FAN, SHUGUO*, CHENGYE LIANG, AND HONGXIAN LIU. South China Institute of Botany, Academia Sinica, Guangzhou 510650, P. R. China. - Identification of restoring and maintaining relationship of male sterile variants of rice (Oryza sativa L.) cultured in vitro.
Pollen free type (PFT) genic male-sterile (GMS) line Nanguangzhan had
turned into WA type-like CMS line. The restoring and maintaining
relationship of NT1 and NT2 (two typical abortion type male sterile
variants from Nanguangzhan somaclones) was similar to that of WA type.
NT1 had been backcrossed with its maintainer lines for 10 generations
and kept sterile all the way. This might be the first report of this
kind of mutant derived from somaclones of rice which had turned into
CMS from GMS. There were four typical abortion type (TAT) variants in
R1 regenerated plants which derived from Minghui 63 (coded S11-14),
IR26 (coded 26-9-15-7), Zhenshan 97B (coded B2-9-15-4), and Baoyuan A
(coded 28-18), whose restoring and maintaining relationship was the
same as that of WA type. These variants had been backcrossed with
their maintainer lines for five generations, and kept sterile all the
way. The restoring and maintaining relationship of one of TAT variants
which derived from Minghui 63 (coded S10-2) was completely different
from that of WA type, HL type and BT type, viz. S10-2 was crossed with
IR24, IR26, IR36, Ce 64, Taiyin 1 and Minhui 63 and kept sterile;
while it was crossed with Zhenshan 97B, Erjiuai 4B, Hongyuan B and
Baoyuan B and turned into fertility, both pollens and seeds were
fertile. S10-2 had been back-crossed with its maintainer lines for
five generations, and kept sterile all along. Five male-sterile
variants, which derived from IR26 (coded 26-9-24-11,TAT), Hongyuan A
(one was coded 24-1, stained abortion type (StAT); the other was coded
S14-1, TAT) and Baoyuan A (one was coded 28-5, spherical abortion type
(SpAT); the other was coded 28-19, TAT), kept sterile continuously for
five generations when they were backcrossed with 10 fertile parents
(Zhenshan 97B, Erjiuai 4B, Hongyuan B, Baoyuan B, IR24, IR26, IR36, Ce
64, Taiyin 1 and Minghui 63).
Key words: cytoplasmic male sterility (CMS), in vitro culture, indica, japonica, Oryza sativa L., restoring and maintaining relationship