Evaluation of Khorasan Razavi’s Wheat Landraces (Triticum aestivum) Under Drought Stress and Identification of Effective Traits on Grain Yield

Abstract

Bread wheat (Triticum aestivum L) is one of the most important crops that is grown in most parts of the world in different climatic conditions. But biotic and abiotic stresses reduce the yield of this crop. Among abiotic stresses, drought stress is one of the most important factors in reducing yield in most cultivated areas of this crop. Resistant cultivar is one of the basic strategies to overcome the problems caused by drought stress. This experiment was carried out in order to identify and determine the most tolerant of native bread wheat genotypes of Khorasan Razavi province of Iran country in drought stress, in the research farm of the Department of Agronomy and Plant Breeding of the Campus of Agriculture and Natural Resources, University of Tehran in 1400-1399. In this experiment, 105 native populations with 4 controls in two environments: normal and drought stress were studied using augmented design. The traits evaluated included phenological, morphological, yield and yield components. The results showed that drought stress reduced most traits, including yield (21.87%), biological yield (24.39%), and thousand-seed weigh (8.64%). Phenotypic correlation, regression and path analysis, showed that grain filling period, biological yield, harvest index, thousand grain weight, number of grain per spike, grain weight per spike increased grain yield under drought stress. Stem weight had a negative relationship with grain yield. Cluster analysis was performed according to the ward method. The genotypes were divided into 8 groups in the normal environment and seven groups in the stress environment. The first and third groups of stress environment were introduced as tolerant and more tolerant groups respectively.