Genetic diversity and QTL-marker association analysis of rice germplasm for grain number per panicle and its contributing traits

Abstract

Rice is one of the leading cereal crops that consumed over half of the world's population. The number of grains per panicle is the main trait to decide grain yield potential of rice. Rice germplasm have rich diversity for panicle related trait. Hence, a study was undertaken to screen 77 diverse rice germplasm for grain number per panicle and its contributing traits. Mahalanobis' D 2 analysis was performed to study genetic diversity among the germplasm. Eight clusters were formed and cluster IV was found to be the largest cluster with 37 genotypes. Cluster V had 20 genotypes with the highest cluster mean value of 298 for the number of grains per panicle. Grain yield per plant and the number of spikelets per panicle were found to be the biggest contributor for total divergence. QTL linked markers were screened in diverse rice germplasm. Among the six QTLs screened, five QTLs were significantly associated with grain number per panicle and its relevant traits. For grain number per panicle the QTLs, Gn1a (0.1058), qGN 4.1 (0.117) and NGP 4 (0.062) recorded high R 2 values. Among the markers, Gn1a indel 3 (GN1a), NKSSR 04-19 (q GN 4.1), RM 6314 (NGP 4) and RM1183 (NOG 1) were identified as the most informative markers for utilization in marker assisted breeding programme. From this study, genotypes viz., Kallukar, CO52, IET 29504, IET 29506, RP-5594-97-5-1, MTU1360, ADT 54 possess high mean value for grain number per panicle and grain yield, linked with functional markers could be used as a donor in marker assisted breeding programme.