1985 Volume 54 Issue 1 Pages 1-8
Investigations were carried out to determine the appropriate concentration of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BA) for the regeneration of intact plants and multishoot formation from the apex culture of axillary-buds (0.25_??_0.3mm) of ‘Kyoho’ vines.
1. To enhance the survival rate, a preliminary test was performed using various modified Murashige and Skoog (MS) media. The survival rate of inoculated apex was highest (higher than 80%) in a modified MS medium containing one tenth amount of nitrogen, 0.1mg/l NAA, 1.0mg/l BA, 30g/l sucrose, and 7.0g/l agar. Therefore, this modified MS medium was adapted in this study.
2. The effect of BA was very marked in the stage from the greening and enlargement of inoculated plantlets to the development of shoots and multishoot formation (stages 1_??_3); The optimum concentration was found to be 1mg/l in all the stages. In view of the fact that supplementation with 1mg/l NAA resulted in callus formation from plantlets and inhibition of shoot formation, either the concentration of NAA should be lower than 0.1mg/l, or no NAA should be supplemented.
3. Supplementation with BA at the forth stage enhanced callus formation, but inhibited rooting from the basal part of shoots. This stage was, therefore, carried out without supplementing with BA. NAA promoted the elongation of shoots at a low concentration (0.05mg/l or less), making potting easy. Rooting rate was high, but the elongation of shoots were poor when supplemented with 0.1mg/l NAA or more. The rooted shoots were, therefore, transferred to a medium containing either no NAA or a low concentration of NAA to ensure elongation before potting.
4. Intact plants of ‘Kyoho’ vines were regenerated successfully from apex culture by supplementing a modified MS medium with NAA and BA.