关键词: 小花鸢尾, 花部结构, 花粉胚珠比, 杂交指数, 繁育特性

Abstract: Through the specific field observation of Iris speculatrix， its outcrossing index， pollen vitality and stigma receptivity， the ratio of pollen and ovule， artificial pollination and bagging were investigated to understand the flower feature， blossom dynamic and breeding system. Results showed that under the natural climate of Hangzhou， the flowering stage of populations was about 35 d from May to June， and the majority of plants kept blooming in 8th May to 20th May. The flowering stage for individual plant was 3-6 days. The life span of a single flower was about 3 d. The flowers， setting on the same inflorescence， were monoecism. Male and female flowers mature at the same time， and the distance between anther and stigma was about 3 mm. The out cross index（OCI）was 4， and pollen\|ovule ratio（P/O）was 552. Taking the results of the emasculated， bagged and artificial pollination experiment together， it indicated that Iris speculatrix flower is a mixed\|crossing system with out\|crossing affinity as the main breeding form and concomitance out\|crossing. Artificial pollination on fruit set rate was higher than the natural pollination. It was confirmed that under natural conditions， the reproductive system of Iris speculatrix was affected by floral organ structure and environmental factors.

Key words: Iris speculatrix, floral syndrome, pollen\, ovule ratio；cross\, breeding index, breeding characters