scholarly journals Rapid dissolution of dioecy by experimental evolution

2019 ◽  
Author(s):  
G. G. Cossard ◽  
J. F. Gerchen ◽  
X. Li ◽  
Y. Cuenot ◽  
J. R. Pannell
Keyword(s):  
Experimental Evolution ◽  
Male Flower ◽  
Fold Increase ◽  
Sex Expression ◽  
Recent Analysis ◽  
Evolutionary Transitions ◽  
Sexual Systems ◽  
Major Transition ◽  
Rapid Dissolution ◽  
Male Flowers

AbstractEvolutionary transitions from hermaphroditism to dioecy have been frequent in flowering plants, but recent analysis indicates that reversions from dioecy to hermaphroditism have also been common. Here, we use experimental evolution to expose a mechanism for such reversions. We removed males from dioecious populations of the wind-pollinated plant Mercurialis annua and allowed natural selection to act on the remaining females that varied in their propensity for the occasional production of male flowers; such ‘leaky’ sex expression is common in both males and females of dioecious plants. Over only four generations, females evolved a 23-fold increase in average male-flower production. The phenotypic masculinization of females was also sufficient to render them effective at siring progeny in the presence of males. Our study illustrates the rapid dissolution of dioecy and the evolution of functional hermaphroditism under conditions that may frequently occur during periods of low population density, repeated colonization, or range expansion. It thereby experimentally validates a mechanism for a major transition in plant sexual systems..

REGULATION OF SEX EXPRESSION IN DESERT AND MEDITERRANEAN POPULATIONS OF AN ANDROMONOECIOUS PLANT (GAGEA CHLORANTHA, LILIACEAE)

1998 ◽  
Vol 46 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Lorne M. Wolfe
Keyword(s):  
Sex Ratio ◽  
Male Flower ◽  
Sex Expression ◽  
Male Reproduction ◽  
Rainfall Gradient ◽  
Hermaphrodite Flower ◽  
Mediterranean Populations ◽  
Female Function ◽  
The Difference ◽  
Male Flowers

This study examined issues related to the ecology of andromonoecy in Gagea chlorantha (Liliaceae), a perennial geophyte that grows in desert and Mediterranean-type habitats in Israel. Andromonoecy is a plant sexual system where individuals produce both male and hermaphrodite flowers and is thought to have evolved to optimize resource allocation to male and female function. Individuals of this species produced 1–6 flowers, and flower production was significantly correlated with the size of the storage organ (bulb). Three sexual phenotypes were found to exist: those that made only male flowers, plants that made only hermaphrodite flowers, and those that produced both flower types. Two lines of evidence suggest that hermaphroditic reproduction is more costly than male reproduction: (1) hermaphroditic flowers were heavier than male flowers in terms of dry biomass; (2) bulb size was greater on single-flower plants that were hermaphrodite compared to male. In addition, bulb size was greater on multiple-flowered plants that made a hermaphrodite flower as the last flower, compared to those that made a male flower. The floral sex ratio varied extensively along a latitudinal rainfall gradient within Israel. The five Mediterranean populations were male-biased. In contrast, the production of males in the three Negev desert populations was extremely rare, and approximately 94% of the flowers were hermaphrodite. The difference in sex ratio between the two habitat types is explained in terms of environmental unpredictability.

scholarly journals When to be a male? Role of resource-limitation and pollinators in determining floral sex in an andromonoecious spiderwort

2020 ◽  
Author(s):  
Asawari Albal ◽  
G Azad ◽  
Saket Shrotri ◽  
Vinita Gowda
Keyword(s):  
Resource Allocation ◽  
Resource Constraints ◽  
Apis Cerana ◽  
Resource Limitation ◽  
Sex Expression ◽  
Sexual Systems ◽  
Pollinator Preference ◽  
Optimal Resource ◽  
Male Flowers ◽  
Nutrient Resources

AbstractThe evolution and maintenance of sexual systems in plants is often driven by resource allocation and pollinator preferences, and very little is known about their role in determining floral sex expression in plants. In annual, entomophilous plants three major constraints can be identified towards optimal reproduction: 1) nutrient resources available from the environment, 2) nutrient resources allocated towards reproduction, i.e., fruits vs. flowers, and 3) pollinator visitations.Andromonoecy is a sexual system where plants bear both staminate and hermaphrodite flowers on the same inflorescence. The optimal resource allocation hypothesis suggests that under nutrient constraints, plants will produce more male flowers since they are energetically cheaper to produce over the more expensive hermaphrodite flowers. We test this hypothesis in the andromonoecious Murdannia simplex (Commelinaceae) by quantifying male and hermaphrodite flowers in a natural population and contrasting the distribution of the two sexes in plants from two resource conditions (stream population vs. plateau population). We next carried out choice experiments to test pollinator preference towards a specific sex.We found that in M. simplex, production of hermaphrodite flowers is resource-dependent and under resource constraints fewer numbers of flowers were produced and most of them were males. We failed to observe pollinator preference towards either sex but Amegilla spp. and Apis cerana showed higher visitation towards the most abundant sex within a trial, suggesting frequency-dependent visitation. Thus, we conclude that environmentally driven resource constraints play a bigger role in driving floral sex expression in Murdannia over direct pollinator-driven constraints.

