关键词: 湖南报春苣苔, 传粉生物学, 繁育系统, 花部特征, 熊蜂

Abstract: For rational development and utilization of the wild germplasm resources of Primulina hunanensis，the role of the floral syndrome and breeding system on its sexual reproduction process was evaluated. The flowering phenology，floral features，and flower-visiting insects of P. hunanensis were recorded by field observation. We analyzed pollen viability and stigma receptivity，pollen/ovule ratio，and hybridization index，combined with artificial pollination experiment to test its breeding system. The result showed：(1) P. hunanensis flowered from May to July，with a flowering period of about 40 d and a single flowering cycle of 3–8 d. When the flowers were just open，the pollen was the most energetic（> 90%）in the flowering period，and the stigma was inactive，indicated that pistil and stamens of P. hunanensismatured at different times. After flowering，the growth of the stamens of P. hunanensis almost stopped，but its pistil continued to elongate，indicating that the pistils and stamens had different spatial positions. (2) The ratio of pollen and ovule was 518.36. The hybridization index was 5，indicating the breeding system of P. hunanensis was outcrossing，partial self-compatibility and demanded pollinators. The seed setting rate of P. hunanensis was not 0，and there was no apomixis in the bagged and emasculation experiment. (3) Many kinds of flower-visiting insects were surveyed in the P. hunanensis population. During the flowering period，Bombus sp. was the most effective pollinator which was adapted to its floral syndrome. (4) Under field condition，the fruit setting rate of P. hunanensis was higher. Asexual reproduction occurred in the population of P. hunanensis，maintaining the population as a reproductive compensation mechanism.

Key words: Primulina hunanensis, pollination biology, breeding system, floral syndrome, Bombus sp.