scholarly journals Evolution of Autonomous Selfing in Marginal Habitats: Spatiotemporal Variation in the Floral Traits of the Distylous Primula wannanensis

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Zhang ◽  
Ying Feng Hu ◽  
Xiao He ◽  
Wei Zhou ◽  
Jian Wen Shao
Keyword(s):  
Seed Set ◽  
Empirical Support ◽  
Corolla Tube ◽  
Floral Traits ◽  
Tube Length ◽  
Peripheral Populations ◽  
Reproductive Assurance ◽  
Marginal Populations ◽  
Pollinator Service ◽  
Marginal Habitats

Outcrossing plant species are more likely to exhibit autonomous selfing in marginal habitats to ensure reproduction under conditions of limited pollinator and/or mate availability. Distyly is a classical paradigm that promotes outcrossing; however, little is known about the variation in floral traits associated with distylous syndrome in marginal populations. In this study, we compared the variation in floral traits including stigma and anther height, corolla tube length, herkogamy, and corolla diameter between the central and peripheral populations of the distylous Primula wannanensis, and assessed the variation of floral traits at early and late florescence stages for each population. To evaluate the potential consequences of the variation in floral traits on the mating system, we investigated seed set in each population under both open-pollinated and pollinator-excluded conditions. The flower size of both short- and long-styled morphs was significantly reduced in late-opening flowers compared with early opening flowers in both central and peripheral populations. Sex-organ reciprocity was perfect in early opening flowers; however, it was largely weakened in the late-opening flowers of peripheral populations compared with central populations. Of these flowers, disproportionate change in stigma height (elongated in S-morph and shortened in L-morph) was the main cause of reduced herkogamy, and seed set was fairly high under pollinator-excluded condition. Our results provide empirical support for the hypothesis on the evolution of delayed autonomous selfing in marginal populations of distylous species. Unsatisfactory pollinator service is likely to have promoted reproductive assurance of distylous plants with largely reduced herkogamy mimicking “homostyles.”

Morph-specific correlations between floral traits in a distylous Ophiorrhiza napoensis (Rubiaceae) population in southern China

2001 ◽  
Vol 17 (5) ◽  
pp. 719-728 ◽  
Author(s):  
HIROSHI KUDOH ◽  
TAKASHI SUGAWARA ◽  
SUGONG WU ◽  
JIN MURATA
Keyword(s):  
Southern China ◽  
Principal Component ◽  
Corolla Tube ◽  
Floral Traits ◽  
Evergreen Forest ◽  
Tube Length ◽  
Multiple Traits ◽  
Floral Trait ◽  
Subtropical Evergreen Forest ◽  
Positive Correlations

Floral trait correlations were compared between the two flower morphs of a distylous Ophiorrhiza napoensis population in a subtropical evergreen forest at the Defu Natural Animal Preserve, Guangxi, China. Common principal component analyses indicated that overall patterns in correlations among floral traits were morph specific in the study population. Strong positive correlations (r > 0.9) between anther height and corolla-tube length were found in both morphs. Stigma height correlated positively with corolla-tube length in the long-styled morph (r = 0.843), but not in the short-styled morph (r = −0.018). Flower-morph-specific correlation suggests that natural selection by pollinators has moulded trait covariance among floral traits. Because morph-specific correlations are expressed as the patterns of within-morph variation among multiple traits, putative genes responsible for the stigma-corolla tube correlation should not link to the supergene for sex-organ reciprocity between the morphs, but their expression is limited in the long-styled morph.

Study on floral traits and seed setting in parental lines of hybrid rice during early ahu and kharif seasons

2018 ◽  
Vol 78 (3) ◽  
Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka
Keyword(s):  
Seed Set ◽  
Flag Leaf ◽  
Pollen Dispersal ◽  
Pollen Sterility ◽  
Leaf Length ◽  
Floral Traits ◽  
Opening Angle ◽  
Leaf Angle ◽  
Seed Setting ◽  
Parental Lines

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.

scholarly journals Overcoming Pre-Fertilization Barriers in Intertribal Crosses between Anemone coronaria L. and Ranunculus asiaticus L.