scholarly journals Comparative RNA-Seq analysis reveals genes associated with masculinization in female Cannabis sativa

Planta ◽  
2021 ◽  
Vol 253 (1) ◽  
Author(s):  
Ayelign M. Adal ◽  
Ketan Doshi ◽  
Larry Holbrook ◽  
Soheil S. Mahmoud
Keyword(s):  
Differentially Expressed Genes ◽  
Cannabis Sativa ◽  
Expression Patterns ◽  
Plant Biotechnology ◽  
Male Flower ◽  
Sex Expression ◽  
Differentially Expressed ◽  
Rna Seq ◽  
Rna Profiling ◽  
Male Flowers

Abstract Main conclusion Using RNA profiling, we identified several silver thiosulfate-induced genes that potentially control the masculinization of female Cannabis sativa plants. Abstract Genetically female Cannabis sativa plants normally bear female flowers, but can develop male flowers in response to environmental and developmental cues. In an attempt to elucidate the molecular elements responsible for sex expression in C. sativa plants, we developed genetically female lines producing both female and chemically-induced male flowers. Furthermore, we carried out RNA-Seq assays aimed at identifying differentially expressed genes responsible for male flower development in female plants. The results revealed over 10,500 differentially expressed genes, of which around 200 potentially control masculinization of female cannabis plants. These genes include transcription factors and other genes involved in male organ (i.e., anther and pollen) development, as well as genes involved in phytohormone signalling and male-biased phenotypes. The expressions of 15 of these genes were further validated by qPCR assay confirming similar expression patterns to that of RNA-Seq data. These genes would be useful for understanding predisposed plants producing flowers of both sex types in the same plant, and help breeders to regulate the masculinization of female plants through targeted breeding and plant biotechnology.

Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae)

2002 ◽  
Vol 80 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
Lorena Ashworth ◽  
Leonardo Galetto
Keyword(s):  
Reproductive Output ◽  
Male Flower ◽  
Female Flower ◽  
Cucurbita Maxima ◽  
Nectar Production ◽  
Male And Female ◽  
Nectar Sugar Composition ◽  
Nectar Sugar ◽  
Male Flowers ◽  
Female Flowers

In dioecious and monoecious plants that depend on animal vectors for reproduction, pollinators have to be attracted to male and female flowers for pollination to be effective. In the monoecious Cucurbita maxima ssp. andreana, male flowers are produced in greater quantity, are spatially more exposed to pollinators and offer pollen in addition to nectar as floral rewards. Nectar traits were compared between male and female flowers to determine any differences in the characteristics of the main reward offered to pollinators. Nectar chemical composition and sugar proportions were similar between flower types. Total nectar sugar production per female flower was threefold higher than per male flower, and nectar removal did not have any effect on total nectar production in both flower morphs. Pollinators reduced nectar standing crops to similar and very scarce amounts in both flower types. Results indicate indirectly that pollinators are consuming more nectar from female flowers, suggesting that the higher nectar production in female flowers may be a reward-based strategy to achieve the high female reproductive output observed in this species.Key words: Cucurbitaceae, Cucurbita maxima ssp. andreana, nectar production, nectar sugar composition, removal effects, standing crop.

scholarly journals The Effects of Silver Nitrate Applications on the Flower Quantity of Cucumbers (Cucumis sativus L.)

2011 ◽  
Vol 39 (1) ◽  
pp. 139 ◽  
Author(s):  
Deniz KARAKAYA ◽  
Hüseyin PADEM
Keyword(s):  
Silver Nitrate ◽  
Cucumis Sativus ◽  
Male Flower ◽  
Flower Formation ◽  
Cucumis Sativus L ◽  
Male Flowers ◽  
Female Flowers

