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.