Hermaphrodite Flowers Research Articles

IS THE FLOWER OF PULASAN (NEPHELIUM RAMBOUTAN-AKE) A PROTOGYNY OR PROTANDRY?

Pulasan is an androdioecious plant that has both male and hermaphrodite flowers on separate plants. The objectives of this study were to obtain data about the anatomical structure of pulasan flower and to investigate whether the pistil and the stamens of pulasan flower reach maturity at different times. The anatomical observation was done on compound flowers taken from three male trees and three hermaphrodite trees. Two compound flowers that still in buds, about to bloom and fully bloom were picked from each tree. Flowers were observed in a cross and longitudinal section. The results showed that the sepals of pulasan flower comprised of the uniseriate epidermis and multilayered polyhedral parenchymal cells. Stamen development started from the anther followed by the formation of the filament. The pollen of hermaphrodite pulasan flowers reached maturation earlier than the pistil. The pistil development started from the expansion of meristem cells in the center of the flower and ends with the warp of the stigma.

Evaluation of Silica Uptake from Foliar-Applied Silicon Nanoparticles in Melon (Cucumis melo L.) under Soilless Culture

Melon (Cucumis melo L.) is a fruit commodity that gets a great interest to be developed in Indonesia and has a high nutritional value. However, the fungal infection and pathogens in melon cultivation are considered significant problems that are difficult to manage. Therefore, efforts are needed to improve the productivity and quality of melon and prevent pest and disease attacks. One mineral nutrient that is assumed to enhance plant resistance and increase the quality and production of melon is silica. The purpose of the research was to evaluate silica absorption from foliar-applied silicon nanoparticles in melon under soilless culture and improve melon fruit's growth and quality by applying silica fertilizer. The experimental design used was a split-plot randomized complete block design 3 x 2 factorial pattern with four replicates. The main plot factor is silica fertilizer (Novelgro, water-soluble), consisting of three silica concentrations of 0.67; 1.33 ppm, and control. The spray volume of each treatment was 160 ml per plant with seven days' intervals and a frequency of three times. The subplot factor is melon varieties consisting of “Alisha” and “Glamour”. The findings showed that silica fertilizer significantly increased the plant height, stem diameter, internode length, total number of hermaphrodite flowers, number of hermaphrodite flowers that are swelling, while decreased the fruit moisture content and gave the best average fruit position. Instead, The “Glamour” variety gave the best response to plant growth and fruit quality. Moreover, the melon plant could absorb silica in the low category (<1% Si). The highest silica contents were found in the “Alisha” cultivar leaves and the “Glamour” cultivar's rinds treated with the silica concentration of 1.33 ppm as much as 0.34% and 0.30%, respectively.

SWATH-MS based quantitive proteomics reveal regulatory metabolism and networks of androdioecy breeding system in Osmanthus fragrans

BackgroundThe fragrant flower plant Osmanthus fragrans has an extremely rare androdioecious breeding system displaying the occurrence of males and hermaphrodites in a single population, which occupies a crucial intermediate stage in the evolutionary transition between hermaphroditism and dioecy. However, the molecular mechanism of androdioecy plant is very limited and still largely unknown.ResultsHere, we used SWATH-MS-based quantitative approach to study the proteome changes between male and hermaphroditic O. fragrans pistils. A total of 428 proteins of diverse functions were determined to show significant abundance changes including 210 up-regulated and 218 down-regulated proteins in male compared to hermaphroditic pistils. Functional categorization revealed that the differentially expressed proteins (DEPs) primarily distributed in the carbohydrate metabolism, secondary metabolism as well as signaling cascades. Further experimental analysis showed the substantial carbohydrates accumulation associated with promoted net photosynthetic rate and water use efficiency were observed in purplish red pedicel of hermaphroditic flower compared with green pedicel of male flower, implicating glucose metabolism serves as nutritional modulator for the differentiation of male and hermaphroditic flower. Meanwhile, the entire upregulation of secondary metabolism including flavonoids, isoprenoids and lignins seem to protect and maintain the male function in male flowers, well explaining important feature of androdioecy that aborted pistil of a male flower still has a male function. Furthermore, nine selected DEPs were validated via gene expression analysis, suggesting an extra layer of post-transcriptional regulation occurs during O. fragrans floral development.ConclusionTaken together, our findings represent the first SWATH-MS-based proteomic report in androdioecy plant O. fragrans, which reveal carbohydrate metabolism, secondary metabolism and post-transcriptional regulation contributing to the androdioecy breeding system and ultimately extend our understanding on genetic basis as well as the industrialization development of O. fragrans.

