基于叶片生理指标的小麦芽期耐盐性评价

Comprehensive evaluation of salt tolerance in wheat based on physiological indexes of leaves at germination stage

关键词:  小麦, 芽期, 生理指标, 耐盐性, 综合评价

Key words:  wheat, germination stage, physiological index, salt tolerance, comprehensive evaluation

摘要:

土壤盐渍化严重影响小麦生产,提高小麦耐盐性是应对土壤盐渍化的主要生物途径之一。小麦芽期亦是对盐分较为敏感的时期,小麦芽期耐盐性的强弱对盐碱地小麦种植至关重要。为探讨利用叶片生理指标进行小麦芽期耐盐性评价的可行性,该文以沧麦6005及其73个叠氮化钠诱变家系为试验材料,在超纯水和40%人工海水条件下,对芽期叶片中脯氨酸、可溶性糖、总蛋白和可溶性蛋白含量及过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性等进行测定,利用主成分分析和聚类分析进行小麦芽期耐盐性综合评价。结果表明:(1)在40%人工海水盐胁迫下,小麦芽期叶片中脯氨酸和可溶性糖含量增加,总蛋白和可溶性蛋白含量降低。POD活性增强,而CAT和SOD活性减弱。(2)主成分分析中第1和第4主成分是小麦芽期叶片耐盐的酶活响应因子,第2和第3主成分是小麦芽期叶片耐盐的渗透调节因子。(3)在耐盐性评价中,沧麦6005芽期耐盐性鉴定等级为2级(耐盐),耐盐等级鉴定为1级(高耐)的家系为SAM1、SAM49和SAM59,这与田间生产实践经验一致。综上结果表明,POD、CAT和SOD的活性以及脯氨酸和可溶性糖含量可作为小麦芽期耐盐性评价的叶片生理指标。该研究结果可为利用叶片生理指标进行小麦芽期耐盐性评价提供参考。

Abstract:

Soil salinization seriously impacts wheat(Triticum aestivum)production. Improving salinity tolerance is one of the main biological approaches responding to the problem. The germination stage is also sensitive to salt, and the salt tolerance at the germination stage is very important for wheat planting in saline-alkali land. In order to explore the feasibility of using physiological indexes of leaves to evaluate salt tolerance of wheat at germination stage, CM6005 and its 73 sodium azide mutagenesis families were used as experimental materials. The contents of proline, soluble sugar, total protein and soluble protein, as well as the activities of peroxidase(POD), catalase(CAT)and superoxide dismutase(SOD)in the leaves were measured under the conditions of ultra-pure water and 40% artificial sea water, and principal component analysis and cluster analysis were used to evaluate the salt tolerance of the wheats. The results were as follows:(1)Under 40% artificial sea water salt stress, the contents of proline and soluble sugar increased, while those of total protein and soluble protein decreased. The activity of POD increased, however, the activities of CAT and SOD decreased.(2)In principal component analysis, the first and the fourth principal components were two factors of the response of salt-tolerant enzyme system, and the second and third principal components were the main two factors of osmotic adjustment of salt tolerance in wheat leaves at the stage of germination.(3)In the evaluation of salt tolerance, the salt-tolerant grade of CM6005 was 2(salt tolerance), and that of the lines was 1(high salt tolerance), which were SAM1, SAM49 and SAM59. All the above results indicate that the activities of POD, CAT and SOD as well as the contents of proline and soluble sugar can be used as physiological indexes to evaluate the salt tolerance of wheat at germination stage. These results can be used as a reference for the evaluation of salt tolerance in wheat based on physiological indexes of leaves at the germination stage.