Screening and characterizing of LHydroxyoroline resistant variants in Medicago sativa

Alfalfa seeds of Aohan and Longmu 801 were used as materials for seedling cultivation, whose explant was used to induce callus and treated with 200 mg/L NaN3 for mutation. The callus was cultured on medium with and without 8 mmol/L Hyp to select mutants. The mutants contained 2.84 times (Aohan) and 3.17 times (Longmu 801) of praline than the wild types. Meanwhile, their soluble sugar content were 1.56 (Aohan) and 1.76 times (Longmu 801) higher than the CK. POD enzyme activity was also significantly different compared with the wild type. PEG（Aohan）and low temperature（Longmu 801）treatments indicated that the mutants had stronger stress resistance (drought and cold) more adaptable to harsh environments.