深山含笑传粉生物学研究

Pollination biology of Michelia maudiae

关键词:  深山含笑  花部综合征  繁育系统  传粉生物学

Key words:  Michelia maudiae  floral syndrome  breeding system  pollination biology

摘要:

为明确深山含笑(Michelia maudiae)的传粉生物学特性,该文以西华师范大学校园内的深山含笑为研究材料,采取野外观察法记录了深山含笑的开花动态、访花者及访花频率; 用游标卡尺法,测定了深山含笑的异交指数(OCI); 用醋酸洋红法,测定了花粉胚珠比(P/O); 用套袋和人工授粉法,测定了深山含笑的繁育系统。结果表明:(1)深山含笑为早春开花植物,其种群花期为2～3月,持续30 d左右,单花花期5～6 d; 在单花开放初期,最内层的花瓣未绽开,是适应潮湿或多雨的环境而保护花药与柱头免受雨水的冲刷,提高雌雄性适合度,确保繁殖成功的一种策略;(2)深山含笑的有效传粉者为蜜蜂,访花时间集中在晴朗天气的中午;(3)深山含笑的异交指数(OCI)等于5,花粉胚珠比(P/O)为2 933±50;(4)深山含笑为雄蕊先熟,柱头可授性在开花第2～3天达到最高;(5)套袋和人工授粉表明深山含笑为兼性自交和异交授粉,其中异交授粉的座果率和结籽率显著高于自交授粉。早春开花的深山含笑,其传粉者为单一的蜜蜂,繁育系统为异交,部分自交亲和,结果为引种栽培、良种选育等提供依据更好地利用和保护此资源奠定基础。

Abstract:

To study the pollination biology of Michelia maudiae,and provide theory basis for cultivation and artificial cross breeding of M. maudiae,the M. maudiae was studied in this paper which was grown in China West Normal University. The flowering dynamic,the visitors of flowers and the visitation frequency were recorded by field observations. The outcrossing index(OCI)was determined by vernier caliper. P/O was estimated by aceto carmine method. The breeding system was tested by the bagged and artificial pollination experiments. The results were as follows:(1)The M. maudiae was flowering in early spring,the flowering span of the population and single flowering was approximately 30 d and 5-6 d,respectively. In the early period of single flowering,the inner petals did not open. It aimed at adapting to the wet or rainy environment in order to protect anthers and stigmas from rain erosion,which was the strategy that improved the female and male fitness as well as ensures the reproductive success;(2)The bee was the effective pollinator of M. maudiae,which was visited in the sunny weather at noon;(3)The outcrossing index(OCI)and the pollen- ovule ratio(P/O)was 5 and 2 933±50,respectively;(4) M. maudiae was protandrous,which stigma receptivity reached the highest vitality during the flowering period of the 2nd or 3rd day;(5)The bagged and artificial pollination experiments showed that M. maudiae could be self-pollination and cross-pollination,and fruit-set and the seed-set of cross-pollination were significantly higher than the self-pollination. In conclusion,M. maudiae was an early spring flowering plant,bee was only the pollinator,the breeding system of M. maudiae was outcrossing which was partly self-compatible. The results could promote for using and protection the resources of M. maudiae.