Selection of Superior Drought Tolerant Genotypes of Durum Wheat using Graphic Analysis Based Methods

Drought is the most important limiting factor for durum wheat production in the Mediterranean and other regions. Iran is located in arid and semi-arid parts of the word. In order to identify the most effective stress tolerance indices and the most tolerant durum wheat genotypes, this study was conducted as two separate experiments (one under normal irrigation conditions and the other cut off  irrigation after 50% spike) on 20 promising durum wheat lines in a randomized complete block design at three replications. The research was implemented at Neishabour Agricultural Research Station for two cropping seasons. Stress tolerance indices were calculated using the two-year average yield, which were MP, GMP, STI, SSI, TOL, YI, YSI, RDI, DI, MRP and REI. Biplot correlation equations could explain relation between grain yield and calculated indices where GMP, MP and STI were the best ones under both conditions. Lines 7 and 8 were identified as superior genotypes based on GGEBiplot polygon. Keeping in view both yield and stability adopting GGEBiplot, line 7 was favorable. Also Line 7 was ideal genotype in relevant biplot. Generally, results showed that GGEBiplot was suitable methods for identifying superior genotypes based on biplot indices considering both yield and stability.