Abstract: MGBG [methylglyoxal bis(guanylhydrazone)], when added to the initial of callus subculture, promoted ethylene production in callus grawn in Bsh medium, and enhanced the ACC (1-aminocyclopropane-l-carboxylic acid) level and the ACC synthase activity both in the callus grown in Bsh medimn, and in the suspension cultures in Bsg liquid medium for induction of somatic embryogenesis. However, MGBG reduced the malonyl-ACC (MACC) level of the suspension tissues. The treatments of MGBG caused growth of the cultured tissues and induction efficiency of somatic embryogenesis to reduce. Moreover, the effects of MGBG was enhanced when it was added at induction medium of somatic embryogenesis. It could be concluded that this inhibitory effect of MGBG could be due to its promotion of ethylene, ACC levels and ACC synthase activity which has shown to inhibit somatic embryogenesis. The reduction of MACC level could be also involved in the MGBG effect on induction of the embryogenesis.

Key words: Methylglyoxal bis(guanylhydrazone), Medicago sativa, Somatic embryogenesis, Ethylene biosynthesis