西葫芦幼苗耐低温弱光生理指标分析

以西葫芦品种超越206（耐寒型）、特早王（中间类型）、早青一代（耐寒性弱）为试材研究了低温弱光对西葫芦幼苗生理指标的影响。结果表明：低温弱光胁迫下，POD和CAT活性升高，但SOD活性降低，可溶性糖与脯氨酸含量增加。各项指标在临界低温(10 ℃/5 ℃)比偏低温(15 ℃/10 ℃)处理时变幅大，偏弱光(50 μmol·m-2·s-1)比临界弱光(30 μmol·m-2·s-1)处理时变幅大，温度影响大于光照影响。SOD、POD、CAT活性与可溶性糖和脯氨酸含量显著或极显著相关。临界低温偏弱光胁迫（10 ℃/15 ℃，50 μmol·m-2·s-1）对西葫芦幼苗的生理指标有显著影响，可以作为西葫芦耐低温弱光性的鉴定指标。超越206比早青一代和特早王耐低温弱光，适宜日光温室冬春季节栽培。

Analysis of Physiological Index of Squash Seedlings in Tolerance to Low Temperature and Weak Light

Squash(Cucubita pepo L.)seedlings exposed to different low temperature and weak light were taken to investigate the effects on their physiological index.The results showed that POD and CAT activities increased,but SOD activity decreased,contents of soluble sugar and proline increased under the stress of low temperature and weak light.Each index showed greater change under crucial low temperature(10 ℃/5 ℃)than lower temperature(15 ℃/10 ℃),under weak light (50 μmol·m^-2·s^-1)than crucial weak light(30 μmol·m^-2·s^-1).Temperature has greater effects than light.SOD，POD and CAT activities and contents of soluble sugar,proline had significantly or very significantly correlation with each other,which can evaluate squash seedlings tolerance to low temperature and weak light.‘Chaoyue 206’is better than‘Zaoqingyidai’and‘Tezaowang’in tolerance to low temperature and weak light,so it is suitable to be cultivated in greenhouse in winter and spring.