GENOTYPE-ENVIRONMENT INTERACTIONS AND STABILITY ANALYSIS OF YIELD AND YIELD ATTRIBUTES OF TEN CONTEMPORARY WHEAT VARIETIES OF PAKISTAN

Abstract

Testing of wheat varieties in different agro-ecological zone is essential for evaluation of stability of performance and range of adaptations. The main objective of this study was to determine variety-environment interaction, stability and adaptability of various characters and effect of different environments relationship of characters with grain yield and grain protein percentage in spring wheat (Triticum aestivum L.) Ten varieties viz. Kiran-95, Mehran-89, Tandojam-83, Abadgar-93, Anmol-91, Punjab-96, Chakwal 86, Shahkar-87, Parwaz-94 and Pirsabak-85 were evaluated at nine different locations for three years during the 1999-2000, 2000-2001, and 2001-2002 respectively. Data were recorded on various plant characters viz. plant height, peduncle length, flag leaf area, productive tillers per meter, spike length, number of spikelets per spike, rachis segment length, number of grains per spike, 1000-grain weight, grain protein percentage, number of maturity days and grain yield (t/h). Variety-location (?vl) variety-year (?vy) and variety-location-year (?vly) interactions were highly significant for all characters. The relative magnitude of interaction variance components indicated that relative performance of varieties for plant height, peduncle length, flag leaf area, productive tillers parameter, rachis segment length, 1000-grain weight, grain protein percentage and grain yield were more inconsistent across locations than years. The opposite was true for spike length spikelets per spike, grain per spike and maturity days. The stability parameters (within variety mean square (Si²), variety coefficient of variation (CVi %), ecovalence (Wi²), variety interaction variance (?i²), regression coefficient (bi), deviation from regression mean square (?i²) and coefficient of determination (Ri²)), revealed a range of stability for all characters.