Relation between level of autumn dormancy and salt tolerance in lucerne (Medicago sativa)

Experiments were conducted to study the relationship between autumn (fall) dormancy rating (FDR) and salt tolerance of lucerne (alfalfa, Medicago sativa L.). Seeds of eight cultivars with different FDRs (range 2.0–10.2) were germinated in a growth chamber under five concentrations of NaCl (range 0–1.2%). A subordinate function value method was adopted for comprehensive evaluation of salt tolerance of the lucerne cultivars. Seed germination rate and germination potential, and seedling electrolyte leakage, shoot length, root length, fresh weight, root : shoot length ratio, Na+ and K+ concentrations and K+ : Na+ ratio were used as the indices of evaluation. Under 1.2% salt treatment, salt-tolerance ranking of the cultivars was WL656HQ > WL440HQ > WL712HQ > WL525HQ > WL343HQ > WL319HQ > WL363HQ > WL168HQ, with respective FDRs of 9.3, 6.0, 10.2, 8.2, 3.9, 2.8, 4.9 and 2.0. The results of this study show that non-dormant cultivars were generally more salt tolerant than dormant cultivars.