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. 1 Hydroxy-L-proline sensitivity of calli derived from seeds of HYP lines
and Nipponbare.
Fig. 2. Growth of calli derived from roots of regenerated plants.
-:Regeneration medium contained no Hyp
+:Regeneration medium contained 10-3M Hyp
References
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.