Efficiency of honeycomb selection design in early segregating generation in ADT45 × Nona Bokra cross under salt stress

Abstract

Salt stress is a major abiotic stress that limits rice productivity worldwide including India. As modern rice varieties are salt sensitive, infusing salt tolerance through breeding is a viable farmer-friendly approach. Breeding salt tolerant rice varieties has been slow due to complexity of the trait and high Genotype x Environment interaction in the salt affected field. Selection practiced in such a situation using conventional selection method, in the presence of competition, would be misleading. On the otherhand, selection is effective in the absence of competition in honeycomb selection and counteracts the disturbing effects of competition on effectiveness of selection. The present study was conducted to test the efficiency of honeycomb selection design in early generation of a rice cross to study genetics of yield and practice selection. All the characters studied in both the design showed non normal distribution except for panicle length in CSD. All the characters studied in both the design had lower coefficient of variation, high mean and high standard deviation in the HSD compared to CSD. Large number of genes with duplicate epistasis governs days to flowering whereas panicle length and single plant yield are governed by few number of genes with complimentary epistasis. Twenty nine F2 plants each in CSD and HSD were selected based on mean and plant index (SPY), respectively. Plants selected in HSD recorded higher percentage of increase over base population compared to CSD and found HSD to be superior to CSD because of enhanced phenotypic expression in the former by eliminating confounding effects of negative correlation between yielding and competitive ability.