EMS‐induced mutations in common vetch (Vicia sativa L.) and two mutants without anthocyanin accumulation showing increased cold tolerance

Common vetch (Vicia sativaL.) is a leguminous plant used as forage and cover crops. A protocol of ethyl methanesulfonate (EMS)-induced mutations was established in the present study, based on analysis of seed germination and emergence rate, seedling growth and abnormal plant percentage as affected by combinations of EMS concentration and treatment time. Treatment of seeds with 0.1% EMS for 9 and 12 hr or 0.5% EMS for 6 and 9 hr led to 43%-66% normal plants, which was suggested to be used for EMS-induced mutations in common vetch. The wild-type common vetch showed red with accumulation of anthocyanins in winter, and two lines showing separation of anthocyanin accumulation (labeled as A(+)) and without anthocyanin accumulation (labeled as A(-)) plants were selected from M(2)plants induced by EMS in the field. The A(-)plants showing green color had higher plant height and fresh shoot weight than the A(+)plants during wintering, with lower ion leakage after freezing treatment, indicating that the green mutants (A(-)) had increased cold tolerance. Compared to A(+)plants, the green mutants had significantly increased ascorbate (AsA) level in response to low temperature treatment. The results suggest that the increased AsA level under low temperature was associated with the increased cold tolerance in the green mutants.