Identification of promising genotypes and marker-trait associations for panicle traits in rice

Among various panicle traits, total number of spikelets, total number of grains and total grain filling % can be considered as main traits for determining yield in rice.Query To identify the genotypes with promising grain number at different positions of the panicle, a set of 72 germplasm comprising landraces and varieties were evaluated for 28 panicle traits across four environments. Correlation and regression analysis of 28 panicle traits highlighted the role of secondary panicle traits in contributing to the total grain yield. Three promising genotypes, viz. Badshahbhog, Ganjeikalli, Jeerigesanna for high SS (≥ 177), GS (≥ 143), and two genotypes, BR4_10, MO1 for GFS (93%) were identified. Interestingly, the same genotypes exhibited high STOT, GTOT and GFTOT. From G × E interactions, which won where view of GGE biplot, revealed that the genotypes Badshahbhog, Ganjeikalli, Jeerigesanna have won in different environments for grains total, and genotype BR4_10 for total grain filling %. Screening of the reported markers for cloned yield genes (Dep1, Ghd7, Ghd8, PROG1 and OsSPL14) in 72 genotypes revealed 19 significant associations for 10 panicle traits in four environments with R² ranging from 5.4 to 20.2%. High significant association of Ghd8 with SUS was detected with 20.2% R² value. The promising genotypes with high number of STOT, GTOT, GFTOT, SS, GS and GFS identified from the present study can be deployed in the breeding programmes of rice yield improvement.