Control of Dioscorea alata microtuber dormancy and germination by jasmonicacid

Effects of appling exogenous jasmonic acid (JA) on the germination of Diosc orea alata L. microtubers were examined on Murashige and Skoog (MS) medium. Microtuber germination was promoted by JA (0.1 and 1 mu M) supplemented to the culture medium but higher concentrations (30 and 100 mu M) completely inhibited germination. When these inhibited microtubers were transferred to hormone-free medium, germination resumed. After transfer to greenhouse conditions, almost all plants (95%) from tuber s previously cultivated on MS medium with 100 mu M JA survived and all accl imatized plants had produced tubers after 8 months. It is concluded that de pending on JA concentration, both the germination and dormancy processes in D. alata microtubers were affected. The release from dormancy is easily ob tained by transferring dormant microtubers to hormone-free medium.