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Premise of research. Anacardiaceae comprise two subfamilies (Anacardioideae and Spondioideae) with small nectariferous flowers that are typically morphologically bisexual, whereas sometimes only th...

Premise of research. Whole-genome duplication is often associated with the evolution of dimorphic sexual systems; however, the association is not universal, and the evolutionary pathway(s) underlyi...

Ficus species are characterized by their unusual enclosed inflorescences (figs) and their relationship with obligate pollinator fig wasps (Agaonidae). Fig trees have a variety of growth forms, but true epiphytes are rare, and one example is Ficus deltoidea of Southeast Asia. Presumably as an adaptation to epiphytism, inflorescence design in this species is exceptional, with very few flowers in female (seed‐producing) figs and unusually large seeds. Figs on male (pollinator offspring‐generating) trees have many more flowers. Many fig wasps pollinate one fig each, but because of the low number of flowers per fig, efficient utilization by F. deltoidea's pollinators depends on pollinators entering several female figs. We hypothesized that it is in the interest of the plants to allow pollinators to re‐emerge from figs on both male and female trees and that selection favors pollinator roaming because it increases their own reproductive success. Our manipulations of Blastophaga sp. pollinators in a Malaysian oil palm plantation confirmed that individual pollinators do routinely enter several figs of both sexes. Entering additional figs generated more seeds per pollinator on female trees and more pollinator offspring on male trees. Offspring sex ratios in subsequently entered figs were often less female‐biased than in the first figs they entered, which reduced their immediate value to male trees because only female offspring carry their pollen. Small numbers of large seeds in female figs of epiphytic F. deltoidea may reflect constraints on overall female fig size, because pollinator exploitation depends on mutual mimicry between male and female figs., Blastophaga sp. pollinators routinely enter several figs of both sexes and generated more seeds per pollinator on female trees and more offspring on male trees. Pollinator offspring sex ratios in subsequently entered figs (circles) were often less female‐biased than in the first figs they entered (squares).

Garcinia subelliptica Merr. (called “fukugi” in Japanese) is a dioecious tree species, which has traditionally been planted as windbreak forests in the coast of Ryukyu islands. Although effective a...

Dioecy allows separation of female and male functions and therefore facilitates separate co‐evolutionary pathways with pollinators and seed dispersers. In monoecious figs, pollinators' offspring develop inside the syconium by consuming some of the seeds. Flower‐stage syconia must attract pollinators, then ripen and attract seed dispersers. In dioecious figs, male (“gall”) figs produce pollen but not viable seeds, as the pollinators' larvae eat all seeds, while female (“seed”) figs produce mostly viable seeds, as pollinators cannot oviposit in the ovules. Hence, gall and seed figs are under selection to attract pollinators, but only seed figs must attract seed dispersers. We test the hypothesis that seed and gall syconia at the flower stage will be similar, while at the fruiting stage they will differ. Likewise, monoecious syconia will be more similar to seed than gall figs because they must attract both pollinators and seed dispersers. We quantified syconium characteristics for 24 dioecious and 11 monoecious fig species and recorded frugivore visits. We show that seed and gall syconia are similar at the flower stage but differ at the fruit stage; monoecious syconia are more similar to seed syconia than they are to gall syconia; seed and gall syconia differentiate through their ontogeny from flower to fruit stages; and frugivores visit more monoecious and seed syconia than gall syconia. We suggest that similarity at the flower stage likely enhances pollination in both seed and gall figs and that differentiation after pollination likely enhances attractiveness to seed dispersers of syconia containing viable seeds. These ontogenetic differences between monoecious and dioecious species provide evidence of divergent responses to selection by pollinators and seed dispersers., Dioecious figs offer an excellent opportunity to test the importance of mutualists to select for flower and fruit‐stage traits. At the flower stage, both male and females need to attract pollinators, but at the fruit stage only females need to attract seed disperser, as males do not bear viable seeds. We found that figs of both sexes indeed share traits at the flower stage but differentiate at the fruit stage, which is concordant with the hypothesis that mutualists select for flower and fruit appearance in the genus.

