AMMI and GGE biplot analysis of yield of different elite wheat lines under terminal heat stress and irrigated environment

Wheat crop in Nepal faces terminal heat stress which accelerates the gain filling rate and shortens the filling period which leads to reduced grain weight, size, number, quality that is yield loss. For minimization of this loss, genotypic selection of high yielding lines should be performed understanding the gene-environment interaction. With the view to obtain a high yielding line with stable performance across the environments an experiment was conducted using 18 elite wheat line and 2 check varieties in alpha lattice design (2 replication and 5 blocks per replication) in different environments viz. irrigated and terminal heat stressed environment. The analysis of variance revealed that genotype, environment and their interaction had highly significant effect on the yield. Furthermore, which-won-where model indicated specific adaptation of elite lines NL-1179, NL-1420, BL-4407, NL-1368 to irrigated environment and BL-4919 and NL-1350 to terminal heat-stressed environment. Similarly, Mean-versus-stability study indicated that elite line BL-4407, NL-1368, BL-4919, NL-1350 and NL-1420 had above average yield and higher stability whereas elite lines Gautam, NL-1412, NL-1376, NL-1387, NL-1404 and N-1381 had below average yield and lower stability. Also, ranking elite lines biplot, PCA1 explaining 73.6% and PCA2 explaining 26.4% of the interaction effect, showed the rank of elite line, NL-1420 > NL-1368> NL-1350 > other lines, close to ideal line. From these findings, NL-1420 with high yield and stability can be recommended across both the environment while NL-1179 is adapted specifically for irrigated and NL-1350 adapted specifically for terminal heat-stressed environment.