Abstract: In response to the phenomenon of large number of flowers and low fruiting rate in wild medicinal plant Daphne tangutica Maxim, wild populations of this plant were used as experimental subjects to observe its flowering phenology, morphological changes of flowering organs, pollen vigor and stigma fertility, and combined with the determination of pollen-ovule ratio (P/O), out-crossing index (OCI) and observation of flower visitor behaviors to reveal its breeding system and the limiting factors for its low fruiting rate. The results showed that:D.tangutica was hermaphroditic, inflorescence with terminal or axillary heads, flowering period was from May to June, group flower period 17~22 days, single inflorescence period 8~11 days, and single flowers period 7~9 days;Pistils mature before stamens, stigma pollination was strongest when florets were waiting to open, pollen vigor was strongest when florets were in full bloom;The determination of the P/O, OCI and the observation of flower visitors showed that D. tangutica was predominantly heterozygous, with some self-crossing affinities and most required effective pollinators such as Apis cerana, Bombus trifasciatus, and Bombus grahami. Studies have shown that the period of highest stigma fertility did not meet the period of maximum pollen vigor, the slender corolla tube required pollination by effective pollinators, low pollen dispersal during the flowering period, weak heterosis competitiveness and low self-fertility, as well as the low number and variety of effective flower visiting insects may be the main reasons for the low fruit set rate of D.tangutica. The study could provide a theoretical basis and practical foundation for the sustainable use of Zushima medicinal resources by planting and breeding D.tangutica on a large scale and with high quality.

Key words: Daphne tangutica Maxim, Flowering phenology, Pollen vitality, Stigma receptivity, Breeding system

摘要： 针对药用植物唐古特瑞香（Daphne tangutica Maxim）野生植株花多果少、坐果率低的问题，以唐古特瑞香野生种群为试验对象，观察其开花物候、花器官形态变化、花粉活力、柱头可授性等特征，并结合花粉-胚珠比（P/O）、杂交指数（OCI）的测定，访花者行为观察，揭示其繁育系统类型及坐果率低的限制因素。结果表明：唐古特瑞香为两性花，顶生或腋生头状花序，花期5-6月，群体开花持续17~22 d，单花序花期8~11 d，单花花期7~9 d；雌蕊先于雄蕊成熟，单花待开时柱头可授性最强，盛开时花粉活力最强；P/O和OCI的判定以及访花者观察显示其以异交为主，部分自交亲和，多数需要如中华蜜蜂（Apis cerana）、三条熊蜂（Bombus trifasciatus）、灰熊蜂（Bombus grahami）等有效传粉者。柱头可授性与花粉活力的最强时期不遇，细长的花冠管需要有效传粉者授粉，盛花期散粉量不高，异交竞争力弱和自交亲和度低，以及有效访花昆虫的数量和种类少等因素可能是造成唐古特瑞香开花量大坐果率低的主要原因。本研究结果为今后规模化、优质化人工繁育唐古特瑞香及祖师麻药材产量提升提供理论依据和实践基础。

关键词: 唐古特瑞香, 开花物候, 花粉活力, 柱头可授性, 繁育系统