关键词: 繁殖特征, 花期交叠现象, 种子产出率, 榕小蜂

Abstract: Ficus microcarpa, a common ornamental species in Fuzhou, was a kind of monoecious fig species. A total 85 F. microcarpa plants in Fuzhou were chosen to study their pollination biology. The syconium growth of F. microcarpa can be divided into five phases: pre-female phase, female phase, inter-floral phase, male-phase and post-floral phase. F. microcarpa has both long style and short style female flowers. The stigma is long and curved, independent from each other, and does not form joint stigma platform that benefits to fig wasps' pollination and spawning. Its male flower matures late. F. microcarpa can continuously produce the figs year-round. Fruiting peaks occur during April to August, and each tree can produce 1-4 crops in a year. The growth duration of F. microcarpa syconia from pre-female phase to post-floral phase was closely associated with the hydrothermal conditions. In the dry and cold season, that is from October to March, figs grow slowly, and the developmental cycle usually lasts for 3-6 months. However, in the wet and hot season, that is from April to September, figs grow faster, and the developmental cycle is finished in only 1-2 months The fig development is inter-tree and intra-tree asynchrony, and the sexual phase overlaps frequently. The foundress number of F. microcarpa during female phase is dominated by only 1-2 wasp, which makes the small and numerous syconia effectively obtain wasps, does not only significantly raise pollination efficiency of wasps, but also ensures high ratio of fruiting in syconia. This may be the result of co-evolution of the fig-wasp mutualism. Seventeen kinds of wasps were found in syconia of F. microcarpa in Fuzhou , and they belong to six families (subfamily) of Chalcidoidea. Among them, Eupristina verticillata of Agaonidae was the only species-specific pollinator for F. microcarpa , and it dominated in the structure of wasp community. F. microcarpa had low seed output rate, with only 13.64%, probably due to the lack of joint stigma platform, and high ratios of NPFWs (non-pollinating fig wasps) in both species and quantity. F. microcarpa may increase the seed output through increasing annual flower phases (product batches) to ensure its breeding. The results of this study would provide a scientific basis for the urban greening and biodiversity conservation in tropical rain forests.

Key words: reproductive characteristics, sexual phase overlap, seed production rate, fig wasp