| In three-line hybrid rice system, development of parental lines by backcrossing and early generation testing for combining ability is a method used for developing CMS lines (A line) and restorer lines (R line) simultaneously. In this study F3 progenies from 15 crosses of maintainers (B line) were backcrossed to their respective A lines, and 6 crosses and 46 isogenic lines produced. Completely sterile backcross progenies were found in 3 crosses, i.e., IR79156A//IR79156B/CNT1, IR80156A//IR80156B/IR46R and IR80156A//IR80156B/SPR1. Concurrently three new CMS lines, PTT08001A, PTT08002A and PTT08003A were developed. They were then crossed with 5 testers or restorer lines, i.e., RD31, SPR1, CK81, CK120 and CK168. The resulting 15 crosses of F1 hybrid were... |
