Unravelling genetic variability for moisture stress tolerance in Indian mustard and identification of high breeding value donor lines

Abstract

Aim: Identification of high breeding value donor lines harbouring tolerance to moisture stress from diversity stock of 443 genotypes of Brassica juncea. Methodology: Germplasm stock of 443 Indian mustard (Brassica juncea L.) genotypes, comprising introgression lines, land races, old cultivars and advance breeding lines, were evaluated under two environments viz., irrigated and rainfed conditions to check the variability for yield and related traits. Statistical software META-Rver 6.0 (Multi Environment Trial Analysis using R) was used for computation of Best Linear Unbiased Predictions, Analysis of Variance (ANOVA), Genetic Correlations and Heritability. Drought susceptibility index and per cent seed yield reduction under rainfed conditions were used as indicators to determine moisture stress tolerance in genotypes. Results: The variability for moisture stress tolerance has been unravelled in a diverse genetic stock of Brassica juncea under two environments: irrigated and rainfed. For high prediction accuracy, the ranking of genotypes was done based on Best Linear Unbiased Predictions for seed yield and its component traits. PBR-378, RGN-329, RB-73, RB-50 and PBR-422 and Giriraj were identified as moisture stress tolerant genotypes. One land race Sahib 36 and three introgression lines viz., MCP 12-211, PTJ-3-69 and MSC-3 have also been identified as potential genetic resources for moisture stress tolerance. Principal component analysis based on biplots depicted specific distribution of variables for each environment. Interpretation: This study led to the identification of potential donors for moisture stress tolerance with high predictive accuracy. Low drought susceptibility index and high breeding value in a land race and three introgression lines derived from Erucastrum cardaminoides, B. tournefortii and B. carinata emphasized their utilization as potential genetic resources to breed for moisture stress tolerance in B. juncea.