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 Assessment of weather effect on flower morphogenesis and fruit set in mango varieties in central India

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
N. R. RANGARE ◽  
MANISH BHAN ◽  
S. K. PANDEY
Keyword(s):  
Sex Ratio ◽  
Minimum Temperature ◽  
Fruit Set ◽  
Male Flower ◽  
Central India ◽  
Flower Initiation ◽  
Hermaphrodite Flower ◽  
Flower Morphogenesis ◽  
Bud Initiation ◽  
Flower Sex Ratio

A two-year field experiment was initiated in 2017-18 and 2018-19 years simultaneously to assess temperature on flower morphogenesis stages, flower sex ratio (hermaphrodite/staminate male flower) and fruit set in monoembryonic Langra and Amrapali varieties. Different dates of flower phenological stages viz., bud, panicle, bloom and flower initiation, pea, marble, egg, and maturity of fruits were recorded. The Langra variety exhibited bud initiation after mid December whereas Amrapali variety by the end of December. The range of mean maximum / minimum temperature as 26-31/10-12 °C promoted hermaphrodite flowers per panicle by 74 per cent in Langra variety, whereas range of 27-29/11-13 °C favored by 35 per cent in Amrapali variety. A positive and significant correlation between total number of flower / panicle and flower sex ratio in both the varieties suggested that higher temperature during initial flower phenologies improved number of hermaphrodite flowers. A mean minimum temperature for producing more number of hermaphrodite flower  exhibited a range of 11-14 °C under central Indian conditions.  Fruit set was maximum during pea stage and decline afterwards in marble and fruit maturity stages due to sudden rise in temperature at marble stage that caused in drop down of humidity thereby resulted in fruit drop in both the varieties.

scholarly journals Brassinosteriod-induced Femaleness in Cucumber and Relationship to Ethylene Production

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1763-1767 ◽  
Author(s):  
Ekaterina Papadopoulou ◽  
Rebecca Grumet
Keyword(s):  
Ethylene Production ◽  
Female Flower ◽  
Sex Expression ◽  
Bisexual Flower ◽  
Flower Production ◽  
Total Female ◽  
The Difference ◽  
Male Flowers ◽  
Cucurbitaceae Family

The Cucurbitaceae family is noted for a diversity of sex expression phenotypes. Typically, a phase of male flowers precedes either female or bisexual flower production. Sex determination of individual flowers is regulated by a combination of genetic, environmental, and hormonal factors. Ethylene, auxins, and gibberellins have all been shown to influence flower sex expression in cucurbits. Ethylene, which promotes femaleness, plays a predominant role. In this study, we tested whether brassinosteroids (BR), a more recently identified class of plant hormones, also influences cucurbit sex expression. Applied epi-brassinolide (epi-BL) caused a significant decrease in time of appearance of the first female flower on monoecious cucumber plants, and increased total female flowers on the main stem. Increasing concentrations had a stronger effect. Of the three species tested, cucumber, melon and zucchini, cucumber was the most responsive to BR. Application of epi-BL also caused an increase in ethylene production by cucumber and zucchini seedlings, suggesting that the BR effect may be mediated by ethylene. To investigate the possible relationship between BR and ethylene on sex expression, we identified the concentration of ethephon (5 ppm) that caused an increase in ethylene production comparable to that induced by 10 μm epi-BL (approximately two-fold). Treatment with 5 ppm ethephon was sufficient to increase femaleness of cucumber plants, but not zucchini plants, suggesting that the difference in response to epi-BL treatment may reflect differences in sensitivity to ethylene. Collectively, our results indicate that application of brassinosteroids to cucumber cause earlier and increased female flower production, and that the effects may be mediated, at least in part, by brassinosteroid-induced production of ethylene.

scholarly journals Karakter Morfologi dan Sitologi Bunga Pepaya Merah Delima

2019 ◽  
Vol 7 (1) ◽  
pp. 21
Author(s):  
Noflindawati Noflindawati ◽  
Aswaldi Anwar ◽  
Yusniwati Yusniwati ◽  
Agus Sutanto
Keyword(s):  
Natural Sciences ◽  
Hermaphrodite Flower ◽  
Tropical Fruit ◽  
Biology Department ◽  
Research Material ◽  
West Sumatra ◽  
The Difference ◽  
Male Flowers ◽  
Female Flowers ◽  
Perfect Flower