Rambutan genome revealed gene networks for spine formation and aril development

Rambutan is a popular tropical fruit known for its exotic appearance, has long flexible spines on shells, extraordinary aril growth, desirable nutrition, and a favorable taste. The genome of an elite rambutan cultivar Baoyan 7 was assembled into 328 Mb in 16 pseudo-chromosomes. Comparative genomics analysis between rambutan and lychee revealed that rambutan chromosomes 8 and 12 are collinear with lychee chromosome 1, which resulted in a chromosome fission event in rambutan (n = 16) or a fusion event in lychee (n = 15) after their divergence from a common ancestor 15.7 million years ago. Root development genes played a crucial role in spine development, such as endoplasmic reticulum pathway genes, jasmonic acid response genes, vascular bundle development genes, and K+ transport genes. Aril development was regulated by D-class genes (STK and SHP1), plant hormone and phenylpropanoid biosynthesis genes, and sugar metabolism genes. The lower rate of male sterility of hermaphroditic flowers appears to be regulated by MYB24. Population genomic analyses revealed genes in selective sweeps during domestication that are related to fruit morphology and environment stress response. These findings enhance our understanding of spine and aril development and provide genomic resources for rambutan improvement.

Activity and foraging behaviour of the hoverfly Eristalinus aeneus (Scopoli, 1763) in protected cultivation of mango (Mangifera indica L.).

The hoverfly Eristalinus aeneus is an important pollinator of crops and wild plants. However, there is a lack of detailed information about its foraging behaviour and its potential as a managed pollinator of mango. Given the growing economic importance of protected cultivation of mango, our aim is to study the flight activity and foraging behaviour of E. aeneus on this crop. Eristalinus aeneus displayed a bimodal daily activity, with peaks during mid-morning and mid-afternoon. The activity was maintained over a wide range of temperature (from 17.8 up to 37.4°C), light intensity (from 8.2 up to 57.4 klux) and relative humidity (from 19.0 up to 88.8%). The syrphids were active most of the time in this crop, and we observed five different types of activity: foraging (67%), resting (17%), flying (10%), grooming (4%) and walking (2%). This hoverfly visited hermaphrodite flowers more often than male flowers. On average, it visited 36.46 ± 13.92 flowers per 5 min, with a higher number of floral visits for nectar feeding. The duration of the visits to hermaphrodite and male flowers was similar but pollen-feeding visits lasted longer (6.44 s per flower) than nectar-feeding ones (5.51 s per flower). The highest number of visits to mango inflorescences was observed during the morning, but the longest visits occurred at midday. The implication of these results for the potential use of E. aeneus as a managed pollinator in protected cultivation of mango is discussed.

Comparison of reproductive organs structure in various genotypes of Phaseolus vulgaris grown under the same conditions in Mersin, Turkey

