S. Mori 1, H. Hasegawa 2, K. Nakamura 1, H. Nakanishi1 and M. Murakami1
1) Faculty of Agriculture, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto, 606 Japan; 2) Radiation Center of Osaka Prefecture, Shinke-cho, Sakai, Osaka, 593 Japan
Somatic variants so far reported in cereals are limited in number, and not all plants regenerated from variant cell lines have retained their particular characteristics. This note deals with the characterization of calli derived from the seeds of hydroxy-L-proline (Hyp) resistant mutants.
The isolation procedures for the HYP mutants and the culture conditions of calli have been reported by Hasegawa and Inoue (1983) and Mori et al. (1985). Briefly, calli were initiated from the seeds of the HYP mutants and the original variety (Nipponbare), respectively, and were maintained in Linsmaier and Skoog (1965) medium supplemented with 10-5 M 2,4-D. Shoot formation was induced on the same medium containing 10-7 M of auxin, 5x10-5M of kinetin, and 5 g/l yeast extract.
The difference in HYP resistance between HYP-calli and original variety's callus was most evident in culture with 10-3 M Hyp (Fig. 1). The resistance of the HYP-calli was more readily maintained by subculturing them in the presence of HYP than in its absence. The regeneration rates of HYP-calli in the presence of Hyp were almost the same as those in the absence of Hyp. The calli derived from the roots of explants regenerated from HYP-calli retained the Hyp resistance (Fig. 2).
Fig. 2. Growth of calli derived from roots of
-:Regeneration medium contained no Hyp
+:Regeneration medium contained 10-3M Hyp
Hasegawa, H. and M. Inoue, 1983. Induction and selection of hydroxy-L-proline resistant mutants in rice. Jpn. J. Breed. 33:275-282.
Linsmaier, E.M. and F. Skoog, 1965. Organic growth factor requirements of tobacco tissue cultures. Physiol. Plant. 18: 100-127.
Mori, S., H. Hasegawa, K. Nakamura, H. Nakanishi, and M. Murakami, 1985. Genetic analysis for hydroxy-L-proline resistant mutants in rice. (in Jap,) Jpn. J. Breed. 35 Suppl. 1: 150-151.