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 529
Author(s):  
Emmy Dhooghe ◽  
Dirk Reheul ◽  
Marie-Christine Van Labeke
Keyword(s):  
Pollen Tube ◽  
Seed Set ◽  
Sperm Nucleus ◽  
Tube Length ◽  
Egg Cell ◽  
Dichlorophenoxyacetic Acid ◽  
Style Length ◽  
Ranunculus Asiaticus ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Pollen Tube Length

Hybridization in flowering plants depends, in the first place, on the delivery of pollen to a receptive stigma and the subsequent growth of pollen tubes through the style to the ovary, where the sperm nucleus of the pollen grain can ultimately fertilize the egg cell. However, reproductive failure is often observed in distant crosses and is caused by pre- and/or post-zygotic barriers. In this study, the reproductive pre-fertilization barriers of intertribal crosses between Anemone coronaria L. and Ranunculus asiaticus L., both belonging to the Ranunculaceae, were investigated. Despite the incongruity of intertribal crosses between A. coronaria and R. asiaticus having been of low intensity at the stigmatic level, interstylar obstructions of the pollen tube growth occurred, which confirmed the presence of pre-fertilization barriers. We show that these barriers could be partially bypassed by combining pollination with a stigma treatment. More specifically, a significantly higher ratio of the pollen tube length to the total style length and a better seed set were observed when the stigma was treated with the auxin 2,4-dichlorophenoxyacetic acid (2,4-D, 1 mg.mL−1) together with the cytokinin kinetin (KIN, 0.5 mg.mL−1) 24 h after pollination, irrespective of the cross direction. More specifically, the stigma treatments with any form of auxin (combined or not combined with cytokinin) resulted in a full seed set, assuming an apomictic fruit set, because no pollination was needed to obtain these seeds.

scholarly journals Butter fly Feeding Preferences of Lantana camara Cultivars and Lantana montevidensis ‘Weeping Lavender’ in the Landscape and Nectar Characteristics

2008 ◽  
Vol 26 (1) ◽  
pp. 9-18
Author(s):  
Laura L. Bruner ◽  
Donald J. Eakes ◽  
Gary J. Keever ◽  
James W. Baier ◽  
Celia Stuart Whitman ◽  
...  
Keyword(s):  
Growth Index ◽  
Flower Color ◽  
Corolla Tube ◽  
Lantana Camara ◽  
Cultivar Differences ◽  
Tube Length ◽  
Butterfly Species ◽  
Nectar Production ◽  
Design Data ◽  
Nectar Volume

Abstract In landscape studies conducted in 2002 and 2003, Lantana camara (L.) ‘New Gold’ and ‘Radiation’ were visited by native butterflies to a greater extent than the remaining eight lantana in the studies. Other lantana visited preferentially but not as consistently included L. camara ‘White Doves’, ‘Firewagon’, ‘Confetti’, and Lantana montevidensis (Spreng.) ‘Weeping Lavender’. In general, the lowest visitation was experienced by L. camara ‘Cherry’ and ‘Carlos’. Total visit duration by one randomly selected butterfly was greater for ‘New Gold’, ‘Radiation’, ‘Firewagon’, and ‘White Doves’ than the remaining lantana. Plant characteristics including inflorescence number, number of flowers per inflorescence, percentage of yellow flowers per inflorescence, growth index, flower morphology, and flower color characteristics differed among cultivars. Cultivar differences that consistently correlated with visitation preferences were inflorescence number in 2002 and 2003, flower number per inflorescence in 2003, percentage of yellow flowers per inflorescence in 2002 and 2003, and growth index in 2003. Flower lightness and flower chroma correlated sporadically with visitation in late September and October 2002 and 2003. Percentage light reflectance of flowers for the wavelengths of green, yellow, orange, and red correlated with visitation in 2003. Based on correlation analysis, the cultivar characteristics that did not contribute to visitation differences included inflorescence width, corolla width, and corolla tube length. In a separate study conducted in 2003 using the same lantana as in the visitation study, nectar volume, carbohydrate composition, and sucrose and fructose concentrations differed among inflorescences. Of ten Lantana evaluated, ‘Carlos’ and ‘Confetti had the largest inflorescence nectar volumes combined from nine flowers while ‘New Gold’, ‘White Doves’, and ‘Weeping Lavender’ had the smallest. The ratio of sucrose to hexose (fructose and glucose) in nectar from ‘Weeping Lavender’, ‘White Doves’, and ‘New Gold’ was greater than that of the remaining Lantana. The lowest ratios of sucrose to hexose were found for ‘Irene’, ‘Hot Country’, and ‘Carlos’, while similar to ‘Cherry’ and ‘Radiation’. The sucrose to hexose ratio for recently opened inner flowers was double that of middle and outer flowers. Sucrose and total sugar concentrations were greatest in recently opened inner flowers compared to middle and outer flowers. While direct comparison to the 2002 and 2003 studies of butterfly visitation preferences was not possible due to experimental design, data trends suggest a possible relationship between sugar composition, inflorescence nectar production and visitation from native butterfly species.

