Biological interactions on Primula sieboldii

比较了北海道南部Hidaka地区破碎景观和本州中部山区超种群的20个三叶弓形虫种群的结实率和各种可能影响繁殖成功的生物和其他环境因素。虽然包括食草动物和病原体在内的多种生物因子影响植物的育性，但种群的结实率强烈依赖于种群规模和传粉者的可用性，这可以通过长舌大黄蜂皇后在花瓣上留下的爪痕来评估。在Hidaka地区调查的20个种群中，在少于4个基因的较小种群中，结实率可以忽略不计，而在较大种群中，种群平均结实率强烈依赖于传粉者的可用性，特别是在传粉者活动普遍较低的年份。三叶草离体母株上产生的种子不仅数量少，而且质量（即适合度）也明显低于附近有潜在交配对象的离体母株上产生的种子。

Seed set and various biological and other environmental factors potentially attecting reproductive success were compared among 20 P.sieboldii local populations in a fragmented landscape of Hidaka region, southern Hokkaido and also in a metapopulation of a mountainous region in central Honshu . Although various biological agents including herbivores and pathogens affected the fertility of the plants, seed set of the populations was strongly dependent on the population size and pollinator availability which can be assessed by craw marks left on the flower petals by long-tongued bumblebee queens. Among the 20 populations investigated in Hidaka region, negligible seeds were set in smaller populations consisting of less than four genets, while in larger populations, population mean seed set strongly depended on pollinator availability especially in the year with generally low pollinator activities. Not only quantity of the seeds, but also their quality, i.e., fitness of the seeds which were barely produced on isolated mother plants of P sieboldii are also significantly lower than those of the seeds from less isolated mother plants having potential mating partner(s) in their vicinity.