濒危植物缙云卫矛繁育系统研究

运用花粉萌发、联苯胺-过氧化氢法、花粉—胚珠比、杂交指数和套袋实验等方法,对缙云卫矛(Eu-onymuschloranthoidesYang)花粉活力、柱头可授性及繁育系统进行了研究。结果表明缙云卫矛花粉-胚珠比为764~1340,杂交指数等于3,结合人工授粉和套袋实验结果可以确定该物种的繁育系统属于自交亲和,有时需要传粉者。根据套袋实验及实地观察可以推测该物种以风媒传粉为主。其花粉活力较高,持续时间较长,花粉质量可能不是导致该物种濒危的主要原因。其雌雄性功能表达具一定的重叠期,提高了同株异花授粉的几率,雌雄性功能表达在时间上的差异不是影响其结实率的主要原因。气候条件对传粉过程的限制可能是导致该物种濒危的原因之一。

Study on the breeding system of the endangered plant Euonymus chloranthoides Yang

Breeding system is theoretically considered as a significant factor which has the most apparent effects on population genetic structure. It is practically useful in plant breeding and conservation of endangered species. Euonymus chloranthoides Yang is an endangered plant species which is endemic to Chongqing. This paper,presents pollen viability,stigma receptivity,pollen-ovule ratio, out-crossing index, and fruit set under a serious pollination treatments of E.chloranthoides Yang. From these experiments,the pollen-ovule ratio(P/O)is about 764～1 340,and its out-crossing index=3. Combining with the result of emasculation,bagging and artificial pollination,the breeding system of this species was determined to be self-compatible and needs pollinators sometimes. In 1 to 3 days after its anther crazed,there were above 50% of pollen has viability,the most was 97% of pollen has viability,so its pollen quality may not be the major factor leading to the endangered status of this species. The expression period of sexual function is overlapped to a high degree(the mean synchronies of two populations are 0.797 and 0.788),and it increased the probability of geitonogamy. Therefore,the difference between the expression of sexual function is not the major factor which influences the ratio of seed-setting of E.chloranthoides Yang. The limit of climate to pollination may be an influencing factor to the endangered status of E.chloranthoides Yang.