This study was conducted to investigate the effects of silver nitrate (AgNO3) on the flower quantity of cucumbers. The seeds used in this study, which was carried out in a plastic greenhouse, in the Gazi village of Antalya Province (Turkey) the during spring and autumn 2005 breeding periods, were ‘Mostar F1’ (designated as ‘GND1’) and ‘Vesco Seeds Beith Alpha F1 (26.50 F1)’, designated as ‘GND2’ and those are the types having common production. The silver nitrate application was performed by the method of spraying on the growth tips of plants and 0, 250, 500, 750, and 1000 ppm silver nitrate doses were administered. The research was conducted with 4 repetitions having 5 plants in each repetition according to the Random Parcel Trial Pattern. In order to determine the effects of the applications, the effects of a number of female flowers and male flowers on generative characteristics of planting periods (spring and fall) were identified and the results were statistically evaluated. According to the results obtained in this research, AgNO3 has led to the formation of male flowers (no male flower formation in control), has increased the number of male flowers, and has led to a decrease in the number of female flowers. The increase in the number of male flowers varied according to the periods (in ‘GND2’).

scholarly journals The effect of growth regulators on sex expression in melon (Cucumis melo L.)

2013 ◽  
Vol 13 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Zdenka Girek ◽  
Slaven Prodanovic ◽  
Jasmina Zdravkovic ◽  
Tomislav Zivanovic ◽  
Milan Ugrinovic ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Growth Regulators ◽  
Cucumis Melo ◽  
Staminate Flower ◽  
Sex Expression ◽  
Male Flowers ◽  
Cucumis Melo L ◽  
Perfect Flower

Seven traits related to flowering and sex expression in melon were studied and their reaction to application of two growth regulators (ethrel and gibberellic acid) was observed. Four monoecious genotypes (Sesame, ED-3, ED-4, Pobeditel) and four andromonoecious genotypes (Chinese muskmelon, Anannas, Fiata, A2-3lb) had been used for experiments. According to the results, ethrel had higher effects on the investigated traits than gibberellic acid. Ethrel increased the number of perfect flowers per plant for 7.18 (31.42%), reduced the number of male flowers per plant for 21.47 (17.98%), affected earlier appearance of the first pistillate/perfect flower for 3.68 days, and delayed the appearance of the first staminate flower for 16.07 days. Changes in the last two traits caused an extension of the period from the emergence of the first pistillate/perfect to the first staminate flower from 0.1 to 21.57 days, which represents the strongest effect of ethrel. Gibberellic acid had generally opposite effects on the studied traits.

scholarly journals Sex expression and floral diversity inJatropha curcas: a population study in its center of origin

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2071 ◽  
Author(s):  
María de Lourdes Adriano-Anaya ◽  
Edilma Pérez-Castillo ◽  
Miguel Salvador-Figueroa ◽  
Sonia Ruiz-González ◽  
Alfredo Vázquez-Ovando ◽  
...  
Keyword(s):  
Floral Morphology ◽  
Male Flower ◽  
Distance Matrix ◽  
Sex Expression ◽  
Southern Mexico ◽  
Center Of Origin ◽  
Floral Diversity ◽  
Productive Potential ◽  
Flower Diameter ◽  
Improvement Programs

Sex expression and floral morphology studies are central to understand breeding behavior and to define the productive potential of plant genotypes. In particular, the new bioenergy cropJatropha curcasL. has been classified as a monoecious species. Nonetheless, there is no information about its reproductive diversity in the Mesoamerican region, which is considered its center of origin and diversification. Thus, we determined sex expression and floral morphology inJ. curcaspopulations from southern Mexico and Guatemala. Our results showed that most ofJ. curcasspecimens had typical inflorescences with separate sexes (monoecious); meanwhile, the rest were atypical (gynoecious, androecious, andromonoecious, androgynomonoecious). The most important variables to group these populations, based on a discriminant analysis, were: male flower diameter, female petal length and male nectary length. From southern Mexico “Guerrero” was the most diverse population, and “Centro” had the highest variability among the populations from Chiapas. A cluster analysis showed that the accessions from southern Mexico were grouped without showing any correlation with the geographical origin, while those accessions with atypical sexuality were grouped together. To answer the question of how informative are floral morphological traits compared to molecular markers, we perform a Mantel correlation test between the distance matrix generated in this study and the genetic distance matrix (AFLP) previously reported for the same accessions. We found significant correlation between data at the level of accessions. Our results contribute to design genetic improvement programs by using sexually and morphologically contrasting plants from the center of origin.

scholarly journals Outbreeding and inbreeding strategies in herbaceous-shrubby communities in the Venezuelan Gran Sabana Plateau

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Nelson Ramírez ◽  
Omaira Hokche
Keyword(s):  
Plant Species ◽  
Carbon Metabolism ◽  
Life Form ◽  
Sex Expression ◽  
Perennial Herb ◽  
Sexual System ◽  
Dioecious Species ◽  
Successional Stage ◽  
Sexual Systems ◽  
Perennial Herbs

