低温弱光对红芸豆幼苗生长及生理生化特性的影响

Effects of low temperature and week light on growth and physiological and biochemical characteristics of red kidney bean seedlings

【目的】通过测定红芸豆幼苗生理生化指标,研究抗低温弱光胁迫的机制,并比较两个红芸豆品种的耐低温弱光性.【方法】以红芸豆为材料,测定分析低温弱光胁迫对幼苗生长及生理生化指标的变化.【结果】低温弱光胁迫抑制幼苗的生长,其中,小红芸豆株高、茎粗、叶面积在胁迫处理7 d后较对照分别降低19%,18%和15%,‘英国大红芸豆’分别较对照降低13.2%,16%和13%.生理生化分析结果表明,低温弱光胁迫下,2个品种幼苗叶绿素含量和PSⅡ的最大光化学效率F_v/F_m在处理7 d后达到最低,‘小红芸豆’的下降幅度较为显著;超氧化物歧化酶SOD、过氧化物酶POD、过氧化氢酶CAT活性均呈现先升高后降低,且‘小红芸豆’下降幅度更大;在胁迫处理期间抗坏血酸过氧化物酶APX活性及谷胱甘肽GSH含量一直呈下降趋势.【结论】红芸豆幼苗通过抗氧化酶系统抵御低温弱光胁迫;相比‘小红芸豆’而言,‘英国大红芸豆’具有较强的低温弱光适应性.

【Objective】 To determine the physiological and biochemical indexes of red kidney bean seedlings,to study the mechanism of low temperature and week light stress resistance,and to compare the low temperature and week light resistance of two cultivars of red kidney bean varieties.【Method】 Red kidney bean was used as material to determine the changes of seedling growth and physiological and biochemical indexes under low temperature and week light stress.【Result】 Low temperature and week light stress inhibited the growth of Red kidney bean seedlings.Among them,the plant height,stem diameter,and leaf area were reduced by 19%,18%,and 15%,respectively,compared with the control after 7 days of stress treatment,and British red kidney beans was decreased by 13.2%,16% and 13%,when compared with Red kidney bean.Physiological and biochemical analysis showed that under low temperature and week light stress,the chlorophyll content of the two cultivars and the maximum photochemical efficiency of PSII,F_v/F_m,reached the minimum after 7 days treatment,and Red kidney bean decreased significant.The activity of superoxide dismutase,peroxidase and catalase increased firstly and then decreased,and Red kidney bean decreased significantly.The ascorbate peroxidase activity and glutathione content decreased during the stress.【Conclusion】 Red kidney bean seedlings are protected against low temperature and low light stress through antioxidant enzyme system.Compared to Red kidney bean,British red kidney bean has stronger adaptability to low temperature and weak light.