干旱对苗木萌芽期水分状况、ABA含量及萌芽特性的影响

WATER CONTENT ABA AND SPROUT CHARACTER AFTER TRANSPLANTING SEEDLING SOIL UNDER DROUGHT

采用 4种常见造林树种沙棘 (HippophaerhamnoidesL .)、油松 (Pinustabulaeformis)、刺槐 (RobiniapseudoacaciaL .)和杨树 (Populussimonii) ,研究水分胁迫下苗木移栽后萌芽过程中体内水分状况与ABA累积关系 ,探讨干旱使苗木致死的生理学机制。结果表明 ,土壤干旱导致苗木组织含水量、芽体生长速率、萌芽率及成活率显著下降 ;各树种在萌芽过程中其芽体和韧皮部中的脱落酸 (ABA)含量随土壤干旱程度的加重而升高 ,并与苗体组织含水量、萌芽率及成活率呈显著负相关 ;抗旱性强的沙棘和油松芽体和韧皮组织中ABA绝对含量比杨树和刺槐高 5～ 10倍左右 ;经统计分析发现 ,4种苗木的萌芽速度。

Relationships among water status, endogenous Abscisic acid (ABA) and sprout rate of 4 species of transplanting seedlings, locust (Robinia pseudoacacia L.), Chinese seabuckthorn (Hippophae rhamnoides L.), Chinese pine (Pinus tabulaeformis), poplar (Populus simonii) were analyzed. The main results are: water deficit made water content, sprout rate, sprout growth rate, and survival rate decrease notably. ABA in bud and phloem of species was increased by soil drought and there were interrelated notable negative relationships between ABA and water content, sprout rate and survival rate. ABA in bud and phloem of seabuckthorn and Chinese pine was 5-10 times higher than in locust and poplar. Statistical analysis revealed interrelated significant relationships between sprout rate, survival rate and phloem water content.