Genotype x Environment interaction using AMMI and MTSI analysis for growth and yield attributes of radish (Raphanus sativus L.) under high temperature stress conditions of North Indian plains

Thirty genotypes of Asiatic radish including nine released varieties were evaluated for four traits in six envi-ronments (sowing dates) during summer 2021 at Punjab Agricultural University, Regional Research Station, Bathinda, India. All the six sowing dates fall in summer to expose plants to varied degree of high temperature stress and included E1 (15 March), E2 (15 April), E3 (15 May), E4 (15 June), E5 (15 July) and E6 (15 August). The data were subjected to statistical analysis using Additive Main effects and Multiplicative Interaction (AMMI) and Multi-trait stability index (MTSI) models. The genotype (G) and environment (E) variances were significant for all traits. The contribution of environment to total variance was the highest for root weight (60.2%), plant weight (59.6%) and shoot weight (43.6%) whereas for shoot weight the contribution of genotype was the highest (45.0%). The G x E interaction (GEI) was significant for all traits and it was partitioned into two interaction principal components (IPCA 1 and IPCA 2). Both IPCA 1 and IPCA 2 were significant for three traits and their cumulative contribution to GEI variance was 79.9% for shoot weight, 83.4% for plant weight and 96.4% for marketable yield. However, for root weight only IPCA 1 was significant and explained 66.0% of the interaction variance. The residual variance was non-significant for all traits. The values of environmental means for various traits resulted in the identification of E1 and E6 as rich and others as poor environments. Three genotypes viz., G3 (Palak Mooli), G9 (RL-19-1) and G11 (RL-2210) were identified for poor environments based on marketable yield. One genotype viz., G9 was suitable for rich environment based on plant weight, root weight and shoot weight. Four genotypes viz., G5 (RL-9-1), G9, G17 (LSR-1-1-HP) and G3 were selected as stable due to their lower MTSI values. Six elite genotypes viz., G11, G3, G9, G2 (PMMS-1), G5 and G17 yielded 73.0 to 134.0% higher than standard check i.e. 'Pusa Chetki' (93.8 q/ha) and are recommended for further evaluation at multi -locations before being considered for commercial release.