Diospyros dussaudii is a poorly known species and previous descriptions lacked details about its female flowers and fruits. The species had not been recorded since type collections were made in 1913. As a result of our Diospyros research in Thailand, new specimens and data are now available for this species. In this study, we provide an updated morphological description, illustrations, lectotypification and a distribution map. The species was previously reported to be endemic to Laos; as such, the occurrences in Thailand greatly expand the distribution of the species. In addition, we analysed the phylogenetic relationships between D. dussaudii and other Diospyros species from Southeast Asia and other regions, using DNA sequence data from eight plastid regions. Our phylogenetic analyses indicate that D. dussaudii is closely related to D. castanea, D. dasyphylla and D. insidiosa. Their taxonomic affinities are discussed.

Dioecious plants are obligate outcrossers with separate male and female individuals, which can result in decreased seed set with increasing distance between the sexes. Wind pollination is a common correlate of dioecy, yet combined wind and insect pollination (ambophily) could be advantageous in compensating for decreased pollen flow to isolated females. Dioecious, ambophilous gymnosperms Ephedra (Gnetales) secrete pollination drops (PDs) in female cones that capture airborne pollen and attract ants that feed on them. Plant sugary secretions commonly reward ants in exchange for indirect plant defense against herbivores, and more rarely for pollination. We conducted field experiments to investigate whether ants are pollinators and/or plant defenders of South American Ephedra triandra, and whether their contribution to seed set and seed cone protection varies with distance between female and male plants. We quantified pollen flow in the wind and assessed the effectiveness of ants as pollinators by investigating their relative contribution to seed set, and their visitation rate in female plants at increasing distance from the nearest male. Ants accounted for most insect visits to female cones of E. triandra, where they consumed PDs, and pollen load was larger on bigger ants without reduction in pollen viability. While wind pollination was the main contributor to seed set overall, the relative contribution of ants was distance dependent. Ant contribution to seed set was not significant at shorter distances, yet at the farthest distance from the nearest male (23 m), where 20 times less pollen reached females, ants enhanced seed set by 30% compared to plants depending solely on wind pollination. We found no evidence that ants contribute to plant defense by preventing seed cone damage. Our results suggest that, despite their short-range movements, ants can offset pollen limitation in isolated females of wind-pollinated plants with separate sexes. We propose that ants enhance plant reproductive success via targeted delivery of airborne pollen, through frequent contact with ovule tips while consuming PDs. Our study constitutes the first experimental quantification of distance-dependent contribution of ants to pollination and provides a working hypothesis for ambophily in other dioecious plants lacking pollinator reward in male plants.

PREMISE Five to six percent of angiosperm species exhibit a dioecious sexual system, with unisexual "male" or "female" flowers borne on separate plants. The consequent need for inter-individual pollen exchange is a special challenge for taxa where pollen is the sole pollinator reward. Dioecious Australian Solanum assure visits from pollen-foraging bees via production of inaperturate pollen in functionally female (morphologically bisexual) flowers. Biochemical composition of pollen from Australian Solanum has not been assessed nor compared to porate pollen from staminate flowers to reveal whether these flowers differ in their pollinator reward potential. METHODS Porate pollen from male flowers and inaperturate pollen from functionally female flowers of two functionally dioecious Australian species were compared for protein and amino acid content. We also assessed pollen from bisexual and staminate flowers of a closely related andromonoecious species, in which all pollen is porate, as a comparison across co-occurring sexual systems. RESULTS In both functionally dioecious species, porate pollen grains from staminate flowers had significantly higher levels of proteins and amino acids than inaperturate pollen grains from functionally female flowers. Levels of proteins and amino acids were highest in bisexual and staminate flowers of the andromonoecious species. CONCLUSIONS Higher levels of proteins and amino acids in porate pollen of "male" flowers in our functionally dioecious Solanum species suggests a greater nutritive reward for bees foraging on "male" plants than for those foraging on functionally "female" plants. Greater reward in porate pollen (including andromonoecious species) may be connected to the potential to generate a pollen tube.

Background The 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. Results Here, 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. Conclusion Taken 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.

