倭性種および正常種イネカルスの生長におけるジベレリン要求性について

抄録

Effect of gibberellic acid (GA₃) on the growth and organ formation in rice callus tissues of the dwarf varieties (Tan ginbozu, Sankei-10, Kotake tamanishiki, Murasaki daikoku, Waisei shinriki) and normal varieties (Ginbozu, Te-Tep, Norin-8) was studied using the modified Linsmaier and Skoog's medium, contajLning yeast extract with l0-⁵ or l0-⁷ M of 2, 4-D. The following results were obtained. (1) The callus growth of Tan ginbozu, which is a natural dwarf mutant of Ginbozu, was promoted by GA₃ only in the medium with l0-⁷ M of 2, 4-D. However in the other two dwarf varieties, Sankei-1O and Waisei shinriki, the growth was promoted in the both medium with l0-⁵ M and l0-⁷ M of 2, 4-D. On the contrary, GA₃ did not represent any promoting effect on the growth of Murasaki daikoku and all of the normal varieties used, rather affecting inhibitively.These data indicate the presence of varietal differences in GA₃ response and of GA₃-2, 4D interaction among eight varieties. (2) 0rganogenesis was observed in callus tissues of eight varieties on the medium with l0-⁷ M of 2, 4-D. Shoot formation was mostly prevented by 5×10-⁷ M of GA₃, and by 5×10-⁵M completely. Higer concentrations of GA₃ than those necessary for the inhibition of shoot were required to inhibit the root formation. (3) When subcultured in the medium with l0-⁵ M of 2, 4-I) for 14 passages and more, the growth of Tan ginbozu was vigorous rather than that of Te-Tep. The promotive effect of GA₃ on the growth of Tan ginbozu, which had been indicated at 3th-4th passage, disappeared entirely in long term culture beyond the 14th passage. The organ formation in cultures at 15th-16th passage reduced about 30 per cent in Te-Tep and disappeared in Tan ginbozu. (4) The inhibitive effect of GA₃ on the organ formation appeared with the concomitant to the inhibition of callus growth in Te-Tep and to the promotion of the growth in Tan ginbozu. Accordingly, the inhibitive effect of GA₃ on organ formation, observed similarly in both dwarf and normal varieties, seems to depend on the different activities from the GA₃ effect concerning to callus growth.