POLLEN APERTURE POLYMORPHISM AND GAMETOPHYTE PERFORMANCE IN VIOLA-DIVERSIFOLIA

Pollen aperture polymorphism is studied in Viola diversifolia, where a ll plants produce three- and four-apertured pollen grains. We tested w hether there are genetic differences among plants for the proportions of the different pollen morphs, and whether the morphs differ in gamet ophytic performance. Results show that the more apertures a pollen gra in has, the more quickly it germinates but that few-apertured pollen g rains have faster growing pollen tubes and longer life expectancies. T he proportions of the different pollen morphs, together with pollen tu be growth rates, may be inherited traits based on differences among ma ternal families. These results suggest that the different pollen morph s are favored in different pollination ecology situations. The product ion of several pollen morphs by the same individual could therefore be evolutionarily advantageous.