Breeding for fertilizer-efficient rice is paramount. The succeeding research aimed to study the genetic makeup and selection procedure for tolerant rice genotypes in minimum fertilizer. The genetic material comprised 106 F5 rice lines and five check genotypes grown under optimum and minimum fertilizer conditions. The experiment layout was in an augmented design with five replications. The results indicated genotype-by-environment interactions significantly (p < 0.01) affected rice yield-related traits, specifically productivity. The identified rice lines totaled 26 through multi-trait genotype-ideotype distance index (MGIDI) analysis using 25% selection intensity. The heritability value in the optimal environment (0.725) was higher than in the minimum environment (0.628). Similarly, values for genetic advance (GA) and genetic advance as a percentage of the mean (GAM) in the optimal environment (1.160% and 18.680%) were higher than those in the minimum environment (0.659% and 13.158%). The geometric mean productivity (GMP), harmonic mean (HM), mean productivity (MP), and stress tolerance index (STI) exhibited a significant positive correlation with the average yield under optimum conditions (Yp) and minimum conditions (Ys). However, the stress susceptibility index (SSI) and tolerance index (TOL) showed a negative correlation with Ys, indicating selection based on the tolerance index identified the best lines, G27 and G66.
Rice (O. sativa L.), F5 populations, minimum fertilizer, selection, heritability, genetic gain, tolerance indices, yield-related traits
The study highlighted the use of the MGIDI method and tolerance indices (TOL, SSI, STI, MP, HM, and GMP) in identifying promising rice (O. sativa L.) genotypes better suited for low-fertilization conditions. These insights serve as a valuable resource for optimizing fertilizer efficiency to enhance sustainable rice production.