No evidence of sex-differential pollen limitation at the flower level in the gynodioecious Gypsophila repens infected by Microbotryum violaceum

Because in gynodioecious species females are expected to be more pollen limited than hermaphrodites, we tested for sex-differential pollen limitation at the flower level, comparing fruit production and fecundity between open-pollinated and hand-pollinated flowers of Gypsophila repens ( Caryophyllaceae) over two years. No sex difference in pollen limitation was found. Hand-pollination increased fruit and seed production in the first year of the study but not in the second, and it actually decreased fruit set in the latter year, although overall fecundity was higher in that year. Ovule number differed between years, with perfect flowers containing more ovules in the second year. Gypsophila repens harbors the anther smut fungus Microbotryum violaceum, which infects and sterilizes many species of Caryophyllaceae. In G. repens, however, some infected plants are capable of seed production, although their fecundity is far lower than that of healthy plants. Seed production was not pollen limited even with the high percentage of infected individuals that could reduce the quantity of pollen available at the population level.