Stress susceptibility and path- analysis of yield components of landrace genotypes of durum wheat from Khuzestan (Iran) in no-stress and stress environments

The influence of terminal environmental stress, high temperature and drought, on the developmental phases as well as on yield and its components were studied in the landrace genotypes of durum wheat (Triticum durum Desf.) under field conditions. The duration of all of the developmental stages, namely days from plant emergence to booting, to heading, to anthesis, and to maturity, along with number of grains per head, 1000 - grain weight, and harvest index was markedly reduced under stress environment. However, mean differences between the nonstress and stress environments were not significant for plant height, number of heads per plant, total dry matter, and straw yield. The most stress affected grain yield component was 1000 grain weight, indicating that under terminal stress, moisture and heat become the limiting factors at the time of grain filling