Evaluation of rain-fed wheat (Triticum aestivum L.) genotypes for drought tolerance

Document Type: Research paper

Authors

1 Department of Agronomy and Plant Breeding, College of Agriculture and Natural Resources, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran.

2 Department of Cereals, Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization, Maragheh, Iran.

3 Department of Agronomy and Plant Breeding, College of Agriculture and Natural Resources, Tehran University, Karaj, Iran.

4 Department of Cereals, Miandoab Agricultural Research Station, Miandoab, Iran.

10.30479/ijgpb.2020.12734.1265

Abstract

Drought stress is one of the most important environmental stresses that have limited the production of wheat, especially in arid and semi-arid regions of the world. To recognize drought tolerant rain-fed wheat genotypes and to determine the best tolerance/susceptibility indices, a study was conducted at the Agricultural Research Station of Miandoab for two cropping years (2013-15). The experimental materials included 12 rain-fed wheat genotypes investigated in two separate field experiments based on randomized complete blocks design with three replications under both rain-fed and supplemental irrigation conditions. The combined ANOVA for grain yield and agro-physiological traits showed that there was a large genetic difference between wheat genotypes for grain yield and studied traits in response to drought stress among years and moisture regimes. The different drought tolerance/susceptibility indices were used to characterize drought tolerance of genotypes. Generally, a reduction of RWC in drought tolerant genotypes (genotypes 6, 2, 11, and 10) was lower compared to the sensitive genotypes (genotypes 4 and 8). Cluster analysis based on drought tolerance indices categorized genotypes into two main groups. The genotypes belonging to the cluster 1 could be introduced as tolerant to the drought conditions. According to MSI (Multiple scoring index), genotypes 10 (Seafallah/3/Sbn//Trm/K253) and Saein had the best combination of productivity and resistance to drought stress. The significant correlation between MSI with grain yield under drought conditions indicated the superiority of MSI as a useful tool for efficient selection of drought-tolerant genotypes. In the present study there was no significant correlation between RWC and RWL with MP, GMP, STI and MSI indices under both conditions.

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