Studies On Systematics For Six Species Of Impatiens L. And Pollination Biology Of Impatiens Reptans (Balsaminaceae)

Plant systematics for six species of ImpatiensL. endemic to China and pollination biology of Impatiens reptans have been studied for the first time. Following the results researched.1. There are some differences in morphology of six species. But they are easy to be impacted by environment and have more variability. Sometimes it is difficult to use these characteristics to identify Impatiens L. that have numerous species.2. According to the general characteristics of leaf epidermis for six species of Impatiens L. under the SEM show that: they have some difference in crest and stoma among of them. The observation results of seed surface for six species under the SEM show that the characteristic of seed surface such as the crest of seed capsule has significant difference among species of ImpatiensL. , which displays that the latter is more reliable than the former as the proof of taxonomy because the latter have more diversity than the former among these six species.The study of characteristics for six species of impatiens L. in leaf epidermis and seed under SEM have enriched the systematic data of Impatiens L. ,which displays much significance both in taxonomic research and in discussion of syst ematic relationships.3. Primary pollinators of Impatiens reptans are honey-bees and bumble-bees. Secondary pollinators are diurnal hawk moths and butterflies. Bombus briviceps and Bombus sp. are nectar gatherers. The mean nectar sugar concentration is 29.5%. The proport ion of seed is 86. 5%. Percentage seed germination under controlled conditions is 23.1 %. Distances that seeds are ejected ranged from 0.58-1.17 m. The distances that pollenspread is 29cm. Pollen viability is highest on the day of anthesis and thereafter decreased. Ratios of pollen/ovules (P/O) rang from 958. 8-970. 6. I. reptans reproduces by means of cross-pollination, and I. reptans may be self-compatible.4. The reason of narrow distributing and the coordinated evolution relation between I. reptans and pollinators have been discussed. Its dependence on a specialized habitat, a narrow environmental niche, a low percentage of seed germination and habitat loss, etc. could be reasons for its limited distribution and endemism. Flower with long spur selects pollinators with the long proboscis. During the long period of co-adaption, they have promoted its evolution respectively.