The common bean (Phaseolus vulgaris) is a plant having hermaphroditic flowers, which are self-fertilizing. Common bean is a important commercial crop and one of Turkey’s most valuable grain legumes for human consumption. Genetic variation exists within and between bean populations. These variations can have an impact on the plants morphology, including reproductive organs. Variations in size and length of reproductive organs may cause different cell numbers and various fertilization successes. In this study, the response of four determinate common bean genotypes (Akman, Bitlis 117, Göksun, and Karacaşehir) to reproductive organ structure was studied. Plants were grown at 21/16 °C (day/night) and 12 h photoperiod in a greenhouse in Mersin, Turkey. Besides focusing mainly on pollen development, fertilization success factors such as pod and seed set were also assessed. Pod and seed set were evaluated numerically for each genotype. For pollen morphology, flower buds of the equal growth stage of all four bean genotypes were collected, and these samples were analyzed by scanning electron microscopy. The species have distinct morphological characteristics concerning pollen size, ornamentation patterns of the exine, and endoaperture type. It is also crucial to examine pollen dispersion in the pollinated flowers, as it may influence reproductive success. However, pollen wall architecture was similar in all genotypes tested. Despite general morphological similarity, differences in pollen viability and pod and seed number were observed. Although Akman genotype had the largest flowers, the Karacaşehir genotype was found to be the most productive one. The findings presented here can be helpful for researchers studying bean breeding and those investigating the morphological variation in different Phaseolus genotypes.

A Review on Reproductive Biology and Breeding System in <I>Melia dubia</i> Cav.

A prime member of family Meliaceae, Melia dubia (Cav. Syn. Melia composita Willd.) is a multipurpose tree species with global significance. Although species bears versatile importance world over, information on reproductive biology and breeding system is scarce and limited. The initiation of advance generation breeding in Melia dubia needs special focus on floral morphology, biology and breeding system aspects. Therefore, a systematic review on reproductive biology of Melia dubia was conducted and has been presented in this paper. It reveals that species bears complex hermaphrodite flower with maximum flowering during mid of March. Though information on reproductive biology is extremely inadequate, anthesis occurs during morning hours and stigma attains receptivity two hours prior to that and continues upto twelve hours of anthesis. Information on pollination biology and breeding system of Melia dubia revealed predominance of self pollination and self compatibility with frequent visiting of insects during flowering. Hybridization activities in M. dubia have not yet been reported and need to be envisaged for further improvement of species.

Impact of the female and hermaphrodite forms of Opuntia robusta on the plant defence hypothesis

The optimal defence hypothesis predicts that increased plant defence capabilities, lower levels of damage, and lower investment in vegetative biomass will occur more frequently in sexual forms with higher resource-demanding tissue production and/or younger plant parts. We aimed to examine the effects of sexual form, cladode, and flower age on growth rate, herbivore damage, and 4-hydroxybenzoic acid (4-HBA), chlorogenic acid, and quercetin (QUE) concentrations in Opuntia robusta plants in central Mexico. Our findings demonstrated that hermaphrodite flowers showed faster growth and lesser damage than female flowers. The effect of cladode sexual forms on 4-HBA and QUE occurrence was consistent with the predictions of the optimal defence hypothesis. However, chlorogenic acid occurrences were not significantly affected by sexual forms. Old cladodes exhibited higher QUE and 4-HBA occurrences than young cladodes, and hermaphrodites exhibited higher 4-HBA concentrations than females. Resource allocation for reproduction and secondary metabolite production, and growth was higher and lower, respectively, in females, compared to hermaphrodites, indicating a trade-off between investment in reproduction, growth, and secondary metabolite production. Secondary metabolite concentrations in O. robusta plants were not negatively correlated with herbivore damage, and the two traits were not accurate predictors of plant reproductive output.

Induction of flowering and improvement of fruit yield and quality in pomegranate (Punica granatum) cv. Bhagwa by various plant growth regulators

