Tissue Cultural Studies on the Maintenance and Multiplication of Parental Lines in Rape (Brassica napus L.) Heterosis Breeding Ⅱ. Effects of Media Constituents and Environment Conditions on the Organogenesis from Vegetative tissue Segments of Rape by in Vitro

This study was conducted to explore optimal culture conditions and medium constituents for inducing whole plants of Brassica napes L, through tissue culture by in vitro. The results obtained were as follows : Medium with 20 g/ℓ of sucrose showed 58% of whole plants induced but medium without sucrose did not. the addition of 0.2g/ℓ yeast extract to media produced 49% of whole plants which was better than that without yeast extract. Therefore, small amounts of yeast extract added to media promoted differentiation, The PH 6 was optimal for the differentiation and development of whole plants. The 61% of whole plants was induced at 26±1℃ being optimal for tissue culture of rape. Stems were the best in differentiation, followed by petioles, whereas leaves did not differentiate. B_5 medium was optimal for the development of whole plaints because of its higher rates than Murashige & Skoog medium. The B_5 medium containing 1.0 ㎎/ℓ NAA and 1.8 ㎎/ℓ benzyladenine showing 95% was the best in whole plants development. Thus, the growth regulators combined above would be optimal for organogenesis.