Pollination Biology and Breeding System of Melastoma dendrisetosum

To investigate the pollination characteristics of Melastoma dendrisetosum C. Chen,the flowering phenology,the pollinators,their behavior,the frequency of pollinator'visiting and climate condition were observed. Besides,the pollen viability,the stigma acceptability,P / O( pollen / ovule rate) and the breeding system of M. dendrisetosum were examined,which was studied in Diaoluo National Nature Reserve,Hainan Province,China. The results showed that M. dendrisetosum is typically heteranthery. The flowers of M. dendrisetosum come into blossom at 5: 30-8: 30 a. m.,into ful1-blown at 8: 30-9: 00 a. m. and into petal-shut at 7: 00 p. m. The florescence of individual flower and population flowers were 12-14 hours and 36 ± 2 days respectively. There was no nectar in the flowers. The species of pollinator were Xylocopidae,Anthophoridae,Formicidae,Syrphidae and etc. The most effective pollinator was carpenter bee. The field experiments indicated that the fruit sets were significantly high in both artificially out-crossed and self-pollinated flowers,while no fruit set was observed in bagged emasculated flowers and the unpollinated bagged flowers. These indicated that there were no self-compatible,no self-pollination and agamospermy in this species. Pollinators were necessary for it. The breeding system of M. dendrisetosum was a typical facultative inbred type. The relative reproductive success( RRS) was 0. 035,pollen and pollinator limitation were the most important limiting factors to M. dendrisetosum.