Evaluation of Salt Tolerance Mechanism and Study on Salt Tolerance Relationship of Different Salt-Tolerant Wheat Varieties

The physiological and biochemical indexes of different salt-tolerant wheat cultivars under salt stress are affected to different degrees. The changes in physiological and biochemical indexes in salt-tolerant wheat varieties are moderate, while salt-sensitive wheat varieties have bigger changes. In this article, through comprehensive utilization of germination and seedling indoor test morphological indexes, physiological and biochemical index, and output index, combined with the evaluation mechanism of wheat’s salt resistance, different salt tolerance types in the middle and lower reaches of the Yangtze River in Shandong province were studied; a collection of 100 wheat varieties and 11 wheat varieties planted over a large area were classified into three groups: strong salt resistance, medium salt resistance, and weak salt resistance. Comparative analysis of different wheat varieties’ salt resistance evaluation mechanism was performed, as well as the analysis of the germination rate of wheat varieties, coleoptile growth situation, emergence rate, protect wheat seeding rate, tillering rate, seedling height, root length, seedling dry weight, wet weight, number of leaves, plant growth situation, agronomic characters of the Na+/K+ ratio, and other physiological and biochemical indexes such as salt resistance index. The evaluation mechanism of salt tolerance and the relationship of salt tolerance of different wheat varieties were obtained. The results showed that there were significant differences in salt tolerance among the 100 wheat varieties at the germination stage. Among them, three varieties, YM (Yangmai) 25, YM (Yangmai) 24, and EM (Emai) 25, had the strongest salt tolerance at the germination stage, reaching the level of the salt tolerance variety DK 961, and the salt tolerance was in the first level, while NM 17, NM 23, and other 21 varieties reached the level of the salt tolerance. These 24 varieties with strong salt tolerance at the germination stage can be used to screen the salt tolerance of wheat planted in the saline soil of Jiangsu coastal beach.