凤仙花属(Impatiens)植物具有极为广泛的多样性和类型各异的特化传粉者, 被誉为“双子叶的兰花”, 受到众多传粉生物学家的关注。本文以海南特有种海南凤仙花(Impatiens hainanensis)为研究对象, 对3个不同海拔梯度的种群进行了开花生物学特性和开花物候、花器官结构、花粉活力和柱头活性、传粉者种类和访花行为及繁育系统的比较研究。结果表明: 单花花期4.10 ± 0.46 d, 雄性期和雌性期分别约为3.15 ± 0.24 d和0.95 ± 0.36 d; 种群开花峰期在8月初, 高海拔种群的花期高峰相对滞后。低、中海拔种群花粉活力呈现先升高后下降的趋势, 以开花第2 d花粉活力最高; 高海拔种群花粉活力随开花时间推移逐渐下降; 柱头活性随开花时间的推移而增强, 高海拔种群开花各天次均较低、中海拔种群低。主要传粉昆虫为黄黑无垫蜂(Amegilla leptocoma)和绿条无垫蜂(A. zonata), 低、中海拔种群以黄黑无垫蜂为主, 高海拔种群以绿条无垫蜂为主。未观察到自动自花授粉和无融合生殖现象, 人工授粉能明显增加坐果率(75-90%), 自然坐果率在高海拔种群相对较低(40-60%), 说明存在较强的传粉者限制。海南凤仙花的保护需要同时关注其有效传粉者的保护, 促进有效传粉昆虫在不同海拔种群之间的往来, 保证种群间的花粉流与种子流, 维持海南凤仙花的种群遗传多样性与有效种群大小。

The genus Impatiens, known as “dicotyledonous orchids”, is of great interest to pollination biologists because of its extremely wide diversity and different types of specialized pollinators. In this study, populations of Impatiens hananensis, endemic to Hainan Island, distributed at three different altitudes were studied. Floral phenology, floral structure, pollen viability and stigma activity, floral visitors and their behavior, and the breeding system were determined. Results showed that the average life span of a single flower was 4.10 ± 0.46 d; the male and female flowers lasted 3.15 ± 0.24 d and 0.95 ± 0.36 d, respectively. The species’ flowering peak was in early August, and the high altitude population flowered the latest. The pollen viability of a single flower appears in the trend of first increased then decreased with the flowering time went on, and reached to the highest on the second flowering day in low and middle altitude populations, and which declined gradually with the flowering time went on in high altitude population. Stigma activity generally rose as flowering time went on, but this measure was lower in high altitude population on different flowering days. The main pollinators were Amegilla leptocoma and A. zonata; A. leptocoma was the main visitor in low and middle altitude populations while A. zonata was in the high altitude population. We observed no automatic self-pollination or apomixis in I. hainanensis, and hand-pollination increased the fruit set (75-90%), compared to the natural situation (40-60%). This lower natural pollination success rate was especially true in the high altitude population where pollination was most limited. Therefore, conservation work with Impatiens hainanensis should protect both habitats and effective pollinators of I. hainanensis in order to promote gene flow via pollinators and seed movement among populations at different altitude via pollinators, and maintain the population genetic diversity and effective population size of Impatiens hainanensis.