南蛇藤花粉和柱头的生物学特性研究

Bionomics of Pollen and Stigma of Celastrus orbiculatus Thunb.

以南蛇藤花粉和柱头为研究对象,用日立TM-1000扫描电镜(SEM)观察花粉和柱头形态;用TTC(2,3,5-triphenyl tetrazolium chloride)法测定不同贮藏温度对雄花花粉活力的影响;用固体培养基萌发法测定不同温度下雄花花粉的萌发率。结果表明:南蛇藤花粉粒呈长球形,赤道观细长椭圆形,极面观近三裂圆形,具三孔沟,网状雕纹。南蛇藤雌花、两性花的柱头形态及不同发育期的变化规律相似,而雄花柱头形态明显区别于雌花和两性花的。不同的贮藏温度对雄花花粉活力的影响差异明显,贮藏温度越高,花粉失活越快,说明低温利于花粉贮藏。南蛇藤雄花花粉萌发的最适温度约25℃。

Celastrus orbiculatus Thunb is widely grown in China. It is a member of traditional medicinal and ornamental plants. Bionomics of pollen and stigma of this cuhivar under specified condition have never been reported up to now. The pollen and stigma morphology of C. orbiculatus was studied with the aid of scanning electron microscopy. Pollen viability of male flowers was determined by 2,3,5-triphenyl tetrazolium chloride （TTC） after 36 h duration at -20℃ , 4℃ , 15℃ , 25℃ , 35℃ and 50℃ , respectively. A medium for pollen germination, composed of 50 g · L- 1 sucrose, and 0.3 g · L- 1 boric acid solidified with 6 g · L-1 agar, has been optimized in this work. Subsequently, the temperature effect on the germination of pollens of male flowers served as an indicator. The basic shape of the pollen grains in both male and hermaphrodite was exceedingly similar, which was described as prolate, elongated-elliptical in equatorial view, sub-3-1obed-circular in polar view, and had 3 colporates. The morphological changes in the female and hermaphrodite stigma organs were similar in different development periods, but different from that of male. The result of different storage temperatures demonstrated that low temperature greatly contributed to pollen storage. In this study, we found 25℃ was optimum for pollen germination, while germination decreased at 20℃ and 30℃. This study observed morphology of pollen and stigma, and investigated the effect of storage temperature on pollen viability as well as the influence of varying temperatures on pollen germination and pollen tube growth. Such information would allow a deeper understanding of how specific factors impact on the effective pollination period in C. orbiculatus, and moreover provide more valuable information for other species＇ theoretical study.