A linear polyad: a distinctive pollen dispersal unit in Xyris complanata (Xyridaceae)

Abstract The main morphological, cytological and physiological characters of ripe pollen are described, compared, analysed and discussed individually, in multiple combinations and in respect to the female counterpart and the biotic and abiotic components of the environment. This is to try to understand the reasons why pollen grains have the same reproductive function, but at dispersal are morphologically and physiologically different in many respects. The considered characters are: one or more types of grain per species; shape and size; number of cells; types of pollen dispersal unit; sporoderm stratification, furrows, colpori and other kinds of apertures; pollen presentation and array; water content percentage; and mature pollen reserves and osmotics. Some of the pollen features are correlated between themselves, some with the female counterpart or male and female competition, and others with the different components of the environment where the species lives, when it flowers and when pollen presentation occurs.

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Accelerated diversification correlated with functional traits shapes extant diversity of the early divergent angiosperm family Annonaceae

10.1101/652065 ◽

2019 ◽

Author(s):

B. Xue ◽

X. Guo ◽

J.B. Landis ◽

M. Sun ◽

C.C. Tang ◽

...

Keyword(s):

Species Richness ◽

Method Of Moments ◽

Pollen Dispersal ◽

Sex Expression ◽

Diversification Rates ◽

Total Species Richness ◽

Dispersal Unit ◽

High Species Richness ◽

Selected Traits ◽

Method Of Moments Estimator

BackgroundA major goal of phylogenetic systematics is to understand both the patterns of diversification and the processes by which these patterns are formed. Few studies have focused on the ancient, species-rich Magnoliales clade and its diversification pattern. Within Magnoliales, the pantropically distributed Annonaceae are by far the most genus-rich and species-rich family-level clade, with c. 110 genera and c. 2,400 species. We investigated the diversification patterns across Annonaceae and identified traits that show varied associations with diversification rates using a time-calibrated phylogeny of 835 species (34.6% sampling) and 11,211 aligned bases from eight regions of the plastid genome (rbcL, matK, ndhF, psbA-trnH, trnL-F, atpB-rbcL, trnS-G, and ycf1). Two hypotheses that might explain patterns of diversification—the ‘museum model’ and heterogeneous diversification rates—are also evaluated.ResultsTwelve rate shifts were identified using BAMM: in Annona, Artabotrys, Asimina, Drepananthus, Duguetia, Goniothalamus, Guatteria, Uvaria, Xylopia, the tribes Miliuseae and Malmeeae, and the Desmos-Dasymaschalon-Friesodielsia-Monanthotaxis clade (which collectively account for over 80% of the total species richness in the family). TurboMEDUSA and method-of-moments estimator analyses showed largely congruent results. A positive relationship between species richness and diversification rate is revealed using PGLS. We further explore the possible role of selected traits (habit, pollinator trapping, floral sex expression, pollen dispersal unit, anther septation, and seed dispersal unit) in shaping diversification patterns, based on inferences of BiSSE, MuSSE, HiSSE, and FiSSE analyses. Our results suggest that the liana habit, the presence of circadian pollinator trapping, androdioecy, and the dispersal of seeds as single-seeded monocarp fragments are closely correlated with higher diversification rates; pollen aggregation and anther septation, in contrast, are associated with lower diversification rates.ConclusionOur results show that the high species richness in Annonaceae is likely the result of recent increased diversification rather than the steady accumulation of species via the ‘museum model’. BAMM, turboMEDUSA, and the method-of-moments estimator all indicate heterogeneity in diversification rates across the phylogeny, with different traits associated with shifts in diversification rates in different Annonaceae clades.

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

Indian Journal of Genetics and Plant Breeding (The) ◽

10.31742/ijgpb.78.3.2 ◽

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.