Many Arctic plants overcome limited time budgets and energy budgets by selfing, increasing the risk of inbreeding. Gynodioecious breeding systems allows for selfing by hermaphrodites, whereas enforced outcrossing through females lowers risk of inbreeding. Females persist due to female advantage in the system. Using the gynodioecious species Silene acaulis (L.) Jacq., we compared establishment performance and female frequency in 17 populations in open, sparsely vegetated habitats versus closed, denser vegetated habitats, across a regional climate gradient in high-Arctic Svalbard. For two populations, genetics were performed using microsatellites to compare inbreeding levels between habitats. As S. acaulis is a pioneer species, we expected denser vegetation to represent more competitive environments, reducing establishment performance and increasing female frequency due to female advantage. We expected similar responses to harsher regional climate. Establishment performance was reduced in closed habitats and harsher climate, but female frequency was slightly lower in closed habitats and did not differ between regional climates. High inbreeding levels may indicate that female advantage is counteracted by pollen limitation. However, female frequency increased with latitude. Lower sun angle at higher latitudes reduce the heat-trap effect of the cushion growth form, and female advantage might be expressed as response to reduced microclimate amelioration.

PCD role in unisexual flowers. The developmental processes underlying the transition from hermaphroditism to unisexuality are key to understanding variation and evolution of floral structure and function. A detailed examination of the cytological and histological patterns involved in pollen and ovule development of staminate and pistillate flowers in the dioecious Opuntia robusta was undertaken, and the potential involvement of programmed cell death in the abortion of the sex whorls was explored. Flowers initiated development as hermaphrodites and became functionally unisexual by anthesis. Female individuals have pistillate flowers with a conspicuous stigma, functional ovary, collapsed stamens and no pollen grains. Male individuals have staminate flowers, with large yellow anthers, abundant pollen grains, underdeveloped stigma, style and an ovary that rarely produced ovules. In pistillate flowers, anther abortion resulted from the premature degradation of the tapetum by PCD, followed by irregular deposition of callose wall around the microsporocytes, and finally by microspore degradation. In staminate flowers, the stigma could support pollen germination; however, the ovaries were reduced, with evidence of placental arrest and ovule abortion through PCD, when ovules were present. We demonstrate that PCD is recruited in both pistillate and staminate flower development; however, it occurs at different times of floral development. This study contributes to the understanding of the nature of the O. robusta breeding system and identifies developmental landmarks that contribute to sexual determination in Cactaceae.

Silene latifolia Poiret of Eurasia has established in North America, prompting this structural study of its mature unisexual buds and flowers. Floral nectaries, anther and stigma changes, and vestigial reproductive structures were studied using light and scanning electron microscopy. In staminate flowers, anthers dehisced before anthesis and >90% of their pollen was liberated within 36 h. Accumulated in the tubular calyx, nectar descended an anthophore from the stomatal-bearing nectary at the stamen bases. Nectary tissue surrounded the pistillode, a central filamentous organ lacking ovules but tipped by hairs resembling stigmatic papillae. In pistillate flowers, nectar flowed into an inflated calyx. The annular nectary had 10 regularly spaced, stomatal-lined craters and was continuous with the adaxial surfaces of the infertile antisepalous and epipetalous staminodes. Key elements of entomophilous pollination leading to successful sexual reproduction of this invasive species include secondary nectar presentation from disparate floral nectaries that, for pistillate flowers, also incorporate the staminodes; rapid pollen release from anthers; and elongation of papillae by tip growth that enhances each stigma’s receptive surface. Context is also provided for future studies of floral nectary development in this model dioecious species.

As harbingers of bursting growth, flower buds and leaf buds generally show similar surface morphologies but different structural and functional changes. Dioecious plants further generate four types of Female/Male Flower/Leaf Buds (FFB, FLB, MFB, and MLB), showing a complex regulation. However, little is known about their underlying molecular mechanisms. Here, we exemplify the woody dioecious Salix linearistipularis to investigate their morphological characteristics and potential molecular mechanisms by combining cytological, physiological, phenological, and transcriptomic datasets. First, FFB and MFB have simultaneous development dynamics and so do FLB and MLB. Interestingly, FLB and MLB show very similar expression profiles preparing for photosynthesis and stress-tolerance, whereas FFB and MFB show great similarities but also striking sexual differences. Comparing flower buds and leaf buds after their revival from dormancy shows different cold- and vernalization-responsive genes (e.g. SliVRN1, SliAGL19, and SliAGL24), implying different programming processes for dormancy breaking between the buds. Moreover, except SliAP3, the expression of ABCDE model genes is consistent with their roles in the buds, suggesting a conserved mechanism of flower development between dioecious Salix and hermaphrodite Arabidopsis. Finally, considering sex-associated genes (e.g. SliCLE25, SliTPS21, and SliARR9) on Salix chromosomes and other reports, we hypothesize a dynamic model of sex determination on chromosomes 15 and 19 in the last ancestor of Salix and Populus but evolutionarily on 15 in Salix after their divergence. Together, our study provides new insights into the molecular mechanisms of dioecious four-type buds by showing the genes involved in their development, dormancy breaking, flowering, and sexual association.

