Gender polymorphism in flowers of Silene vulgaris (Moench) Garcke (Caryophyllaceae)

Abstract

Silene vulgaris occurs in Israel as a stolonifcrous tetraploid which forms mostly sexually polymorphic populations. Fully hermaphrodite and fully male‐sterile plants are linked by a range of intermediate forms which are gynomonoecious and bear hermaphrodite, male‐sterile, and partially male‐sterile flowers. Male‐sterile flowers differ from hermaphrodite ones by having a narrower calyx, a shorter corolla, a thicker style, and a considerably larger stigmatic area with longer papillae which are more markedly bulbous basally. In individual anthers of hermaphrodite flowers, diameters of stained pollen grains showed a continuous variation from 36 to 80 μm with a modal value of 56. About 30% of pollen was found to be non‐stainable. Reduction in male fertility occurs at different levels, from small or inviable pollen grains through abortion of single anthers, abortion of entire androecia, and through different degrees of gynomonoecy to totally male‐sterile individuals. The proportion of stainable pollen to ovules in hermaphrodite flowers alone was found to be less than 100. From the data presented, less than a third of all ovules produced in the different kinds of flower develop into seeds. This may reflect an inadequacy of pollen, which the local population of S. vulgaris can tolerate because of its stoloniferous habit.

Population Size, Pollination and Breeding System of Silene stockenii Chater (Caryophyllaceae), an Annual Gynodioecious Species of Southern Spain

“…Sexual polymorphism is a common event in the genus Silene, and gynodioecy is known in other species (lolls, 1984;jells and Chenier, 1989;Shykoff, 1988Shykoff, , 1992Dulberger and Horovitz, 1984), but this is the first report of gynodioecy in an annual species of Silene in Europe.…”

Pollen grain numbers, ovule numbers and pollen-ovule ratios in Caryophylloideae: correlation with breeding system, pollination, life form, style number, and sexual system

“…According to the classification of Cruden (1977), most of these species are either facultative autogamous or facultative xenogamous. In an investigation of S. vulgaris, Dulberger and Horovitz (1984) stated that the P/O ratio, calculated for hermaphrodite flowers alone without taking male-sterile components of populations into account, is well below values given by Cruden (1977) for xenogamous species. Our data show that all investigated Caryophylloideae have relatively low P/O ratios for xenogamous plants.…”

The evolution and maintenance of gynodioecy in sexually and vegetatively reproducing plants

“…Kay and Stevens (1986) discussed a number of dioecious and subdioecious species in the flora of the British Isles that rely heavily on vegetative reproduction, and several examples of vegetatively reproducing gynodioecious species are given in table 2. Lloyd (1973) Origanum vulgare rhizomes Lewis and Crowe (1956), Kheyr-Pour (1980) Saxifraga granulata bulbils Stevens and Richards (1985) Silene vulgaris stolons Dulberger and Horovitz (1984) Succisa pratensis lateral buds Kay (1982) Vegetative reproduction per se has several important consequences for gynodioecy. One consequence concerns the nature of fitness differences between hermaphrodites and females.…”