【摘要】 模拟秋季温度和光照变化,对2个紫花苜蓿品种进行降温-低温处理的抗寒锻炼,研究抗寒锻炼后苜蓿半致死低温、生物量、含水量、根冠比的变化及其相关性。结果表明:抗寒锻炼可降低苜蓿根、叶的半致死低温,并增加根、叶半致死低温的差异。抗寒性强的肇东根、叶的半致死低温对降温处理的响应大于抗寒性弱的赛迪10。抗寒锻炼过程中,肇东表现为持续一致的变化,降温处理后地上生物量增加减缓,地下生物量逐步增加,含水量降低,根冠比降低减缓,低温处理加速以上变化;赛迪10表现为起落式变化,降温处理后地上生物量大幅增加,地下生物量降低减缓,含水量降低,低温处理后地上生物量停止增加,地下生物量缓慢降低,含水量增加。苜蓿生长性状与半致死低温的相关性顺序是:地上部含水量>地下生物量>地下部含水量>根冠比>地上生物量,其中地上部含水量、地下生物量、地下部含水量与半致死低温的相关性达到显著或极显著(P<0.05或P<0.01),可为苜蓿抗寒性鉴定的候选指标。更多还原

【Abstract】 In this study, two alfalfa varieties with different cold resistance were treated with cooling-low temperature to investigate the changes of semi lethal low temperature(LT₅₀), biomass, water content, root shoot ratio and their correlation. The results showed that cold hardening could reduce the LT₅₀ of alfalfa root and leaf, and increase the difference of LT₅₀ between root and leaf. The LT₅₀ of roots and leaves of Zhaodong with strong cold resistance was greater than that of Sadie 10 with weak cold resistance. During cold hardening, Zhaodong showed consistent changes. After cooling treatment, the growth rate of aboveground biomass slowed down, while underground biomass gradually increased, water content decreased, the rate of root shoot ratio decreased, and low-temperature treatment accelerated the above changes. While Sadie 10 showed a rise and fall type change. After cooling treatment, aboveground biomass increased significantly, underground biomass decreased slowly, water content decreased. After the low temperature treatment, aboveground biomass stopped increasing, underground biomass decreased slowly, and the water content increased. According the correlation with LT₅₀, the sequence of alfalfa growth traits was: aboveground water content>underground biomass>underground water content>root/shoot ratio>aboveground biomass. The correlation among aboveground water content, underground biomass and root water content reached significant level and above（P<0.05）, which could be recommended as a candidate index for alfalfa cold resistance identification.更多还原