The effect of different plant growth regulators on flowering, fruiting, yield, and quality of pomegranate (Punica granatum L.) cv. Bhagwa was studied in a field trial at ICAR - Indian Institute of Horticultural Research (IIHR), Bengaluru, during two seasons, namely ambe bahar (January–February) 2016 and hastha bahar (September–October) 2016-17. Nitrobenzene (NB) 1.0, 1.5, and 2.0 ml plant-1, Cycocel (CCC) 500, 1000, and 1500 ppm plant-1, Uracil 25 and 50 ppm plant-1, CCC 1000 ppm + Uracil 25 ppm plant-1, CCC 1500 ppm + Uracil 50 ppm plant-1, and Control were among the eleven treatments studied. The application of uracil 50 ppm plant-1 resulted in a higher number of hermaphrodite flowers plant-1 (264.7), number of fruits plant-1 (154.0), and fruit yield (27.1 kg/plant). Fruit weight (197.6 g), fruit length (6.64 cm), total aril weight (113.63 g), 100 aril weight (27.18 g), fruit juice weight (101.94 g), TSS content (19.96 OB), fruit anthocyanin content (6.46 mg 100 g) and low titrable acidity (0.41 percent) were recorded when CCC 1000 ppm + Uracil 25 ppm plant-1 was applied. During ambe bahar, the highest fruit width (6.90 cm) and volume (162.7 ml) were observed with CCC 1000 ppm and 1500 ppm plant-1, respectively. During hastha bahar, CCC 1500 ppm plant-1 resulted in a higher number of hermaphrodite flowers (287.8), the highest percentage of fruit set (86.10), the highest number of fruits plant-1 (156.66), the highest fruit yield (54.53 kg plant-1), the highest fruit weight (348.32 g), the longest fruit length (8.53 cm), and the largest fruit volume (8.53 cm) (33.93 ml), total aril weight (224.01 g), 100 aril weight (35.09 g), fruit juice weight (119.40 g) and TSS content (16.00 OB). A foliar spray of nitrobenzene 1.5 ml plant-1 compounded the high fruit anthocyanin content (6.47 mg 100g-1). As a result of the research, it can be concluded that CCC 1000 ppm + Uracil 25 ppm plant-1and CCC 1500 ppm plant-1were the most effective treatments for improving floral characters, fruiting, yield, and quality in pomegranate cv. Bhagwa during both seasons.

Differences in the flower visitor behaviour on female and hermaphroditic flowers of Cimicifuga simplex

ABSTRACT The behavioural patterns of flower-visiting insects are influenced by floral display size, floral reward, etc. We tested whether insects of various taxa visiting Cimicifuga simplex would change their behaviour between hermaphroditic and female flowers. Male-phase flowers of hermaphroditic ramets provide flower visitors with nectar and pollen as rewards, whereas female flowers of female ramets provide flower visitors with only nectar. The appearance of the both sexes in C. simplex is different with hermaphrodite being relatively large and female ramet being relatively small. Therefore, to investigate how sexual differences in floral rewards and conspicuousness affect flower visitor behaviour, we compared flower visitor behaviour between male-phase hermaphroditic ramets and female ramets. C. simplex was visited by the bumblebee Bombus beaticola beaticola (Hymenoptera), Vespula flaviceps (Hymenoptera), Anthomyiidae spp. (Diptera), Episyrphus balteatus (Diptera), and Pidonia aegrota (Coleoptera). The visitation frequency of all visitors, especially of bumblebees and dipteran insects, to male-phase hermaphroditic ramets was higher than that to female ramets. The number of flowers contacted per single visit to an inflorescence was significantly higher for hermaphroditic ramets than for female ramets in bumblebees, but no difference was found in other insect groups. These results suggest that bumblebees visit the low-reward female ramets less often than male-phase hermaphroditic ramets, and they stay on female ramets for a shorter time. In contrast, insects other than bumblebees seem to decide which flowers to visit according to how conspicuous the flowers are, but once they visit a ramet they continue to visit flowers on the ramet even if no pollen rewards there are.

Phenology of Flowering and Fruit Set in Snake Fruit (Salacca Sumatrana Becc.)

