.

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Espinosa, Felipe, Catherine Damerval, Martine Le Guilloux, Thierry Deroin, Wei Wang, Myreya Pinedo-Castro, Sophie Nadot et Florian Jabbour. « Homeosis and delayed floral meristem termination could account for abnormal flowers in cultivars of Delphinium and Aquilegia (Ranunculaceae) ». Botanical Journal of the Linnean Society, 13 août 2020. http://dx.doi.org/10.1093/botlinnean/boaa063.

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Abstract Floral mutants display various deviant phenotypes and, as such, they are appropriate material with which to address the origin and the building of morphological variation. To identify the pivotal developmental stages at which floral variation may originate and to infer the putative associated genetic causes, we studied abnormal flowers in nine cultivars of Aquilegia and Delphinium of Ranunculaceae, a family displaying a high range of floral diversity. Wild-type flowers of the two genera are pentamerous and spurred, but they differ in their overall symmetry (actinomorphy vs. zygomorphy). Floral morphology of their cultivars at different developmental stages up to anthesis was observed, and the putative identity of the perianth organs and vascularization was inferred. Our results show that in the floral mutants in both genera, phyllotaxis was generally conserved, whereas floral organization, vascularization and symmetry were modified. Most of the morphological and anatomical deviations impacted the perianth, including organ number, identity and (spur) elaboration, and also led to the formation of mosaic organs. We hypothesized that the phenotypes of floral mutants in Aquilegia and Delphinium result from genetic alterations affecting frontiers between sets of organs of different identity, homeosis and length of floral meristem activity.

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Liu, Jing, Jie Wu, Xia Yang et Yin‐Zheng Wang. « Regulatory pathways of CYC ‐like genes in patterning floral zygomorphy exemplified in Chirita pumila ». Journal of Systematics and Evolution, 16 février 2020. http://dx.doi.org/10.1111/jse.12574.

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Mochizuki, Jun, Tomoyuki Itagaki, Yuta Aoyagi Blue, Masaya Ito et Satoki Sakai. « Ovule and seed production patterns in relation to flower size variations in actinomorphic and zygomorphic flower species ». AoB PLANTS 11, n^o 5 (1 septembre 2019). http://dx.doi.org/10.1093/aobpla/plz061.

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Abstract Zygomorphic flower species tend to show lower flower size variation than actinomorphic flower species. Have these differences also brought an association in ovule and seed production that has arisen due to natural selection in these species? Flowers were collected from 29 actinomorphic and 20 zygomorphic flower species, and fruits were collected from 21 actinomorphic and 14 zygomorphic flower species in Miyagi and Aomori prefectures, in Japan. The coefficient of variations (CVs) of flower sizes, mean ovule sizes of flowers, ovule numbers of flowers and mean seed sizes of fruits were calculated. The CV of flower sizes was marginally different between the floral symmetry types; tending to be lower in the zygomorphic flower species than in the actinomorphic flower species. The CVs of mean ovule sizes and ovule numbers of flowers increased with increase in the CV of flower sizes in the actinomorphic flower species but not in the zygomorphic flower species. Mean ovule number of flowers tends to increase with increase in mean flower size in the actinomorphic flower species but not in the zygomorphic flower species. The degrees in variations in ovule size and number of flowers were influenced by the interaction of floral symmetry type and flower size variation, suggesting that floral symmetry also has brought an evolutionary association in ovule production by flowers.

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Rios-Carrasco, Sandra, et SONIA VÁZQUEZ-SANTANA. « Comparative morphology and ontogenetic patterns of Bdallophytum species (Cytinaceae, Malvales) : insight into the biology of an endoparasitic genus ». Botany, 4 décembre 2020. http://dx.doi.org/10.1139/cjb-2020-0025.

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Cytinaceae are root endoparasitic plants with only three genera. Their biology is largely unknown, and most knowledge of the family is based on the Old World genus, Cytinus. Here, we studied all three species of the New World Bdallophytum from Mexico. We describe their morphoanatomy, floral development, and embryology, highlighting the unique traits of Bdallophytum compared with two other genera of the family and members of Malvales. Both B. americanum and B. andrieuxii are dioecious, while B. oxylepis is gynomonoecious. The floral size and the number of floral organs vary within and among species, which appears common in Cytinaceae. The flowers of Bdallophytum exhibit synorganization in sexual organs, a synandrium in male flowers, and a gynostemium in bisexual flowers of B. oxylepis. Unisexual and bisexual flowers are zygomorphic at the early developmental stages. The unisexual flowers become actinomorphic in later development, while the bisexual flowers of B. oxylepis remain zygomorphic. The androecium of Bdallophytum has key traits shared with some Malvales, such as the fused filaments in Malvaceae and Sarcolaenaceae and the connective appendage shared with Dipterocarpaceae. Our results suggest that a unitegmic ovule is a unique trait for Bdallophytum. This is proposed here as a putative synapomorphy for Bdallophytum.

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Chandra, Kailash, R. Nandini, Gobu R., Pranesh ., Chitti Bharat Kumar et R. Muthuraju. « Insight into floral biology and ancillary characteristics of underutilized legume-Bambara groundnut [Vigna subterranea (L.) Verdc.] ». LEGUME RESEARCH - AN INTERNATIONAL JOURNAL, of (26 octobre 2017). http://dx.doi.org/10.18805/lr-3811.

