Seasonal changes in pollen limitation and femaleness along the snowmelt gradient in a distylous alpine herb, Primula modesta

摘要: Flowering phenology of alpine plants is strongly determined by the timing snowmelt, and conditions pollination widely distributed vary greatly during their flowering season. We examined reproductive success distylous herb, Primula modesta, along snowmelt gradient under natural conditions, compared it with result artificial experiments. In addition, compositions visit frequencies pollinators to flower P. modesta were period. The pin thrum growing at same site have an equal ability produce seeds if a sufficient amount legitimate pollen grains are deposited on stigma surface. However, seed-set was often (even not always) restricted limitation, functional gender biased female male, respectively, associated sites. These variations ascribed resource limitation nor morph ratio but seasonal changes in situations, replacement pollinator types from long- short-tongued resulted unidirectional transfer long stamens (thrum plants) styles (pin plants). specialization may enhance evolution dioecy heterostyly, severe cause breakdown heterostyly into homostyly. To consider evolutionary pathway heterostylous plants, accumulation empirical data required demonstrating how phenological synchrony between decided what degree this relationship stable over years, estimates selection gene flow individual plants.