The papaya plant has three types of flowering, male flowers, female flowers, and perfect flower (hermaphrodite). The difference in interest affects the shape of the resulting fruit. This study aimed to characterize morphology and cytology of papaya flowers. The study was conducted in Tropical Fruit  Research  Institute at Solok and Laboratory of SPT at the Biology Department of the Faculty of Mathematics and Natural Sciences, Andalas University, Padang, West Sumatra. The research material uses papaya flowers Merah Delima variety  from KP. Aripan Balitbu Troipka. The results showed the male flowers of male plants were smaller than the male flowers of the perfect plant. The difference of hermaphrodite flower of pentandria with hermaphrodite elongata flower, among others, the number of stamens, the length of the stem and the size of the ovary. Hermaphrodite pentandria has a number of stamens 5 while elongata has stamens 10

scholarly journals The effect of ethepon treatment on the formation of flower in melon (Cucumis melo L.)

2018 ◽  
Vol 1 ◽  
pp. 00002
Author(s):  
Budi Setiadi Daryono ◽  
Eko Prasetya ◽  
Sumarlina Sumarlina ◽  
Dian Sartika ◽  
Aprilia Sufi Subiastuti
Keyword(s):  
Sex Expression ◽  
Fruit Production ◽  
Hermaphrodite Flower ◽  
Significance Level ◽  
Randomized Design ◽  
Plant Chemical ◽  
Monoecious Plant ◽  
Male Flowers ◽  
Cucumis Melo L

<p class="Abstract">Melon is a potential horticultural crop which the production is increased significantly each year in Indonesia. However, a melon plant that has been widely developed in Indonesia faced a problem due to the high tropical temperature that affected the fall of flower causing failure in fruit production. In addition, the variation of sex expression in melon flower is important for genetic analysis and breeding programs. Ethepon is one of plant chemical growth regulator that is known to change the sex expression of the plant by increasing the number of female flower in monoecious plant especially Cucurbitaceae. This research aimed to analyze the effect of ethepon treatment on the sex determination of melon flower. This study was conducted by 3 stages treatment of ethepon during March – July 2014, namely when 2, 5, and 7 weeks after planting. Split-plot design has been used with the main plots were arranged in a completely randomized design by cultivating different melon cultivars i.e: Melodi Gama 1, Melodi Gama 3, Bartek, and PI 371795. The data were analyzed by F-test and Duncan Multiple Range Test (DMRT) with significance level at 5 % using software SAS 9.3. The result showed that ethepon treatment affected the formation of melon flower by increasing the number of female or hermaphrodite flower and decreasing the number of male flowers, especially in the concentration of 75 ppm and 100 ppm but with different responses by different cultivar.&nbsp;<o:p></o:p></p>

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..

scholarly journals (214) Brassinosteroid-induced Femaleness in Cucumber and Relationship to Ethylene Production

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1057C-1057
Author(s):  
Ekaterina Papadopoulou ◽  
Rebecca Grumet
Keyword(s):  
Ethylene Production ◽  
Female Flower ◽  
Sex Expression ◽  
Predominant Role ◽  
Flower Production ◽  
Total Female ◽  
The Difference ◽  
Male Flowers ◽  
Female Flowers

The cucurbit family is noted for diversity in sex expression phenotypes. Typically, a phase of male flowers precedes the appearance of female or hermaphrodite flowers. Sex determination of individual flowers is regulated by genetic, environmental, and hormonal factors. Ethylene, auxins, and gibberellins all influence flower sex, with ethylene, which promotes femaleness, playing a predominant role. In this study, we tested whether brassinosteroids, a more recently identified class of plant hormones, also influence cucurbit sex expression. Applied epi-brassinolide (epi-BL) caused a significant decrease in time of appearance of the first female flower on monoecious cucumber plants, and increased total female flowers on the main stem. Increasing concentrations had a stronger effect. Of the three species tested, cucumber, melon, and zucchini, cucumber was the most responsive. Application of epi-BL also caused an increase in ethylene production by cucumber and zucchini seedlings, suggesting that the BR effect may be mediated by ethylene. To investigate the possible relationship between BR and ethylene on sex expression, we identified the concentration of ethephon (5 ppm) that caused an increase in ethylene production comparable to that induced by 10 μm epi-BL (about two-fold). Treatment with 5 ppm ethephon was sufficient to increase femaleness of cucumber plants, but not zucchini plants, suggesting that the difference in response to epi-BL may reflect differences in sensitivity to ethylene. Collectively, our results indicate that application of brassinosteroids to cucumber cause earlier and increased female flower production, and that the effects may be mediated, at least in part, by brassinosteroid-induced increased production of ethylene.

