Exploring component traits of biomass and yield in Indian rice mini-core germplasm

Rice is an essential food grain for more than half of the global population. To ensure food security, improvement in the genetic gain in yield is necessary. This necessitates identification and utilization of genotypic variation among rice germplasm for biomass and yield component traits. In this regard, 188 rice genotypes were evaluated under field conditions during the kharif season in 2016 (experiment 1) and 2017 (experiment 2). The genotypes were categorized based on biomass, grain yield, and harvest index in experiment 1, and significant variability was observed in these traits. During experiment 2, these genotypes were characterized based on growth rates and yield component traits. Physiological growth rates (RGR and NAR) showed significant variation among the rice genotypes. Component traits of yield viz., biomass and Harvest Index (HI), showed high heritability (H²), and genotypic coefficient of variation (GCV) was higher for biomass as compared with HI. HI showed positive and significant correlation with yield across the phenological group of genotypes, while biomass showed a significant and positive correlation with yield only in short duration genotypes (90–125 days). Multi-trait genotype-ideotype distance index (MGIDI) analysis led to the identification of 8 superior genotypes i.e., Sahbhagi Dhan, Maudamani, Seratoes, BAM4510, GP-145-37, Bamoia, Dular and MTU1010 for their use as donors for different component traits in improvement of yield in rice. The genetic variation found among rice germplasm in physiological growth rates and component traits can be further used for gene pyramiding in future breeding programs for breaking the yield barrier in rice to provide higher yield productivity.