变温层积处理对南方红豆杉种子生理生化特性的影响

Effect of Cold-warm-cold Stratification Treatment on Physiological and Biochemical Characteristics of Taxus chinensis var.mairei Seeds

脱除外被蜡质层的南方红豆杉种子,经低-暖-低变温层积结合植物生长调节剂及微量元素处理,120 d休眠解除.未层积处理的种子可供胚呼吸直接利用的可溶性糖等含量低.变温层积处理后,种子蛋白质、氨基酸和可溶性糖含量分别比对照提高了27.6%、80.0%和107.1%,脂肪含量降低了16.4%;种子脱氢酶、过氧化物酶和多酚氧化酶活性分别比对照提高了7.6%、129.3%和119.6%,蛋白酶活性降低了13.3%;解剖学特征表明,经变温层积处理,种子胚的发育渐进完善.实验结果提示种子贮藏物质特别是脂类物质的分解、转化和利用可能是南方红豆杉种子休萌解除的关键.

The primary study indicated that the seed dormancy of Taxus chinensis var. mairei was broken by combination of cold （4℃）-warm （23℃）-cold （4℃） stratification treatment with plant growth regulator and microelement for 120 days. Several physiological and biochemical characteristics of T. mairei seeds during cold-warm-cold stratification treatment was studied in this paper. Seeds without stratification treatment showed low soluble carbohydrate and starch, and the respiratory activity in early stage of the germination was limited as a result. The relative content of protein, amino acid and soluble carbohydrate increased by 27.6%, 80.0% and 107.1% respectively and the relative content of fat decreased by 16.4% after cold-warm-cold stratification treatment. The relative activity of dehydrogenase, peroxidase and polyphenol-oxidase increased by 7.6%, 129.3% and 119.6% respectively and the relative activity of protease decreased by 13.3%. The micro morphological character indicated that the embryo varied with treatment significantly. The stratification treatment embryo could develop into plant. The results showed that it was a necessary condition to break seed dormancy of T. mairei that lipids were turned into carbohydrate.