Buzz pollination in the Epacridaceae

2002 ◽  
Vol 50 (1) ◽  
pp. 83 ◽  
Author(s):  
T. F. Houston ◽  
P. G. Ladd
Keyword(s):  
Seed Set ◽  
Corolla Tube ◽  
Pollen Tubes ◽  
Pollination Syndrome ◽  
Native Bees ◽  
Buzz Pollination ◽  
The Family

Conostephium (Epacridaceae) has flowers that conform with a buzz-pollination syndrome but, unlike most plants with this form of pollination, the anthers are hidden within the corolla tube. Vibrations generated by bees grasping the apices of the corolla tubes must be transferred via short broad filaments to the anthers. The anthers do not have pores but each dehisces from the apex by a slit that elongates over the time the flowers take to senesce (up to 10 days). This may limit self-fertilisation as the stigma is receptive as soon as it appears from between the very short corolla lobes, so little pollen is released at first but later this would increase as the slit elongates. Visitation by pollinators has rarely been seen but several observations of native bees (Leioproctus and Lasioglossum) working the flowers are presented. The bees visit the nectarless flowers of Conostephium only for pollen and must forage at other kinds of flowers to obtain nectar. Pollen tubes occurred in the stigmas of most older flowers of C. pendulum, so pollen delivery does not seem to limit seed set. Despite this, the species sets few fruit. From examination of the taxonomic positions of likely buzz-pollinated taxa in the family, it appears that pollination by sonication has arisen independently several times in the Epacridaceae, with primarily two different floral configurations.

Corolla Tube Length Studies in Red Clover 1

1950 ◽  
Vol 42 (1) ◽  
pp. 1-8 ◽  
Author(s):  
T. M. Starling ◽  
C. P. Wilsie ◽  
N. W. Gilbert
Keyword(s):  
Red Clover ◽  
Corolla Tube ◽  
Tube Length

scholarly journals Geographical Gradients of Genetic Diversity and Differentiation among the Southernmost Marginal Populations of Abies sachalinensis Revealed by EST-SSR Polymorphism

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 233 ◽  
Author(s):  
Keiko Kitamura ◽  
Kentaro Uchiyama ◽  
Saneyoshi Ueno ◽  
Wataru Ishizuka ◽  
Ikutaro Tsuyama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Local Population ◽  
Distribution Center ◽  
Population History ◽  
Peripheral Populations ◽  
Abies Sachalinensis ◽  
Marginal Populations ◽  
Local Populations ◽  
Longitudinal Gradients

Research Highlights: We detected the longitudinal gradients of genetic diversity parameters, such as the number of alleles, effective number of alleles, heterozygosity, and inbreeding coefficient, and found that these might be attributable to climatic conditions, such as temperature and snow depth. Background and Objectives: Genetic diversity among local populations of a plant species at its distributional margin has long been of interest in ecological genetics. Populations at the distribution center grow well in favorable conditions, but those at the range margins are exposed to unfavorable environments, and the environmental conditions at establishment sites might reflect the genetic diversity of local populations. This is known as the central-marginal hypothesis in which marginal populations show lower genetic variation and higher differentiation than in central populations. In addition, genetic variation in a local population is influenced by phylogenetic constraints and the population history of selection under environmental constraints. In this study, we investigated this hypothesis in relation to Abies sachalinensis, a major conifer species in Hokkaido. Materials and Methods: A total of 1189 trees from 25 natural populations were analyzed using 19 EST-SSR loci. Results: The eastern populations, namely, those in the species distribution center, showed greater genetic diversity than did the western peripheral populations. Another important finding is that the southwestern marginal populations were genetically differentiated from the other populations. Conclusions: These differences might be due to genetic drift in the small and isolated populations at the range margin. Therefore, our results indicated that the central-marginal hypothesis held true for the southernmost A. sachalinensis populations in Hokkaido.