AbstractThe Sidimpuan snake fruit (Salacca sumatranaBecc.) tree flowers throughout the year. However, the fruits are produced seasonally. The level of production is directly related to flowering and fruit set. A low level of fruit formation results in a low number of fruits that can be harvested. A deeper understanding of the phenology of flowering and fruit set in Sidimpuan snake fruit may help solve the problem of low off-season production, and is the focus of this study. The study was conducted in the village of Palopat Maria, a subdistrict of Padangsidimpuan Hutaimbaru, Indonesia. The methodology included surveys and descriptive analysis with direct counting of inflorescences and fruits on each sample plant twice a week over each of three sampling periods (May–August 2016, September–December 2016, and January–April 2017). The results showed that the Sidimpuan snake fruit is a monoecious plant with hermaphrodite flowers. The inflorescences set at the base of the midrib of the fronds every 1.0–1.5 months. The plants had five–six flowering stages, and two–three stages of fruit set were observed. The period between the appearance of new flowers and fruit harvest lasted 5–6 months. The highest average number of flower bunches was observed in the January–April flowering period (6.23/tree) and the lowest was in May–August (5.33/tree, i.e., 14% less). The number of fruit bunches was the highest in May–August (4.37/tree), and the lowest in September–December, and was more than 40% less. Analysis of variance indicated that the flowering period significantly affected the percentage of fruit set. The highest fruit set was 85.5% during May–August, and the lowest was 44.0% during September–December. The average leaf nitrogen content in the flowering period of May–August and September–December was significantly different and higher than that in January–April. The average levels of phosphorus and potassium did not vary significantly throughout the year. The difference in fruit set affected the level of production in each flowering season.

Floral and reproductive biology and pollinators of Campomanesia guazumifolia (Cambess.) O. Berg., neglected species

Studies on the Myrtaceae family are mainly distributed in floristic surveys, reproductive studies of plant communities or related to family taxonomy. Based on this, the objective of the present study was to elucidate aspects of floral and reproductive biology and, of floral visitors from Campomanesia guazumifolia (Cambess.) O. Berg., a neglected species. Information was obtained on floral morphology and morphometry, anthesis, nectary, and structures attractive to pollinators, characterization of pollinators, receptiveness of stigma and maturing of the androecium components, and characterization of the reproductive system. Sete-capote tree has hermaphrodite flowers, and the floral opening occurs mainly during the daytime. Pollen grains was the main resource offered to pollinators. The flowers had mellow sweet odor, attracting mainly native bees and Apis melifera, which was characterized as effective pollinators. The species presents high reproductive efficiency and could be considered self-compatible; however, fertilization also occurs by cross-pollination.

Multiple independent recombinations led to hermaphroditism in grapevine

Hermaphroditic (perfect) flowers were a key trait in grapevine domestication, enabling a drastic increase in yields due to the efficiency of self-pollination in the domesticated grapevine (Vitis vinifera L. ssp. vinifera). In contrast, all extant wild Vitis species are dioecious, each plant having only male or female flowers. In this study, we identified the male (M) and female (f) haplotypes of the sex-determining region (SDR) in the wild grapevine species V. cinerea and confirmed the boundaries of the SDR. We also demonstrated that the SDR and its boundaries are precisely conserved across the Vitis genus using shotgun resequencing data of 556 wild and domesticated accessions from North America, East Asia, and Europe. A high linkage disequilibrium was found at the SDR in all wild grape species, while different recombination signatures were observed along the hermaphrodite (H) haplotype of 363 cultivated accessions, revealing two distinct H haplotypes, named H1 and H2. To further examine the H2 haplotype, we sequenced the genome of two grapevine cultivars, 'Riesling' and 'Chardonnay'. By reconstructing the first two H2 haplotypes, we estimated the divergence time between H1 and H2 haplotypes at ∼6 million years ago, which predates the domestication of grapevine (∼8,000 y ago). Our findings emphasize the important role of recombination suppression in maintaining dioecy in wild grape species and lend additional support to the hypothesis that at least two independent recombination events led to the reversion to hermaphroditism in grapevine.

