Search results for "Hermaphroditic Organisms"
showing 4 items of 4 documents
Variable mycorrhizal benefits on the reproductive output ofGeranium sylvaticum, with special emphasis on the intermediate phenotype
2012
In several gynodioecious species, intermediate sex between female and hermaphrodite has been reported, but few studies have investigated fitness parameters of this intermediate phenotype. Here, we examined the interactions between plant sex and arbuscular mycorrhizal (AM) fungal species affecting the reproductive output of Geranium sylvaticum, a sexually polymorphic plant species with frequent intermediate sexes between females and hermaphrodites, using a common garden experiment. Flowering phenology, AM colonisation levels and several plant vegetative and reproductive parameters, including seed and pollen production, were measured. Differences among sexes were detected in flowering, fruit …
Sex change in plants and animals: a unified perspective
2014
The capacity of organisms to change their sex has evolved independently in several plant and animal lineages. Sex change has been widely studied, but research approaches have differed for plants and animals, and conclusions have often been taxon-specific. Although sex allocation theory provides a unifying framework for the study of sex change, this unity has not always been appreciated, especially in the botanical literature. Here, we review sex change with regard to its representation in relation to taxonomy and other sexual systems, with regard to its suggested adaptive benefits, and to the role of taxon-specific body architecture, such as modularity and gonadal structure. We highlight di…
A cost of Wolbachia-induced sex reversal and female-biased sex ratios: decrease in female fertility after sperm depletion in a terrestrial isopod.
2004
A number of parasites are vertically transmitted to new host generations via female eggs. In such cases, host reproduction is an intimate component of parasite fitness and no cost of the infection on host reproduction is expected to evolve. A number of these parasites distort host sex ratios towards females, thereby increasing either parasite fitness or the proportion of the host that transmit the parasite. In terrestrial isopods (woodlice), Wolbachia bacteria are responsible for sex reversion and female-biased sex ratios, changing genetic males into functional neo-females. Although sex ratio distortion is a powerful means for parasites to increase in frequency in host populations, it also …
Nectar sugar production across floral phases in the Gynodioecious Protandrous Plant Geranium sylvaticum [corrected].
2013
Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar production in nectar standing crop and secretion rate were investigated in Geranium sylvaticum, a gynodioecious plant species with protandry (i.e. with hermaphrodite flowers releasing their pollen before th…