scholarly journals Isolation and Lack of Potential Mates may Threaten an Endangered Arid-Zone Acacia

2019 ◽  
Vol 110 (6) ◽  
pp. 738-745
Author(s):  
Cairo N Forrest ◽  
David G Roberts ◽  
Andrew J Denham ◽  
David J Ayre
Keyword(s):  
Reproductive Success ◽  
Seed Set ◽  
Arid Zone ◽  
Genotypic Diversity ◽  
Geographic Range ◽  
Landscape Scale ◽  
Reproductive Assurance ◽  
Threatened Plants ◽  
Self Fertilization ◽  
Adult Plants

Abstract Clonality may provide reproductive assurance for many threatened plants while limiting sexual reproductive success either through energetic tradeoffs or because clones are self-incompatible. Most stands of the Australian arid-zone plant Acacia carneorum, flower annually but low seed set and an absence of sexual recruitment now suggest that this species and other, important arid-zone ecosystem engineers may have low genotypic diversity. Indeed, our recent landscape-scale genetic study revealed that stands are typically monoclonal, with genets usually separated by kilometers. An inability to set sexually produced seed or a lack of genetically diverse mates may explain almost system-wide reproductive failure. Here, using microsatellite markers, we genotyped 100 seeds from a rare fruiting stand (Middle-Camp), together with all adult plants within it and its 4 neighboring stands (up to 5 km distant). As expected, all stands surveyed were monoclonal. However, the Middle-Camp seeds were generated sexually. Comparing seed genotypes with the single Middle-Camp genotype and those of genets from neighboring and other regional stands (n = 26), revealed that 73 seeds were sired by the Middle-Camp genet. Within these Middle-Camp seeds we detected 19 genotypes in proportions consistent with self-fertilization of that genet. For the remaining 27 seeds, comprising 8 different genotypes, paternity was assigned to the nearest neighboring stands Mallee and Mallee-West, approximately 1 km distant. Ironically, given this species’ vast geographic range, a small number of stands with reproductively compatible near neighbors may provide the only sources of novel genotypes.

Variation in morphology of Teucrium polium aggr. populations in Bulgaria

2010 ◽  
Vol 5 (6) ◽  
pp. 880-887 ◽  
Author(s):  
Dolja Pavlova ◽  
Magdalena Vasileva
Keyword(s):  
Corolla Tube ◽  
Leaf Length ◽  
Tube Length ◽  
Serpentine Soils ◽  
Stem Height ◽  
Multivariate Statistical ◽  
Discriminant Ability ◽  
Character Variation ◽  
Teucrium Polium ◽  
Vegetative Characters

AbstractThe aim of this study was to investigate natural serpentine and non-serpentine populations of Teucrium polium aggr. and to document the differences in their morphological traits, as well as estimate which characters are most likely contributing to differentiation of the populations. Nine populations distributed both on and off serpentine soils were investigated, and 12 different morphological features of 270 individuals were studied by univariate and multivariate statistical analyses. The results did not demonstrate clear delimitation of the serpentine from the non-serpentine populations. Using these ecotypes as classification factors in the discriminant analysis, it can be stated that stem height, leaf length in the fifth leaf pair, internode length between the fourth and the fifth leaf pairs, and corolla tube length are features with the greatest discriminant ability. The character variation was generally higher for the vegetative features, while reproductive features failed to demonstrate clear differences. The similarity groupings indicated by the cluster analysis were synchronous with groups distinguished by both the discriminant and PCA analyses. Significant differences were observed between sets of vegetative characters in all populations investigated.

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