SUMMARY Brandies of male and female plants of the dioecious Leucadendron rubrum Burm. f. were collected on the site of the Weikamp weather-station in the Jonkershoek State Forest, Stellenbosch, from July 1990 to September 1991. Xylem sap was extracted from the branches by vacuum extraction. HPLC was employed to purify the xylem sap and to separate the cytokinins prior to quantitation by ELISA. The cytokinin levels in the purified plant samples were determined using rabbit antiserum-based ELISAs for the determination of the levels of the cytokinins DHZR and IPA, and a trans-ZR specific monoclonal antibody-based ELISA for the determination of the levels of the cytokinin ZR. It was observed that the levels of the cytokinins DHZR and ZR did not differ significantly between male and female plants but did correlate with the seasonal growth patterns. The levels of the cytokinin IPA, in male and female plants of L. rubrum, not only correlated specifically with the different seasonal growth patterns observed but differed significantly between male and female plants. Peaks in the levels of all three cytokinins. i.e. ZR, DHZR and IPA, occurred during the study period. These peaks corresponded with the phenological development of L. rubrum, specifically with vegetative bud break and inflorescence differentiation and appeared to be synchronized with the growth and development. An attempt was also made to correlate cytokinin levels with the extreme differences in morphological characters exhibited by male and female plants, and possibly to explain to what extent these phytohormones influence sex expression in L. rubrum

The stages of floral development in staminate and pistillate plants of hop (Humulus lupulus) were defined using scanning electron microscopy and light microscopy. Vegetative meristems of male and female plants are morphologically indistinguishable. On transition to the reproductive phase, inflorescence apices reduce greatly in size and striking developmental sex differences become apparent. The first sex-specific differences occur extremely early in floral ontogeny. Both male and female plants initiate inflorescence meristems at each leaf node, each meristem being enclosed within a bract. Male secondary inflorescence meristems give rise to clusters of asynchronously developing flowers. Female inflorescence meristems produce flowers arranged in 'cones'. Each male floral meristem initiates a whorl of five sepal primordia, followed by an inner whorl of five stamen primordia. There is no sign of carpel development at any stage. In females, two carpel primordia are initiated, surrounded at their base by a vestigial perianth whorl. No stamen development is observed. Several monoecious lines carry bisexual flowers, either within cymose panicles or within the basal bracts of terminal female inflorescences. Bisexual flowers usually possess perianth, stamen and carpel whorls. The central whorls are often highly variable, and range from a pair of stigmas fused to a thin central filament to a well developed gynoecium. Chimaeric central whorls consisting of fused staminoid-carpelloid structures also occur. Sex differences in unisexual hop flowers are determined at an extremely early stage in ontogeny. The inappropriate set of sex organs is suppressed before it becomes visible or, more probably, it is not initiated at all. Genes directing the development of sex are likely to act at an extremely early stage, well in advance of floral organogenesis. The sex chromosomes of dioecious hop plants are described, as well as the chromosome constitutions of monoecious plants and those carrying bisexual flowers.

RESUMEN Maytenus boaria Molina (Celastraceae) es un árbol nativo siempreverde de amplia distribución en Chile, con alto potencial económico por los diversos usos tradicionales descritos. A pesar de esto, existe escasa y confusa información biológica de la especie. El objetivo de este estudio fue ampliar el conocimiento sobre aspectos reproductivos y el sistema sexual de M. boaria, además de la arquitectura de la copa y su fenomorfología. El estudio se realizó entre agosto y diciembre de 2016, con individuos adultos (n=17) seleccionados en sectores urbanos de la Región Metropolitana. Se realizó un ensayo de polinización y se identificó el sexo de las flores de cada árbol seleccionado. Además, se realizó un diagrama fenomorfológico de la especie a través de la interpretación modular de la arquitectura y la identificación de sus fenofases. Los resultados indican que M. boaria es dioica y andromonoica; presenta una baja autogamia autónoma y es una especie no apomíctica que necesita de vectores de polinización para la producción de semillas. Posee cuatro módulos arquitectónicos en su copa -dolicoblasto de yema apical, dolicoblasto de yema axilar, inflorescencia y braquiblasto temporal reproductivo- dispuestos en dos unidades arquitecturales. Los aspectos reproductivos analizados y la fenomorfología de esta especie indican que estaría en un proceso evolutivo respecto a la funcionalidad de las flores hermafroditas, lo que ha sido planteado como un paso intermedio del hermafroditismo a la dioecia. Un mayor conocimiento de estas temáticas permitirá un mejor entendimiento de la autoecología de la especie, para un adecuado manejo productivo de esta.

