Pollen viability,stigma receptivity and pollinators of Weigela florida

Pollen viability of Weigela florida (Bunge) A.DC.was evaluated by TTC (2,3,5-triphenyl tetrazolium chloride),the stigma receptivity was estimated by benzidine-H_2O_2,the flowering dynamics,pollen-ovule ratio,morphology of stigma and pollen,and the pollinators were investigated on the field in situ.The main results were as follows:the pollen viability of W.florida was higher than 70% at the blooming day,and could last about 3 days.Three hours after blooming,stigmas were white,most of them split open and had receptivity,and the receptivity could last 2 or 3 days.There were 5.3±0.9 mm from stigma to anthers,so,it was difficult for W.florida to accomplish self-pollination in natural conditions.In the blooming day,there were abundant visitors on W.florida flowers especially at 7:00~10:00.At the second blooming day,the numbers of visitors decreased,and even more lower at the third day.Visitors most frequently seen were arranged in Hymenoptera,Lepidoptera,and Diptera.The Bombus sp.and Apis sp.were the most effective pollinators.