苗期解除弱光胁迫后大豆恢复能力的生理评价

摘要

The objective of this study was to screen suitable evaluation indexes indicating the stress and recov-ery degree after shade stress,which would provide a theoretical basis for breeding soybean varieties and developing reasonable cultivation measures in intercropping system.Using two soybeans as material (C103,Gongxuan 1 )and setting the natural light(CK)and shade +light recovery treats by pot experiment,14 stress related physiological indexes of soybean including chlorophyll content,photosynthetic gas exchange parameters,chlorophyll fluorescence parameters,antioxidant enzyme activities and MDA content were measured on 0,2,4,7,10 days after light recovery and evaluated by gray relational grade analysis and hierarchical cluster analysis.The results indicated that each of the 14 traits,had significant difference between different soybean varieties or at different recovery stages after shade stress,and the correlation of different indicators and soybean recovery level also had significant difference (0.150 9-0.963 1).The traits with higher correlation degree to recovery index were Pn (0.907 3)and MDA (0.832 7), which presented lower variation than others.They were ranked the first category according to hierarchical cluster a-nalysis and could be used as key physiological indexes in evaluating the stress and recovery degree after light recov-ery.%通过分析大豆苗期解除弱光胁迫后恢复能力的生理评价指标，为套作大豆品种的选育及高产技术栽培提供理论依据。本研究采用2个大豆材料（C103、贡选1号），通过盆栽试验，设置自然光照（CK）和遮阴＋光照恢复处理，于解除弱光的第0、2、4、7、10d，对大豆叶绿素含量、光合气体交换参数、叶绿素荧光参数、抗氧化酶活性及丙二醛含量等14个生理指标进行测定，并采用灰色关联度分析、聚类分析等方法对各指标进行分析和评价。结果表明，解除弱光胁迫后，14个生理指标在不同大豆品种、不同恢复时间存在显著差异，不同指标与大豆恢复能力的关联度存在显著差异（0．1509～0．9631），其中净光合速率（0．9073）和丙二醛含量（0．8324）与恢复指数关联度较高，其关联度变异系数最小，稳定性最高，聚类分析将其分为第一类，可作为关键性生理指标用于评价大豆解除弱光胁迫后的恢复能力。