Dioecious plants constitute 7% of all angiosperm species, yet they occur in many habitat types, partially through the deployment of sexual dimorphisms that assist in reproduction. In the present work, the dioecious monocot Lomandra leucocephala ssp. robusta (Asparagaceae: Lomandroideae) was studied to understand how sexual dimorphisms can assist species conservation and inform us of a species’ potential significance in an ecosystem. Floral display was sexually dimorphic, as male inflorescences were displayed more prominently and more conspicuously in UV range. Male nectar analysed by thin-layer chromatography contained a higher glucose content than female nectar. However, both sexes contained hexose-rich nectar, a common indicator of generalist pollination, which was supported by observations of floral visitors. Floral extract comparison conducted via gas chromatography-mass spectrometry showed that male extracts contained more compounds that potentially convey greater resistance to biotic and abiotic threats. Chemical comparison of leaves by high performance liquid chromatography with peak area ratio analysis revealed this technique could be used as a tool for gender identification of individuals during non-flowering periods. Due to the generalist pollination mechanisms of L. leucocephala ssp. robusta, may have an important role in the conservation and support of local insect populations. The presence of chemical biotic and abiotic resistance may also make L. leucocephala ssp. robusta a significant contributor to the ongoing stabilisation of the sand dunes. Conservation efforts required for L. leucocephala ssp. robusta are likely to be minimal, as pollination services are provided by a diversity of pollinating taxa, including introduced species, which will be abundant regardless of variable flowering periods. Further observational study of L. leucocephala ssp. robusta pollinators and differences in pollinator visitation behaviours between sexes is recommended to better understand efficient pollination for the species, and potentially reveal a greater extent of ecosystem benefit for this species.

Monteverdia ilicifolia, conhecida popularmente como espinheira-santa, é uma planta medicinal nativa do Brasil utilizada no tratamento de gastrites e úlceras gástricas. Este trabalho teve como objetivos avaliar a morfologia e biologia floral, caracterizar o sistema reprodutivo e descrever a fenologia reprodutiva de M. ilicifolia. Foram feitas análises de morfologia e biologia floral em plantas de espinheira-santa de um Banco Ativo de Germoplasma. O sistema reprodutivo foi avaliado por meio de testes de autopolinização, apomixia, polinização cruzada, polinização natural e geitonogamia. As fenofases reprodutivas foram acompanhadas durante dois anos e correlacionadas a variáveis climáticas. Todas as flores avaliadas são morfologicamente hermafroditas, no entanto foram encontrados três tipos florais quanto a expressão sexual: flores funcionalmente femininas, flores funcionalmente masculinas e flores hermafroditas. As flores funcionalmente masculinas e funcionalmente femininas ocorrem em diferentes plantas, caracterizando um processo evolutivo para a dioicia nessa espécie. Os tipos florais podem ser diferenciados comparando o comprimento estames com o comprimento do estilete, posição dos estames, a coloração das anteras e a quantidade de pólen em cada flor. A espécie apresentou sistema reprodutivo preferencialmente alógamo. O período reprodutivo ocorreu de junho até fevereiro, sendo que as fenofases reprodutivas estão correlacionadas com a temperatura e o comprimento do dia.

In many flowering plants, floral scents are a significant trait for visitors, playing an important role in attracting pollinators and/or detracting herbivores. The evolution of flowering plants from hermaphroditism to dioecy is often accompanied by sexual dimorphism in floral scent. In this study, floral scents emitted by different sexual morphs of the subdioecious shrub Eurya japonica Thunb. were collected using a dynamic headspace method, and sexual and temporal variations were evaluated by gas chromatography–mass spectrometry (GC–MS). Two volatiles, α‐pinene and linalool, were identified as the major components of floral scents in females, hermaphrodites, and males. The males emit higher amounts of floral scents, particularly α‐pinene, compared to females or hermaphrodites. Floral scents emitted by males generally decrease as flowers enter senescence, whereas those from females or hermaphrodites do not significantly differ. Intraspecific variations in floral scents of subdioecious species provided by this study would contribute to better understanding of sexual dimorphism in floral scent.

