Preliminary study on pollination ecology of Vitex negundo in Yantai, China

This paper aimed to compare the differences of pollination ecology between Vitex negundo var. heterophylla in China and Vitex negundo in India from the perspective of flowering phenology, breeding system and the diversity of flower visitors. Submicromorphology of pollen and stigma was observed by scanning electronic microscopy (Hitachi TM-1000). The pollen viability was estimated by TTC (2, 3, 5-triphenyl tetrazolium chloride) and the stigma receptivity was estimated by benzidine-H2O2. The main results were as follows: V. negundo var. heterophylla in China were basically same in terms of pollen viability, stigma receptivity, breeding systems and effective pollinators with Vitex negundo in India. However, due to differences in fauna and other ecological factors, the diversity of flower visitors is quite different. The species of flower visitors on V. negundo in India are more than that of V. negundo var. heterophylla in China. The pollen morphology of V. negundo var. heterophylla in China was also slightly different from V. negundo in India. Maybe it is the difference between V. negundo and V. negundo var. heterophylla.