盐胁迫对诱变小麦种子萌发及幼苗生理特性的影响

本研究以化学诱变获得的小麦突变体为材料,研究了盐胁迫对小麦发芽及幼苗生长的影响。结果表明,随着NaCl浓度(0、100 mmol.L 1、200 mmol.L 1、300 mmol.L 1、400 mmol.L 1)的增加,小麦的发芽率、发芽指数、活力指数、芽长、根长、芽鲜重和干重、根鲜重和干重均呈下降趋势,300 mmol.L 1NaCl为4种小麦(3个突变体、1个对照CAO811CK)发芽能力的临界盐浓度,其中突变体CAO8113K优于其他小麦材料。在300 mmol.L 1NaCl胁迫下,随着时间延长(12 h、24 h、48 h、96 h、192 h),4种小麦材料幼苗可溶性蛋白含量、丙二醛(MDA)含量逐渐增加,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性呈上升趋势。采用模糊数学隶属函数法对可溶性蛋白、MDA、SOD、POD、CAT 5项生理指标进行综合评价,4种小麦材料耐盐潜力由强到弱依次为CAO8113K>CAO811CK>CAO8114K>CAO8112K,CAO8113K突变体小麦材料表现出较强抗盐性,与发芽指标检测结果基本一致。

Influence of salt on seed germination and seedling physiological characteristics of mutagenic wheat

Studies have shown that salt stress could influence normal seed germination. Generally, the greater the concentration, the smaller is the germination rate. Seed germination research under salt stress has laid the critical basis for characterizing the ability of plant salt tolerance. This research used chemical mutagenic wheat materials to study seed germination and seedling growth under salt stress. The results showed that as NaCl concentration increased (from 0 to 100 mmol·L^-1, 200 mmol·L^-1, 300 mmol·L^-1 and 400 mmol·L^-1), percent germination, germination index, vitality index, seedling height, root length, seedling fresh/dry weight and root fresh/dry weight decreased. Also 300 mmol·L^-1 of NaCl concentration was the critical salt concentration for the germination of three mutagenic wheat materials and CAO811CK (control). Compared to the other wheat materials, the CAO8113K excelled. Under salt stress, with prolonged duration of the test, the contents of soluble proteins and MDA of the four wheat materials under 300 mmol·L^-1 of NaCl stress gradually increased and so were activities of SOD, POD and CAT. Using a comprehensive empirical distribution function and fuzzy membership function, five physical indices were selected (including soluble protein, MDA, SOD, POD and CAT) to evaluate wheat salt-tolerance capacity. The order of salt-tolerance capacity of the four tested mutagenic wheat materials was as follows: CAO8113K > CAO811CK > CAO8114K > CAO8112K. This was basically the same as the observations in the earlier studies. The mutagenic wheat CAO8113K had better resistance than the other wheat materials.