Document Type : Research Paper - Biotic and Abiotic Stress
Authors
1 Fars Agricultural and Natural Resources Research and Education Center
2 Department of Plant Production and Genetics engineering, Faculty of Agricultural and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
3 Department of Plant Production and Genetics engineering, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
4 Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
Abstract
Introduction
Barley is one of the important crops in the cereal family and has a wide range of adaptation to various environmental conditions and abiotic stresses, particularly drought, salinity, and cold. Crop plants are often exposed to environmental stresses. Since barley cultivars in semi-arid regions face drought stress in their growth stages, and considering the importance of identifying the best cultivars for these areas, this research aims to investigate barley cultivars in terms of morphological and phenological characteristics, as well as to identify traits related to grain yield in order to select the best cultivars.
Materials and methods
In this experiment, 17 promising barley genotypes along with four control genotypes were tested under two conditions: non-stress irrigation and terminal drought stress, during crop years 2022-2024. This tool place in a randomized complete block design with three replications at the Darab Agricultural and Natural Resources Research Station. The multi-trait genotype-ideotype distance index (MGIDI) and multi-trait stability index (MTSI) were utilized to select superior genotypes based on grain yield and other measured traits. The measured traits included of number of days to heading (DHE), number of days to maturity (DMA), plant height (PLH), grain filling period (GFP), grain filling rate (GFR), thousand grain weight (TGW), grain yield (YLD), number of grains per spike (NGS), spike harvest index (SHI), spike fertility index (SFIm), and spike weight (SPW).
Results and Discussion
The combined analysis of variance for the studied traits indicated that the effects of environment, genotype, and genotype × environment were significant for all the examined traits. The environment was the primary source of variation for the traits DHE, DMA, GFR, TKW, and YLD, whereas genotypic effects were the main source of variation for the traits PLH, GFP, NGS, SFLm, and SPW. Results from factor analysis in each environment and across all environments revealed a strong relationship between YLD and traits such as GFP, GFR, SHI and SFLm. Indirect selection through these traits under both non-stress and drought stress conditions may enhance grain yield in barley genotypes. Based on the MGIDI index under non-stress conditions (2021-2023), genotypes G16, G2, G20, and G1 outperformed the others, while genotypes G16, G18, G10, and G14 were identified as ideal genotypes under drought stress conditions (2021-2023). According to the MSTI index across all environments, genotypes G5, G8, and G3 were among the most stable for various studied traits. Under non-stress conditions, the selection differential was positive for all traits except DHE, with the highest selection differential values were observed for traits YLD (12.6), SFLm (8.64), and GFP (8.19). This indicates the MGIDI method’s effectiveness in selecting high-yielding genotypes with desirable agronomic traits. Conversely, under drought stress conditions, the selection differential was negative for traits DHE, DMA, and PLH, while the highest selection differential values were for traits SFLm (13.90), YLD (10.7), and GFR (9.35). This suggests the method effectively select early-maturing genotypes with high grain yield, grain filling rate, and spike fertility index under drought stress conditions. Across all studied environments and under both non-stress and drought stress conditions throughout the two years, the highest gain was observed for traits such as grain yield, grain filling rate, and spike fertility index. This indicates the identification of genotypes with high grain yield potential, high grain filling rate, and increased spike fertility index.
Conclusion
Overall, results indicated that the selected genotypes under non-stress conditions (G16, G2, G20, and G1) exhibited a combination of traits such as long grain filling period, high grain filling rate, high grain yield, maximum number of grains per spike, high spike fertility index, and ultimately high spike weight. On the other hand, selected genotypes under drought stress conditions (G16, G8, G10, and G14) displayed traits such as long grain filling period, high grain yield, and high spike fertility index. Therefore, each of these genotypes could be a potential candidate for introduction under both non-stress and late-season drought stress conditions. Since genotype G16 was selected under both conditions, it can be introduced as the top genotype. Moreover, based on the MSTI index, genotype G3 was one of the most stable, displaying a grain yield higher than the overall average.
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