Male sterility significantly elevates shape variation and fluctuating asymmetry of zygomorphic corolla in gynodioecious Glechoma hederacea (Lamiaceae)

Female flowers of gynodioecious plants usually have smaller corollas than bisexual flowers. This difference is explained as a developmental consequence of stamen abortion and as a result of stronger selection for larger corolla size in hermaphroditic flowers that solely ensure male function within populations. This study evaluated whether the size difference of zygomorphic corollas in a widely distributed gynodioecious herb Glechoma hederacea is accompanied by variation in shape and bilateral fluctuating asymmetry of sexually differentiated flowers. Geometric morphometric analyses of bilateral symmetry in the shapes of corolla lower lips showed that male-sterile flowers were significantly more plastic and asymmetric, implying that they may be subjected to weaker stabilizing selection for corolla shape in comparison to hermaphrodites. These results illustrated that sexual differentiation may be an important factor contributing to bilateral fluctuating asymmetry in the shape of zygomorphic flowers.

A leaky dimorphic sexual system and breeding system characterize a successful island colonist: the reproductive biology ofPlocama pendula(Rubiaceae)

AbstractIsland plants provide special opportunities for the study of evolution and ecology. In field and greenhouse studies we characterized a model reproductive system for Plocama pendula, endemic to the Canary Islands. This species has a complicated and not immediately obvious reproductive system. Pollination is biotic, and all flowers are morphologically hermaphroditic, but half of the plants characteristically bear flowers with nectar, pistils with reflexed stigmatic lobes and pollen-less anthers (i.e. they are functionally female flowers). The other half bear nectar-less flowers with abundant pollen and full-sized pistils that mostly have un-reflexed stigmatic lobes (i.e. they are hermaphroditic flowers functioning mostly as males). However, experiments show these pollen-bearing flowers to be self-compatible. Thus, the functionally male flowers have a breeding system that allows selfing in limited circumstances, but the functionally male flowers produce far fewer fruits than do functionally female flowers. With morphologically gynodioecious, functionally largely dioecious flowers, sometimes capable of selfing, the reproductive system of this species could be labelled as ‘leaky’ in many respects. Thus, we propose that P. pendula has colonized new habitats and persists in substantial populations at least in part because it manifests a reproductive system that is a model for successfully balancing the often-conflicting evolutionary demands of colonization, establishment and persistence.

Effect of Soil and Foliar Applications of Micronutrients on Flowering and Yield of Mango

The experiment was carried out during the spring and summer seasons of the year 2017-18 and 2018-19 at the Horticultural Research Farm, AAU, Anand to study the “Effect of soil and foliar applications of micronutrients on flowering and yield of mango variety”. The experimentcomprised of 13 treatments of different micronutrients application viz. FeSO4 100 g, ZnSO4 100 g, Borax 100 g and multimicronutrients grade-V 400 g as a soil application; FeSO4 0.5 %, ZnSO4 0.5 %, borax 0.2 % and multimicronutrients grade-IV 1.0 % as a foliar application and its combinassions and control (water spray). Soil application was done at second fortnight of September and foliar sprays of treatments were done at flower bud initiation, full bloom stage and pea stage initiationon 18 years old mango tree cv. Mallika. Experiment was laid out in a Completely Randomized Design (CRD) with three repetitions. Numbers of staminate, hermaphrodite and total number of flowers per panicle were found significant with respect to various micronutrients treatments during both the years of experiment. Maximum staminate flowers per panicle, hermaphrodite flowers per panicle and total number of flowers per panicle was found with soil application of multimicronutrients grade-V 400 g followed by foliar application of multimicronutrients grade-IV 1.0 % during both the years of study. The significantly higher number of fruits, average fruit weight and fruit yield per tree were recorded with soil application of multimicronutrients grade-V 400 g followed by foliar application of multimicronutrients grade-IV 1.0 % during the years 2017-18 and 2018-19.

