ROLE OF YEAST EXTRACT IN THE GROWTH OF BLACK SEED CALLUS AND PRODUCTION OF SECONDARY METABOLISM COMPOUNDS

An experiment was conducted at the tissue-culture laboratory, Coll. of Agric.-Univ. of Baghdad during the period of 15/1 - 10/10/2012, to investigate the effect of yeast extract on the induction of black seed callus and its products of secondary metabolism. The callus was grown in the MS medium supplemented with the yeast extract Saccharomyces cerevisiae (Sac.) of three concentrations (0.4, 0.8 and 1.2) mg.liter(-1). The experimental design was complete randomized design. The results inducted that the best concentration of NaOCl for black seed sterilization was 6% for 15 minutes and the best combination of 2,4-D and kin to callus induction from the stems of black seed seedlings was the MS medium supplied with (3 and 1) mg liter(-1), respectively. The Sac concentration significantly increased the callus fresh and dry weights by 36, 227, 72, 48, 292 and 108% for sac (0.4, 0.8 and 1.2), respectively. The sac(0.8) treatment gave the highest concentration of Thymol (THY), Thymoquinone (TQ) and Thymohydroquinone (THQ). While the sac(1.2) gave the highest concentration of Trans-anethole (Trans.) compound.