Stability of some of rice genotypes based on WAASB and MTSI indices

Abstract

Ten rice genotypes were evaluated in a randomized complete block design with four replications in three regions of Iran during three cropping seasons. Likelihood ratio test (LRT) was shown the significant effects of genotype and genotype by environment interaction (GEI). Scree plot indicated the first three components explained 81.24% of GEI variation. Mosaic plot partitioned total sum of squares (TSS) and indicated genotype and GEI effects illustrated 52.72% and 47.28% of TSS, respectively. Heatmap plot also exhibited variations in the grain yield of genotypes across environments. The best linear unbiased predictors (BLUPs) of grain yield showed that G2, G5, G4, G10 and G6 had a higher prediction than the overall grain yield. The nominal yield plot indicated G4, G5, G6 and G10 had a small contribution in GEI and were more stable genotypes. In the fourth quarter of grain yield vs the weighted average of absolute scores (WAASB) biplot, G2, G5 and G10 were highly productive and stable. Based on a weight of 50:50 for grain yield and stability, G5, G6, G2, and G3 had the highest WAASBY values and were determined as stable genotypes. In WAASB/GY ratio plot, it is observed that G5, G6, G2, and G3 had the highest WAASBY values and were deyermined as stable genotypes. Factor analysis based on WAASBY values of all of the traits identified three factors with a cumulative variance of 79.35. Based on the multi-trait stability index (MTSI), G6 and G3 were selected. In conclusion, G5 was superior to all genotypes and can be used to determine the best cropping manangement in agronomic research experiments and for the introduction of new cultivars.