温度对薄壳山核桃种子萌发的影响及其机制初探

摘要

将薄壳山核桃的完整种子与去壳种子在不同温度条件下进行发芽试验,并测定了温度对淀粉酶活性的影响,菜豆素(淀粉酶抑制剂)对完整种子萌发的影响,以及不同温度对种子萌发初期中,淀粉、可溶性糖、粗脂肪、可溶性蛋白和游离氨基酸变化的影响.结果表明:薄壳山核桃种子在30、35℃条件下,种子萌发率分别为84％、82％,显著高于15、25和40℃3个温度下的情况,且所需的萌发时间较15、25℃条件下更短;因此薄壳山核桃种子适宜的萌发温度为30～35℃的高温条件,而超过该温度区间容易对种子造成伤害.同时,生理研究的结果显示,15～30℃时,温度越高,薄壳山核桃种子淀粉酶活力也越高,而淀粉酶活性抑制剂能够显著降低薄壳山核桃种子在30℃中的萌发率,这表明在一定温度范围内,温度变化可改变淀粉酶活性,从而调控薄壳山核桃种子萌发;同时,其它生理指标测定表明,糖类的代谢与蛋白质的代谢在种仁响应温度变化的过程中具有重要的作用.%A germination test of complete,shelled Carya illinoinensis seeds at different incubation temperature.And during the initial germinating stages of pecan seeds,the soluble sugar content,starch content,fat content,soluble protein content and free amino acid content was determined at different temperatures.Results showed that the germination percentages were 84％ and 82％ at 30℃ and 35 ℃ respectively,which were significantly higher than that at 15℃,25℃ and 40℃ and need less germination time.However,high incubation temperature is harmful to pecan seeds,so the optimal incubation temperature is 30 to 35 ℃ for pecan seed(especially for pecan seeds in low vigor);At 15-30 ℃,the higher the temperature,the pecan seed amylase activity is also higher.And the amylase activity inhibitor can significantly reduce the germination rate of Pecan seed at 30 ℃.This shows that in a certain temperature range,the temperature can change the activity of amylase,thereby regulating pecan seed germination.In addition,physiological results shows that soluble sugar content and soluble protein content play a important role in pecan seed germination in respond to different temperatures.