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Analysis of Genetic Structure and Dispersal Patterns in a Population of Sea Beet

Genetics ◽

10.1093/genetics/149.4.1975 ◽

1998 ◽

Vol 149 (4) ◽

pp. 1975-1985

Author(s):

Jarle Tufto ◽

Alan F Raybould ◽

Kjetil Hindar ◽

Steinar Engen

Keyword(s):

Equilibrium Distribution ◽

Pollen Dispersal ◽

Migration Pattern ◽

Likelihood Ratio Tests ◽

Frequency Data ◽

Gene Frequencies ◽

Dispersal Patterns ◽

Parametric Bootstrapping ◽

Estimated Parameters ◽

Multivariate Stochastic Process

Abstract A model of the migration pattern in a metapopulation of sea beet (Beta vulgaris L. ssp. maritima), based on the continuous distributions of seed and pollen movements, is fitted to gene frequency data at 12 isozyme and RFLP loci by maximum likelihood by using an approximation of the simultaneous equilibrium distribution of the gene frequencies generated by the underlying multivariate stochastic process of genetic drift in the population. Several alternative restrictions of the general model are fitted to the data, including the island model, a model of complete isolation, and a model in which the seed and pollen dispersal variances are equal. Several likelihood ratio tests between these alternatives are performed, and median bias in the estimated parameters is corrected by using parametric bootstrapping. To assess the fit of the selected model, the predicted covariances are compared with covariances computed from the data directly. The dependency of estimated parameters on the ratio between effective and absolute subpopulation sizes, which is treated as a known parameter in the analysis, is also examined. Finally, we note that the data also appear to contain some information about this ratio.

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Sharing the Agrarian Knowledge with Archaeology: First Evidence of the Dimorphism of Vitis Pollen from the Middle Bronze Age of N Italy (Terramara Santa Rosa di Poviglio)

Sustainability ◽

10.3390/su13042287 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2287

Author(s):

Anna Maria Mercuri ◽

Paola Torri ◽

Assunta Florenzano ◽

Eleonora Clò ◽

Marta Mariotti Lippi ◽

...

Keyword(s):

Vitis Vinifera ◽

Bronze Age ◽

Pollen Morphology ◽

Pollen Dispersal ◽

Archaeological Site ◽

Central Mediterranean ◽

Pollen Dimorphism ◽

History Of ◽

Inaperturate Pollen ◽

Female Flowers

The recovery of inaperturate pollen from functionally female flowers in archaeological layers opens the question of a possible pollen-based discrimination between wild and domesticated Vitis vinifera in prehistoric times. Pollen analysis applied to archaeology has not routinely considered the existence of pollen dimorphism in Vitis, a well-known trait in the field of agrarian studies. Therefore, the inaperturate shape of grapevine pollen is ignored by studies on the archaeobotanical history of viticulture. In this paper we investigate pollen morphology of the domesticated and wild subspecies of V. vinifera, and report the first evidence of inaperturate Vitis pollen from an archaeological site. We studied exemplar cases of plants with hermaphroditic flowers, belonging to the subspecies vinifera with fully developed male and female organs, cases of dioecious plants with male or female flowers, belonging to the wild subspecies sylvestris and cases of V. vinifera subsp. vinifera with morphologically hermaphroditic but functionally female flowers. The pollen produced by hermaphroditic and male flowers is usually trizonocolporate; the pollen produced by female flowers is inaperturate. This paper reports on the inaperturate pollen of Vitis found in an archeological site of the Po Plain, Northern Italy. The site dated to the Bronze Age, which is known to have been a critical age for the use of this plant with a transition from wild to domesticated Vitis in central Mediterranean. Can the inaperturate Vitis pollen be a marker of wild Vitis vinifera in prehistoric times? Palynology suggests a possible new investigation strategy on the ancient history of the wild and cultivated grapevine. The pollen dimorphism also implies a different production and dispersal of pollen of the wild and the domesticated subspecies. Grapevine plants are palynologically different from the other Mediterranean “cultural trees”. In fact, Olea, Juglans and Castanea, which are included in the OJC index, have the same pollen morphology and the same pollen dispersal, in wild and domesticated plants. In contrast, the signal of Vitis pollen in past records may be different depending on the hermaphroditic or dioecious subspecies.

