PERFORMANCE AND STABILITY OF SOME EARLY MATURING BREAD WHEAT GENOTYPES UNDER DIFFERENT ENVIRONMENTS

doi:10.12816/ejpb.2019.256688

PERFORMANCE AND STABILITY OF SOME EARLY MATURING BREAD WHEAT GENOTYPES UNDER DIFFERENT ENVIRONMENTS

Document Type : Original research

10.12816/ejpb.2019.256688

Abstract

Four bread wheat promising early maturing lines and two local cultivars were evaluated in two locations, i.e. Sakha and Sids Agricultural Research Stations for the two successive seasons 2014/2015 and 2015/2016 under two sowing dates (recommended and late). The experimental design was randomized complete block design with four replicates in each experiment. The main objective of this study was to select the best genotypes and study the relationships among characters under recommended and late sowing dates. The combined analysis of variance showed significant or highly significant differences among environments and genotypes for all studied characters. The results revealed that the genotypes responded differently to sowing dates for grain yield, indicating the possibility of selecting the best genotypes under a specific environment. Line 2 and Line 1 had the highest grain yield under late sowing conditions (8.166 and 8.038 ton/hectare, respectively). The relationships between grain yield and each of days to heading and days to maturity were significant positive under the recommended sowing date, indicating that the genotypes which have long growth duration had the highest grain yield. On the contrary, these relationships were negative under late sowing date, indicating the advantages of earliness under late conditions. High heritability estimates were obtained for days to maturity indicating selection would be effective to improve this character. Moderate heritability was detected for days to heading, grain filling rate, plant height and grain yield, suggesting that delaying selection to advanced segregating generations is better. Expected genetic advance from selection as a percentage of the mean was high for grain yield and grain filling rate, and low for plant height, days to maturity, kernels per spike and 1000-kernel weight. According to stability analysis and GGE-biplot, Line 2 was the most stable genotype across all environments followed by Line 1 and Shandaweel 1.

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