Abstract Breeding system, sexual system, temporal variation in sex expression and herkogamy were evaluated in seven herbaceous-shrubby communities from the Gran Sabana Plateau, Venezuela. This analysis was conducted considering the life form, substrate type, succulence, carbon metabolism, nutritional relation, successional stage, pollination system specificity and endemism of plant species. Of the 348 plant species studied, 73.8 % were hermaphrodite, 16.9 % were monoecious and 9.2 % were dioecious. Plant sexual systems such as dichogamy and herkogamy were associated with life form, nutritional relations, carbon metabolism and pollination systems. Most species were adichogamous, followed by protandrous and protogynous. Protandry was high for perennial herbs, annual herbs and trees, and protogyny was most frequent in perennial herbs. Protandrous and protogynous species were frequently anemophilous. Herkogamy was higher than non-herkogamy. Herkogamy was higher for trees, shrubs and liana; higher in monophilous and lower in anemophilous species. Most of the hermaphrodites were herkogamous and adichogamous species. In contrast, monoecy were commonly perennial herb and dichogamous species and frequently associated with anemophily. Dioecious species were trees and shrubs and with polyphilous pollination. Dioecy was the most frequent sexual system for endemic species. Hermaphrodite species were similarly distributed across plant communities. Monoecy was slightly higher for savanna and fallow than the other communities, and dioecy was higher for shrublands and secondary bushland. Most plant species were non-agamospermous, non-spontaneous self-pollinated and xenogamous. Partially self-incompatible dominated, followed by self-incompatible, partially cross-incompatible and the lowest frequency corresponded to cross-incompatible species. All these results are discussed in the context of evolutionary and ecological trends.

scholarly journals Environmental and physiological effects on cross-ability and seed production of greenhouse cucumber

2019 ◽  
Vol 41 (2) ◽  
pp. 134-143
Author(s):  
Maryam Golabadi ◽  
Sezai Ercisli ◽  
Forough Ahmadi
Keyword(s):  
Seed Production ◽  
Block Design ◽  
Young Male ◽  
Male Flower ◽  
Early Morning ◽  
Randomized Complete Block Design ◽  
Flower Age ◽  
Greenhouse Cucumber ◽  
Male Flowers ◽  
Empty Seeds

Abstract: Seed production depends on many factors. In this study, two independent experiments were carried out to investigate the effects of pollination time, crossed node spacing, male flower age, number of crossings on each plant and deletion/non-deletion of other fruits in the crossed nodes on the cross-ability and seed production in greenhouse cucumber. In every experiment, three mentioned factors were assayed based on factorial experiment as a randomized complete block design. Crosses were done on 10 plants in every replication of treatments. The results showed that pollination at 8:00‒9:45 AM, led to higher amount of full seed weight in contrast to other times of pollination. Increasing crossed node spacing from 2‒3 to 4‒5 nodes led to an increase in the number of empty seeds, which was ascribed to the reduced seed production. The highest amount of number of seeds per fruit, seed weigh and number of full seeds were obtained when young male flowers were used. Moreover, higher seed production was obtained from five, instead three crossings on each plant, and the non-deletion of fruits on the crossed nodes. Overall, higher percentage of seed production per fruit was obtained when crossing was done with young male flower in early morning and high number of crossing in every plant.

scholarly journals Hermaphroditism and Gonochorism

2020 ◽  
pp. 197-241
Author(s):  
Chiara Benvenuto ◽  
Stephen C. Weeks
Keyword(s):  
Reproductive System ◽  
Reproductive Strategies ◽  
Population Level ◽  
Population Densities ◽  
Ecological Constraints ◽  
Evolutionary Transitions ◽  
Colonizing Species ◽  
Sexual Systems ◽  
Theoretical Perspectives ◽  
Successful Group

This chapter compares two sexual systems: hermaphroditism (each individual can produce gametes of either sex) and gonochorism (each individual produces gametes of only one of the two distinct sexes) in crustaceans. These two main sexual systems contain a variety of alternative modes of reproduction, which are of great interest from applied and theoretical perspectives. The chapter focuses on the description, prevalence, analysis, and interpretation of these sexual systems, centering on their evolutionary transitions. The ecological correlates of each reproductive system are also explored. In particular, the prevalence of “unusual” (non-gonochoristic) reproductive strategies has been identified under low population densities and in unpredictable/unstable environments, often linked to specific habitats or lifestyles (such as parasitism) and in colonizing species. Finally, population-level consequences of some sexual systems are considered, especially in terms of sex ratios. The chapter aims to provide a broad and extensive overview of the evolution, adaptation, ecological constraints, and implications of the various reproductive modes in this extraordinarily successful group of organisms.

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