Agronomic and molecular performance of rice lines carrying spikelet number and days to heading loci
Joko Prasetiyono, Tasliah, Nafisah, Ma’sumah, Chaerani, Supriyanta, Andari Risliawati, Kurniawan Rudi Trijatmiko and Mahrup
Abstract: Increasing rice production can be achieved by increasing spikelet number and shortening the flowering period. This study evaluated the agronomic performance, genotype stability, and molecular profiles of 14 rice lines derived from backcrosses of Conde—an Indonesian nationally released variety targeted for improvement—with IR64, which carries qTSN4, a locus that enhances spikelet number, or qDTH8, which shortens days to heading. Five Conde-qTSN4 lines (A8-5, A16-5, B6-2, B12-2, and B22-1) exhibited statistically increased total grains (both filled and empty) per panicle, while two Conde-qDTH8 lines (G64 and G142) matured earlier. AMMI and GGE biplot analyses identified Conde and three qTSN4 lines (A8-5, B12-2, B15-2) as stable across nine environments. Molecular analysis confirmed the presence of qTSN4 or qDTH8 alleles, with all lines carrying the Xa7 resistance gene. The qTSN4 and qDTH8 loci contributed to yield improvements of 3% and 12.5%, respectively, demonstrating their potential to enhance rice productivity in Indonesia.