干旱对沙棘休眠、萌芽期内源激素及萌芽特性的影响

EFFECT OF SOIL DROUGHT ON ENDOGENOUS HORMONE AND SPROUT CHARACTER IN DORMANCY AND SPROUT PERIOD OF SEABUCKTHORN SEEDLINGS

以 2a生中国沙棘为试验材料 ,研究了土壤干旱胁迫下沙棘苗木水分生理状况 ,内源GA1 3 及ABA水平与萌芽率的关系 ,结果表明 :土壤干旱胁迫导致苗体含水量、水势、自由水含量下降 ,显著提高冬季休眠与春季萌动期的内源ABA水平而降低内源GA1 3 含量 ,GA1 3 ABA降低 ,较晚达到萌动所需的调控阈值 ,萌芽延迟。重度胁迫下苗木延迟达 2 5d且萌芽后生长缓慢。长期土壤中度干旱条件下沙棘苗萌芽期亦略有延迟 。

Relationship between water status, endogenous hormone and sprout rate of 2 years old China seabuchthorn under water deficit was analyzed. The main results are: water deficit made water content, free water, water potential and endogenous GA 1/3 of seabuckthorn seedlings decreased, while endogenous ABA level increased obviously during dormancy stage in winter and sprout period in spring, so ratio of GA 1/3 /ABA droped and came to threshold value later. As a result, the germination day delayed, especially that of seedlings under serious water deficit was postponed even for 25 days. Besides, seedlings grew slowly after sprout. Seabuckthorn suffered slight injure from a long time of medium soil water stress and sprout date was also delayed a few days and growth after sprout was restrained to a small extent.