干旱胁迫对不同大豆品系酶类变化的影响

Effect of Drought Stress on Enzymes of Different Soybean Strains

选用来自同一杂交组合的4个不同类型品系,探讨干旱胁迫对不同大豆品系酶类变化的影响。于苗期和花荚期分别设正常供水和干旱胁迫两个条件,测定POD、SOD、CAT等与抗旱性相关的酶指标,同时进一步对花荚期SOD同工酶和酯酶同工酶做电泳分析,并对株重、株高、粒数、粒重、百粒重等农艺性状进行综合分析,还以隶属函数值对各个品系进行综合测评和抗旱级别的划分,进而对花荚期各种酶的活性与抗旱隶属函数值作相关和回归分析。花荚期不同品系SOD、POD、CAT的活性均呈上升趋势;采用抗旱隶属函数值的方法综合测评,得出不同品系抗旱性从强到弱的次序为:73-2(圆叶紫花)、73-1(尖叶白花)、73-3(圆叶白花)、73-4(尖叶紫花);且抗旱性强的品系,酶活性也高。干旱胁迫导致不同品系的酶活性均有增加,以清除体内自由基,保护质膜,增强品系抗旱性;在不同时期,活性增加程度不同,且酶活性与抗旱隶属函数值显著正相关。所以酶活性可以作为抗旱性的鉴定指标之一。

The objective of this study is to discuss effect of drought stress on changes of enzymes in different soybean strains. Four strains from the same cross were selected, these strains were 73- 1 （ sharp leaves and white flowers）, 73- 2 （round leaves and purple flowers） ,73-3 （round leaves and white flowers） ,73-4（ sharp leaves and purple flowers）. During seedling and flower-podding periods, two conditions of normal water supply and drought stress were set, and drought-relevant enzyme indexes such as POD, SOD and CAT, were determined. Simultaneously, electrophoresis analysis for SOD isoenzyme and Esterase in the period of flower- podding was conducted. Also, integrated analysis of agronomic traits such as plant weight,plant height, seed quantity,individual seed weight, 100-seed weight, and so on were applied. Different strains were comprehensively assessed and their drought- resistant classes were divided by subordinate function value. Activities of POD, SOD, and CAT all increased under drought stress during the flower-podding period. The order of drought-resistance was 73- 2 〉 73-1 〉 73-3 〉 73-4, and the most drought-resistant strains possessed highest enzyme activity. Under drought stress, all strains increase their protective enzyme activity to eliminate internal free radicals, protect integrity of plasmalemma, thus improving their drought resistance. The increasing extent of enzyme activity was distinct in different periods. In addition, activities of enzymes were significantly positively correlated with the values of the drought- resistant subordinate function. Therefore, activities of enzymes are able to be utilized as indexes for evaluating drought resistance.