Response of snake cucumber (Cucumis melo var. pubescens) to some plant regulators

1982 ◽  
Vol 99 (3) ◽  
pp. 587-590 ◽  
Author(s):  
E. El-Kholy ◽  
H. Hafez
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Cucumis Melo ◽  
Total Yield ◽  
Female Flower ◽  
Sex Expression ◽  
Significant Suppression ◽  
Yield Production ◽  
Male Flowers ◽  
Fruit Characters

SUMMARYTrials were conducted during the summer seasons (1978 and 1979) at the Faculty of Agriculture, Elminia University, to evaluate the effect of some growth regulators on sex expression, sex ratio and yield production of snake cucumber. The results obtained showed that both sex expression and ratio could be modified with plant regulator sprays even under the long and high temperature conditions of Elminia governorate. All plant regulators induced the formation of the first female flower at lower nodes compared with the control. There was significant suppression of male flowers in plants sprayed with plant regulators. All the treatments gave an increase in total yield and improved fruit characters.

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.

scholarly journals A Quantitative Genetic Analysis of Nuclear-Cytoplasmic Male Sterility in Structured Populations of Silene vulgaris

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 833-841 ◽  
Author(s):  
Douglas R Taylor ◽  
Matthew S Olson ◽  
David E McCauley
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Genetic Analysis ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Sex Expression ◽  
Silene Vulgaris ◽  
Population Variance ◽  
Quantitative Genetic ◽  
Quantitative Genetic Analysis

Abstract Gynodioecy, the coexistence of functionally female and hermaphroditic morphs within plant populations, often has a complicated genetic basis involving several cytoplasmic male-sterility factors and nuclear restorers. This complexity has made it difficult to study the genetics and evolution of gynodioecy in natural populations. We use a quantitative genetic analysis of crosses within and among populations of Silene vulgaris to partition genetic variance for sex expression into nuclear and cytoplasmic components. We also use mitochondrial markers to determine whether cytoplasmic effects on sex expression can be traced to mitochondrial variance. Cytoplasmic variation and epistatic interactions between nuclear and cytoplasmic loci accounted for a significant portion of the variation in sex expression among the crosses. Source population also accounted for a significant portion of the sex ratio variation. Crosses among populations greatly enhanced the dam (cytoplasmic) effect, indicating that most among-population variance was at cytoplasmic loci. This is supported by the large among-population variance in the frequency of mitochondrial haplotypes, which also accounted for a significant portion of the sex ratio variance in our data. We discuss the similarities between the population structure we observed at loci that influence sex expression and previous work on putatively neutral loci, as well as the implications this has for what mechanisms may create and maintain population structure at loci that are influenced by natural selection.

Male-biased sex ratio in Argulus canadensis Wilson, 1916 (Crustacea: Branchiura) ectoparasitic on sticklebacks

1989 ◽  
Vol 67 (8) ◽  
pp. 2078-2080 ◽  
Author(s):  
Robert Poulin ◽  
Gerard J. FitzGerald
Keyword(s):  
Salt Marsh ◽  
Sex Ratio ◽  
Laboratory Experiments ◽  
Fish Predation ◽  
Reproductive Behaviour ◽  
Egg Deposition ◽  
Alternative Hypotheses ◽  
Biased Sex Ratio ◽  
The Difference ◽  
Fish Hosts

Females of the ectoparasitic crustacean Argulus canadensis must leave their fish hosts at least temporarily to deposit their eggs on the substrate. To test the hypothesis that this difference in reproductive behaviour between the two sexes could result in male-biased sex ratios on their stickleback hosts, we sampled sticklebacks in tide pools of a Quebec salt marsh from early July to early September 1986. During this period, fish harboured significantly more male than female A. canadensis. Laboratory experiments were done to test two alternative hypotheses offered to explain this biased sex ratio. The first hypothesis was that male A. canadensis were more successful than females in attacking their stickleback hosts; however, we found no differences in attack success on their hosts between the two parasite sexes. The second hypothesis was that sticklebacks ate more female than male A. canadensis. Although males were less vulnerable to fish predation than females, the difference was not significant. We conclude that sexual differences in reproductive behaviour, i.e., egg deposition behaviour of females, can account for the male-biased sex ratio of A. canadensis on sticklebacks.

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