DROUGHT TOLERANCE IN WHEAT USING STRESS SELECTION INDICES
Authors: Waseem Ullah Shah, Muhammad Anas, Ateeq Ur Rahman, Khushal Khan, Atta Ul Wahab, Hira Ali, Muhammad Taimur, Mian Ahmad Raza, Hilal Ahmad and Muhammad Shaban Afridi
Waseem Ullah Shah: Department of Plant Breeding and Genetics, University of Agriculture, Peshawar, Pakistan.
Muhammad Anas: Department of Plant Breeding and Genetics, University of Agriculture, Peshawar, Pakistan & Ministry of Education Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China.
Ateeq Ur Rahman: Institute of Biotechnology and Genetic Engineering, The University of Agriculture, Peshawar.
Khushal Khan: Department of Plant Breeding and Genetics, University of Agriculture, Peshawar, Pakistan.
Atta Ul Wahab: Institute of Biotechnology and Genetic Engineering, The University of Agriculture, Peshawar.
Hira Ali: Department of Plant Breeding and Genetics, University of Agriculture, Peshawar, Pakistan.
Muhammad Taimur: Department of Plant Breeding and Genetics, University of Agriculture, Peshawar, Pakistan.
Mian Ahmad Raza: Department of Plant Breeding and Genetics, The University of Agriculture, Swat.
Hilal Ahmad: Institute of Biotechnology and Genetic Engineering, The University of Agriculture, Peshawar.
Muhammad Shaban Afridi: Institute of Biotechnology and Genetic Engineering, The University of Agriculture, Peshawar.
ABSTRACT
Drought is one of the most limiting abiotic stresses affecting wheat crops. It is a significant abiotic factor affecting the yield and yield stability of cereal crops, and it simultaneously affects many traits leading to yield reduction. The current research was conducted at the University of Agriculture, Peshawar, during 2021-2022. Twenty wheat genotypes, including two checks, Khaista and Wadan, were evaluated in RCBD under irrigated and rainfed environments for genetic variability, drought tolerance indices, and broad-sense heritability of various traits. Analysis of variance revealed highly significant variation among genotypes for spike length, biological yield, grain yield, and harvest index, while significant variations were observed for spikes m-2, spikelets spike-1, and 1000-grain weight. Significant genotype × environment interaction was observed for all the studied traits. Different tolerance indices, like MP (mean productivity), GMP (geometric mean productivity), TOL (tolerance), SSI (stress susceptibility index), YI (yield index), YSI (yield stability index), and RDI (relative drought index) were estimated based on yield in irrigated and rainfed conditions. Under an irrigated environment, the highest yield was recorded for G-163 (5700.0 kg ha-1) and G-155 (5570.8 kg ha-1), while under a rainfed environment, Wadan (5161.1 kg ha-1) and G-163 (4852.8 kg ha-1) were the highest yielding genotypes. Under an irrigated environment, heritability was high for biological yield (0.71) and harvest index (0.77). Under a rainfed environment, heritability was high for grain yield (0.69) and harvest index (0.77), while low heritability was observed for spikelets spike-1 (0.22). GMP and MP had a positive, highly significant correlation with all the productive traits under both environments, thus it will be more useful for trait selection under rainfed and irrigated environments. YI was positive and highly significantly correlated with all yield contributing traits in rainfed conditions, thus YI would be a more reliable selection index in a rainfed environment. Wheat genotype G-163 showed the best performance under both tested conditions and can be recommended to be tested in further breeding programs for yield improvement.
Keywords: Wheat; G × E interaction; Tolerance indices; Heritability; Mean productivity; Geometric mean productivity.