保湿冷藏对湖南山核桃种子萌发及生理的影响

Effects of moisture-preserved refrigeration and natural dehydration on the seed germination and physiology of Carya hunanensis

为了探索湖南山核桃(Carya hunanensis Cheng.)种子的萌发及生理特性,采用自然脱水和保湿冷藏后播种的方法,对湖南山核桃种子的萌发特性及其顽拗性和萌发过程中种子内脂肪、蛋白质、淀粉、水溶性糖、脱落酸(ABA)、赤霉素(GA4+7)、玉米核苷(ZRS)、生长素(IAA)的含量变化进行了研究。结果表明,湖南山核桃种子采收后立即播种就能发芽,脱水干燥后丧失发芽力;保湿冷藏可在一定的时间内延长湖南山核桃种子的寿命,同时也能提高发芽率,增加形成多胚种的比例,但超过60 d发芽率显著下降;未脱水的湖南山核桃种子无论经过保湿冷藏与否,播种后种子中的脂肪、淀粉、蛋白质、ABA都快速降解,GA4+7、ZRs和IAA含量都迅速增加,这种生理响应的启动在保湿冷藏20d后的种子中提前了。湖南山核桃种子不耐脱水,具有顽拗型种子的明显特征,没有休眠特性。

In order to explore the characteristics of the seed germination and physiology of Carya hunanensis Cheng.,the methods of natural dehydration and refrigeration to preserve moisture were used to study the effects on fat,protein,starch,water-soluble sugar,ABA,GA4＋7,ZRS,IAA during germination of the seed and the recalcitrant of the seed.The results showed that seed was able to germinate immediately by direct seeding after harvest.The seed lost germinating ability after dehydration.Refrigeration to preserve moisture could extend the life of Carya Hunanensis Cheng.seeds to a certain period,improve the germination rate,and increase the proportion of the polyembryonic seeds.The rate of germination decreased significantly after 60 d-refrigeration to preserve moisture.The fat,starch,protein,and ABA in the seeds without dehydration was degradation rapidly whether refrigerated or not,but the contents of GA4＋7,ZRs and IAA were increased rapidly.However,the physiological response of the seed after refrigeration started earlier.The seed of Carya hunanensis Cheng.was intolerantly dehydrated.The seed had obvious recalcitrant property,no dormancy character.