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A Circular Chloroplast Genome of Fagus sylvatica Reveals High Conservation between Two Individuals from Germany and One Individual from Poland and an Alternate Direction of the Small Single-Copy Region

Forests ◽

10.3390/f12020180 ◽

2021 ◽

Vol 12 (2) ◽

pp. 180

Author(s):

Bagdevi Mishra ◽

Bartosz Ulaszewski ◽

Sebastian Ploch ◽

Jaroslaw Burczyk ◽

Marco Thines

Keyword(s):

Chloroplast Genome ◽

Fagus Sylvatica ◽

Pollen Dispersal ◽

European Beech ◽

Single Copy ◽

Migration History ◽

Chloroplast Genomes ◽

Long Read ◽

The Individual ◽

Small Single Copy

Chloroplasts are difficult to assemble because of the presence of large inverted repeats. At the same time, correct assemblies are important, as chloroplast loci are frequently used for biogeography and population genetics studies. In an attempt to elucidate the orientation of the single-copy regions and to find suitable loci for chloroplast single nucleotide polymorphism (SNP)-based studies, circular chloroplast sequences for the ultra-centenary reference individual of European Beech (Fagus sylvatica), Bhaga, and an additional Polish individual (named Jamy) was obtained based on hybrid assemblies. The chloroplast genome of Bhaga was 158,458 bp, and that of Jamy was 158,462 bp long. Using long-read mapping on the configuration inferred in this study and the one suggested in a previous study, we found an inverted orientation of the small single-copy region. The chloroplast genome of Bhaga and of the individual from Poland both have only two mismatches as well as three and two indels as compared to the previously published genome, respectively. The low divergence suggests low seed dispersal but high pollen dispersal. However, once chloroplast genomes become available from Pleistocene refugia, where a high degree of variation has been reported, they might prove useful for tracing the migration history of Fagus sylvatica in the Holocene.

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Pollen dispersal and genetic structure in a cajuput (Melaleuca cajuputi subsp. cajuputi) seed orchard in Yogyakarta, Indonesia

Australian Forestry ◽

10.1080/00049158.2021.1911079 ◽

2021 ◽

pp. 1-9

Author(s):

N. K. Kartikawati ◽

A. Rimbawanto ◽

M. Na’iem ◽

S. Indrioko ◽

J. C. Doran

Keyword(s):

Genetic Structure ◽

Pollen Dispersal ◽

Seed Orchard ◽

Melaleuca Cajuputi

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Spatial genetic substructure within natural populations of jack pine (Pinus banksiana)

Canadian Journal of Botany ◽

10.1139/b91-074 ◽

1991 ◽

Vol 69 (3) ◽

pp. 547-551 ◽

Cited By ~ 36

Author(s):

Chang Yi Xie ◽

Peggy Knowles

Keyword(s):

Spatial Autocorrelation ◽

Pinus Banksiana ◽

Pollen Dispersal ◽

Natural Populations ◽

Jack Pine ◽

Spatial Autocorrelation Analysis ◽

Autocorrelation Analysis ◽

Long Distance ◽

Genetic Substructure ◽

Good Agreement

Spatial autocorrelation analysis was used to investigate the geographic distribution of allozyme genotypes within three natural populations of jack pine (Pinus banksiana Lamb.). Results indicate that genetic substructuring within these populations is very weak and the extent differs among populations. These results are in good agreement with those inferred from mating-system studies. Factors such as the species' predominantly outbreeding system, high mortality of selfs and inbreds prior to reproduction, long-distance pollen dispersal, and the absence of strong microhabitat selection may be responsible for the observed weak genetic substructuring. Key words: jack pine, Pinus banksiana, genetic substructure, allozyme, spatial autocorrelation analysis.

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