南方红豆杉种子生物学特性研究

Study on the Biological Characteristics of Taxus chinensis var.mairei Seeds

[目的]研究南方红豆杉种子的形态特征和萌发特性。[方法]以当年采收的南方红豆杉种子为试材，通过测定其形态指标、生活力及发芽力分析了其形态特征和萌发特性。[结果]种子呈坚果状，紫褐色，先端有突起的短钝尖头，种脐呈椭圆形。种子长为3．78～5．84mm，直径为3．84～5.86min，平均含水量为8．5％，千粒重为65．048g。种子由种皮、种胚和胚乳构成，种皮重量占完整种子重量的51．83％。新鲜南方红豆杉种子的种胚长约1．3～1．9mm。有生活力种子的比例为77％，无生活力和空粒种子的比例分别为21％和2％。层积8个月后，200mg／L赤霉素溶液浸泡处理的种子发芽率最高，达71．8％；流水处理的种子发芽率次之，为61．5％；自然层积处理的种子发芽率最低。f结论]南方红豆彩种子具有一定的侏眠特性．赤垂素浸泡时箕萌发有明显的促进作用．

[ Objective ] The purpose was to study the morphological characters and germination characteristics of Taxus chinensis var. mairei seeds. [ Method ] With mairei seeds harvested in the current year as tested materials, their morphological characters and germination characteristics were analyzed through measuring their morphological indices, vitalities and germination ability. [ Result ] The seeds were puce and pyreniform, had excrescent, short and blunt acrocephalia on their tops and their hila were oval shape. The length, diameter, average water content and 1 000-seed weigbt of the seed were 3.78 - 5.84 and 3.84 - 5.86 ram, 8.5 % and 65. 048 g resp. The seed was composed of seed coat, seed embryo and endosperm and the weight of seed coat account for 51.83% in the weight of whole seed. The lengths of seed embryos in the fresh mairei seeds were about 1.3 - 1.9 ram. The proportions of seeds with and without vitalities and empty seeds were 77% , 21% and 2% resp. After the seeds had been stratified for 8 months, the germination rate of the seeds which had ever been soaked in 200 mg/L GA3 solution was highest and reached 71.8% ; that of the seeds which had ever been treated with flowing water was secondary, being 61.5% ; that of the seeds which were stratified naturally was lowest. [ Conclusion ] The mairei seeds had certain dormancy characteristic and soaking in GA3 solution had obvious promoting effect on their germination.