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The present study floral biology and ancillary characteristics of Bambara groundnut used SB-42, Uniswa Red, S-165-A, S-193 and nine isolated gamma irradiated stabilized mutants of SB-42 for this investigation. Mutant 11 produced significantly maximum number of pods per plant (46.05 g/ plant) and seed yield per plant (28.96 g/plant), compared to control SB-42 (40.85 g/plant, 20.54 g/plant) respectively. Results obtained from flower biology studies were, Inflorescence- Simple Racemes, Flower- Bracteates, Zygomorphic, Hermaphrodite, Pedicellate, hypogynous, Calyx- sepal 5, gamosepalous, valvate aestivation, Corolla- petals 5, Polypetalous, Papilionaceous with a standard (vexilum/banner) petal, 2 wing petals(Alae) and 2 keel petals (Carinea), Androecium- stamens 10, Didelphous condition (9+1), Gynoecium- Ovary superior, Floral formula- Br Brl % K(5) C1+ 2 + (2) A 9+1 G (1).

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Zhang, Wenheng, Victor W. Steinmann, Lachezar Nikolov, Elena M. Kramer et Charles C. Davis. « Divergent genetic mechanisms underlie reversals to radial floral symmetry from diverse zygomorphic flowered ancestors ». Frontiers in Plant Science 4 (2013). http://dx.doi.org/10.3389/fpls.2013.00302.

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Liu, Hua, Ming Sun, Huitang Pan, Tangren Cheng, Jia Wang et Qixiang Zhang. « Two Cyc2CL transcripts (Cyc2CL-1 and Cyc2CL-2) may play key roles in the petal and stamen development of ray florets in chrysanthemum ». BMC Plant Biology 21, n^o 1 (19 février 2021). http://dx.doi.org/10.1186/s12870-021-02884-z.

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Abstract Background Chrysanthemum morifolium is one of the most popular ornamental crops. The capitulum, which is the main ornamental part of chrysanthemum plants, consists of ligulate marginal ray florets, an attractive corolla (petals), and radially hermaphroditic disc florets, but no stamens. In Asteraceae species, the zygomorphic ray florets evolved from the actinomorphic disc florets. During this process, the zygomorphic ligulate corolla arose and the stamens were aborted. Although molecular genetic research has clarified ray floret development to some extent, the precise molecular mechanism underlying ray floret development in chrysanthemum remained unclear. Results A CYC2-like gene, Cyc2CL, was cloned from C. morifolium ‘Fenditan’. Subsequent analyses revealed that the alternative splicing of Cyc2CL, which occurred in the flower differentiation stage, resulted in the production of Cyc2CL-1 and Cyc2CL-2 in the apical buds. Prior to this stage, only Cyc2CL-1 was produced in the apical buds. A fluorescence in situ hybridization analysis of labeled Cyc2CL-1 and Cyc2CL-2 RNA indicated that Cyc2CL-2 was first expressed in the involucre tissue during the final involucre differentiation stage, but was subsequently expressed in the receptacle and floret primordia as the floral bud differentiation stage progressed. Moreover, Cyc2CL-2 was highly expressed in the inflorescence tissue during the corolla formation stage, and the expression remained high until the end of the floral bud differentiation stage. Furthermore, the overexpression of Cyc2CL-1 and Cyc2CL-2 in transgenic Arabidopsis inhibited stamen and petal development. Therefore, both Cyc2CL-1 and Cyc2CL-2 encode candidate regulators of petal development and stamen abortion and are important for the ray floret development in chrysanthemum. Conclusion In this study, we characterized the alternatively spliced transcripts of the CYC2-like gene that differ subtly regarding expression and function. The data presented herein will be useful for clarifying the regulatory mechanisms associated with the CYC2-like gene and may also be important for identifying the key genes and molecular mechanisms controlling the development of ray florets in chrysanthemum.

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Wang, Chun-Neng, Hao-Chun Hsu, Cheng-Chun Wang, Tzu-Kuei Lee et Yan-Fu Kuo. « Quantifying floral shape variation in 3D using microcomputed tomography : a case study of a hybrid line between actinomorphic and zygomorphic flowers ». Frontiers in Plant Science 6 (10 septembre 2015). http://dx.doi.org/10.3389/fpls.2015.00724.

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García Morales, Leccinum Jesús, Rodrigo Homero González González, Jesús García Jiménez et Duilio Iamonico. « A new species of Cochemiea (Cactaceae, Cacteae) from Sinaloa, Mexico ». Acta Botanica Mexicana, n^o 127 (18 février 2020). http://dx.doi.org/10.21829/abm127.2020.1626.

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Background and Aims: Cochemiea is a genus which currently comprises five species occurring in Mexico. It is morphologically characterized by cylindrical decumbent to prostrate stems and by a long red-scarlet zygomorphic perianth, presumably specialized for hummingbird pollination. As part ofthe ongoing taxonomic studies on the North Mexican flora, a population discovered by Thomas Linzen in 2012 in central Sinaloa (Mexico), previously identified as Mammillaria sp., actually refers to a Cochemiea species and cannot be ascribed to any of the known species of that genus. As a consequence,we here propose to describe this population as a a new species for science.Methods: The work is based on field surveys (autumn 2018 and spring 2019) in central Sinaloa, examination of herbarium specimens, and analysis of relevant literature. Its conservation status was assessed following the guidelines of the IUCN; AOO and EOO were calculated with the programGeoCAT.Key results: Cochemiea thomasii is described and illustrated from Sinaloa. The new species is morphologically similar to C. halei from which it differs by the hanging stems, the larger conical tubercles, less numerous and shorter central spines, and the ovoid fruits. A diagnostic key of the knownCochemiea species is included.Conclusions: Cochemiea thomasii is endemic to the state of Sinaloa where it occupies a small area. On the basis of the criteria B2a (geographic range) and C (small population) of IUCN, the new species can be assessed as Critically Endangered (CR) or Vulnerable (VU). Adopting the precautionary approach, Cochemiea thomasii is considered as Critically Endangered (CR).

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