干旱胁迫及复水对浙江润楠幼苗生长与生理特性的影响

Effect of Drought Stress and Rewatering on Growth and Physiological Characteristics of Machilus chekiangensis Seedlings

采用温室盆栽和干旱胁迫的处理方法,研究不同程度干旱处理对浙江润楠Machilus chekiangensis生长和生理特性的影响。结果表明,随着干旱胁迫时间的延长,土壤自然含水量、叶片相对含水量、植株苗高净生长量和地径净生长量均呈下降趋势,SP含量、SOD活性和叶绿素a、叶绿素b、叶绿素a/b以及类胡萝卜素含量等指标总体呈先上升后下降的趋势,Pro含量和MDA含量则不断累积。复水后,干旱胁迫处理5 d的土壤自然含水量、苗高净生长量和SOD活性可恢复至对照组CK水平;干旱胁迫处理10~30 d的复水后幼苗SOD活性仍比CK高,叶片相对含水量、地径净生长量、SP含量、Pro含量基本可恢复至CK水平,MDA含量则降低,但各干旱胁迫处理的数值仍比CK高。各干旱胁迫处理的叶绿素a、叶绿素b、叶绿素a/b以及类胡萝卜素含量均变小,且各指标的最大值也都变小。综上分析可知,浙江润楠具有一定的抗旱性能。

The drought resistance of Machilus chekiangensis seedlings was identified and evaluated using simulated drought stress and rehydration in green house. The results were as follows： with the increase of stress time, soil water content, relative leaf water content, growth amount of net height and net ground diameter of seedlings decreased significantly. SP content, SOD activity, Chl a, Chl b, Car contents and Chl a/b increased at first, and then declined under severe drought, while Pro content and MDA content increased throughout the whole process. After rewatering, soil water content, net height of seedlings and SOD activity treated 5 days was basically restored to CK, and SOD activity treated during 10--30 days was higher than that of CK. The relative leaf water content, net ground diameter, SP content and Pro content were significantly restored to CK. MDA content decreased and the value of each drought stress was higher than that of CK. Chl a, Chl b, Car contents and Chla/b were all smaller, and the peak of each index also became smaller. Through analyzing the variation of these indexes, it was concluded that M. chekiangensis seedlings had a certain drought tolerance.