Restoration of male sterility of wild abortive cytoplasmic male sterility (WA-CMS) was studied
from Thai Rice varieties. Pollen fertility, Spikelet fertility of F1 hybrid of the cross between IR58025A and
studied variety and restorer genes Rf4/PPR9 locus were examined. The result revealed that Chai Nat 1
(CNT1), Suphan Buri 1 (SPB1), Pathum Thani 1 (PTT1), RD47, RD49 and Look Daeng Pattani (LDP)
varieties were classified as restorer line (R line), whereas Hom-nin (HN), Khao Dawk Mali 105 (KDML105),
Red Hom Mali (RHM) and Nahng Mon S-4 (NMS-4) varieties were classified as maintainer line (B line).
The molecular markers linked to restorer genes at Rf3 and Rf4, PPR9 and PPR10 genes, loci were
investigated from F2 populations of IR58025A x CNT1, IR58025A x PTT1, IR58025A x RD47 and
IR58025A x LDP. The restoration of Male Sterility of CNT1 and RD47 were controlled by PPR9 and Rf3
with duplicated dominant epistasis interaction. The restoration of male sterility of PTT1 was controlled by
Rf4 locus which are PPR9 and PPR10 genes. The PPR9 gene was main gene while PPR10 gene was modified
gene. The analysis of F2 population (IR58025A x LDP) showed that there was other restorer gene might play
a role in LDP variety. However, PPR9 gene and Rf3 could restore male sterility of LDP. This grouping
information and the interaction between male sterility restorer genes could be further used in the development
of other Thai rice varieties.