Comparison of Cm ACS-7 Gene Expression in Melon (Cucumis melo L.) Flowers

Melon (Cucumis melo L.) is a member of the Cucurbitaceae family spread throughout the world. Melons have very varied sexual types, which can be important information in genetic analysis and breeding. Sex type jumps from genetic factors, environmental factors, and environmental conditions. The aim of this study was the expression of CmACS-7 gene expression in melon flowers in various sexual types. This study used melons with andromonoecious sexual types (Melodi Gama 1 and Melodi Gama 3 cultivars) and monoecious (PI 371795 and Bartek). This study uses quantitative PCR analysis using real-time PCR with relative quantitative methods. RNA was isolated and then synthesized into cDNA, then amplified using specific primers. The number of cDNA specific genes was analyzed using Real-time PCR to calculate the level of gene expression. The results showed that the CmACS-7 gene was expressed more in female and hermaphrodite flowers than in male flowers. In male flowers with andromonoecious sexual type, the CmACS-7 gene is expressed more than in male flowers with monoecious sexual type. This research is expected to be important information in breeding melon plants.

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)

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.

Breeding system in a population of the globose cactus Mammillaria magnimamma at Valle del Mezquital, Mexico

Background: The breeding system of Mammillaria magnimamma was initially described as hermaphroditic. However, some individuals in a natural population at Valle del Mezquital exhibited a seemingly non-functional androecium.
 Objectives: To determine the breeding system of M. magnimamma through morphological characterization of floral types.
 Study site and years: The study was conducted at Valle del Mezquital, Mexico, during the 2019 reproductive season.
 Methods: We characterized floral polymorphism by means of scanning electron microscopy and morphometric analysis of 18 floral traits. Pollinator frequency, size and number of seeds, and germination rate were compared between flower types.
 Results: 87.85 % of the plants were hermaphrodites, and 12.15 % were females with non-functional androecium, with significantly smaller stamens, indehiscent anthers, and malformed pollen. Female flowers were shorter (14.007 ± 0.742 mm) and had smaller (1.856 ± 0.151 mm) nectar chambers than hermaphroditic flowers (15.821 ± 0.450 and 2.194 ± 0.090 mm, respectively). Although pollinators visited hermaphrodites (124 visits) about twice as often as pistillate flowers (60 visits), the latter produced more numerous ( F 1,26 = 8.320, P = 0.003) and larger ( Hc = 4.637, P = 0.031) seeds that also germinated faster ( Hc = 70.59, P < 0.0001).
 Conclusions: This M. magnimamma population exhibits a gynodioecious breeding system with both hermaphroditic and male sterile female plants. Females produce more, higher quality seeds, which favour their maintenance in the population.

Andromonoecy in Solanum lycocarpum A. St. ‐Hil. (Solanaceae): Floral attributes, visitors and variation in sexual expression over time

AbstractSexual expression in andromonoecious species—those in which a single individual can bear both staminate and hermaphroditic flowers—may vary among reproductive events in the same plant, among individuals and across populations. This variation influences, in turn, the individual contribution of hermaphroditic plants via male and female fitness functions (i.e., Lloydʼs phenotypic gender). However, temporal variation in sexual expression in andromonoecious species and its relationship with seasonal changes in climatic conditions remain poorly understood. Here we analyze floral attributes, visitors and variation in sexual expression in three populations of Solanum lycocarpum A. St. ‐Hil. Seasonality in the production of floral types, the mating system and floral visitors were also investigated. Hermaphroditic flowers produced more pollen grains, but the pollen of staminate flowers had higher viability. Only hermaphroditic flowers produced fruits, and ovules in staminate flowers were sterile. Solanum lycocarpum is mainly pollinated by large bees with the ability to vibrate flowers. Phenotypic gender varied throughout the year, and the seasonal production of staminate flowers is associated with the local climate. We suggest that the higher and seasonally variable relative abundance of staminate flowers compared to the low and uniform production of hermaphroditic flowers may be explained by (a) the very high energetic costs incurred in producing large fruits, which in turn make hermaphroditic flower production very costly, and (b) the potentially lower energy expenditure of the smaller staminate flowers with reduced pistils and non‐viable ovules that allow them to rapidly respond to climate variability.