Gynodioecy in Silene vulgaris (Caryophyllaceae): progeny success, experimental design, and maternal effects

TitleGynodioecy in Silene vulgaris (Caryophyllaceae): progeny success, experimental design, and maternal effects
Publication TypeJournal Article
Year of Publication1989
AuthorsJolls CL, Chenier TC
JournalAmerican Journal of Botany
Volume76
Issue9
Pagination1360-1367
KeywordsSYSTEMS
Abstract

This study documents the comparative success of seeds and seedlings of the perennial gynodioecious-gynomonoecious weed, Silene vulgaris, in the greenhouse. The importance of experimental design is stressed by comparing two different statistical analyses of the data. Seeds were obtained from artificial pollinations in the field: self-fertilization of hermaphrodites, and cross-fertilizations of both hermaphrodites and females. One-way analysis of variance using progeny type (selfed hermaphrodites, outcrossed hermaphrodites, and outcrossed females) as the treatment effect for each seed and seedling variable showed statistically discernable differences among progeny from different cross types. The significance of this type of ANOVA resulted from a reduced error term and positively-biased F ratios. A factorial design showed no significant differences due to type of progeny in seed mass, days to germination, leaf number, area, or biomass at six weeks of age. There were, however, significant differenes among seeds attributable to maternal parent for all seed and seedling variables. A higher proportion of seeds from outcrossed individuals germinated compared to that from self-fertilization. When the data were analyzed to include and partition all sources of variation, differences among offspring appeared during germination, rather than during later development. Seed mass, cross type, and sex of maternal parent all significantly affected the likelihood of germination; however, they had decreasing predictive power, respectively. Inbreeding depression in Silene vulgaris may help maintain gynodioecy; however, the pleiotropic effects of both nuclear and cytoplasmic genes for sex expression also may affect fitness and the maintenance of females.