Background: In dioecious plants, females and males associate differently with mycorrhizal fungi, but interactions with other rhizosphere organisms are less well studied.Aims: We investigate...

Excoecaria agallocha is a deciduous tree species dispersed as mangrove associate in oligohaline to polyhaline areas of the mangrove forest. The existence of male and female tree ratio is 2:1. The ratio of male to female flowers is 16:1. It is an constrained out-crosser and is pollinated by insects like bees, flies, butterflies, and wind, which constitute ambophily. Anemophily make certain the realization of sexual reproduction if the insect pollinators are nor present and such a breeding system is a “fail-safe” strategy for reproductive assurance during colonization. Natural fruit set rate is 92%. Fruit predation by Chrysocoris partricius is 25%; it consumes the fruits prior to their fall from the mother plant. This tree species occupies the cleared or open areas within the mangrove forest and acts as an invasive mangrove associate.

Introduction Mauritia flexuosa is a dioecious species native to the Amazon, and the gender identification can currently be determined through the differentiation between female and male flowers in the first flowering. Objectives To identify variations in the metabolome profiles of pooled and individual samples of leaves from female and male plants of M. flexuosa in reproductive phase, and the plant in its vegetative phase, using two extraction systems. Material and methods Extractions of leaves were separately conducted using deuterated water and methanol. The extracts were evaluated by NMR spectroscopy and chemometric methods. Results Different NMR spectroscopic profiles were observed for females, males, and plants in the vegetative phase. Significant variations were found in the carbohydrate and fatty acid contents for the aqueous and methanolic extracts, respectively. Although principal component analysis (PCA) has not been efficient to distinguish the genders, orthogonal signal correction/partial least squares-discriminant analysis (OPLS-DA) was able to successfully differentiate male and female plants in the reproductive phase, independently on the sampling approach. For plants in the vegetative phase, OPLS-DA method from aqueous extracts of M. flexuosa leaves also distinguished female samples from the others and showed a small overlap between male and young plants, while the classification model was not able to be used for prediction. Conclusions NMR spectroscopy and chemometric-based approach was demonstrated to be useful in the metabolic study of dioecy in M. flexuosa. The extracts of the leaves allowed for differentiation between male and female plants; however, for plants in the vegetative phase, the identification of the gender was not effective. Copyright © 2018 John Wiley & Sons, Ltd.

Based on the literature, we assumed the presence of several morphological forms of flowers of the dioecy species Antennaria dioica (L.) Gaertn. We investigated 6000 flowers from three sites in Europe. As a result of this study, we allocated three morphological types of flowers: female, male, and hermaphroditic (2.5% sample). Variability of the degree of reduction of different organs, especially in the case of male flowers, was detected.

Sphedamnocarpus andersonii, a new species from the Ihorombe Region of Madagascar, is described and illustrated. The twiggy, white-flowered shrubs are characterized by linear leaves, unique in the genus.

Cannabis sativa (2n = 2x = 20) is a popular species belonging to the Cannabaceae family. Despite its use for medical, recreational, and industrial purposes as well as its long history, the genetic research on this species is in its infancy due to the legal implications and the prohibition campaigns. The recent legalization of Cannabis in many countries along with the use of genomics boosted the approaches aimed at marker-assisted selection, germplasm management, genetic discrimination, and authentication of cultivars. Nonetheless, the exploitation of molecular markers for the development of commercial varieties through marker-assisted breeding schemes is still rare. The present study aimed to develop an informative panel of simple sequence repeat markers to be used for the genotyping of high breeding value C. sativa lines. Starting from 41 nuclear SSR designated by in silico analyses, we selected 20 highly polymorphic and discriminant loci that were tested in 104 individuals belonging to 11 distinct hemp varieties. The selected markers were successful in accessing homozygosity, genetic uniformity, and genetic variation within and among varieties. Population structure analysis identified eight genetic groups, clustering individuals based on sexual behaviors (dioecious and monoecious) and geographical origins. Overall, this study provides important tools for the genetic characterization, authentication, conservation of biodiversity, genetic improvement and traceability of this increasingly important plant species.