桂花种子休眠和萌发的初步研究

Dormancy and germination of Osmanthus fragrans seeds

为了解桂花Osmanthus fragrans种子的休眠原因以及掌握解除休眠的最佳方法,对紫梗籽银桂'Zigeng Ziyin'种子种皮和种实的甲醇浸提液的生物测定和不同质量浓度赤霉素(GA3)处理后种子发芽率进行测定。结果表明:紫梗籽银桂种子的种皮和胚乳中均含有抑制白菜Brassica campestris籽萌发的物质,抑制作用随质量浓度增大而增加。综合前期研究结果,认为桂花种子的休眠不是外源休眠和综合休眠,而是由于由抑制物质引起的内源休眠。赤霉素处理结合低温层积可有效解除种子的休眠,其中以1000mg·L-1赤霉素浸种,低温层积75d的发芽率最高。

To detect reasons for dormancy and methods of breaking dormancy, a bioassay of a methanol ex- tract from Osmanthus fragrans ＇ Zigeng Ziyin＇ seed coats and endosperm as well as germination of seeds treated with Gibberellic acid （GA3） were studied. The cabbage seeds were germinated with methanol extract solution （0.10, 0.06, and 0.03 g·L^-1）, by three replications each treatment. And the osmanthus seeds were soaked in different concentrations （500, 1 000, and 1 500 mg·L^-1） GA3 for 48 hours, then stratified with low temperature, and every 15 days, taken out 30 seeds each treatment with four replications for germination. Results showed that the restraining substances were contained in the seed coat and endosperm, and the inhibitory effects became stronger as the extraction solution concentration increased. Integrating results from the prophase, we think that seed dormancy belongs to physiological dormancy. Soaking with 1 000 mg·L^-1 GA3 followed by cold stratification with sand for 75 d could raise the germination percentage and could be an effective method to overcome dormancy. [Ch, 4 fig. 15 ref. ]