Genotype by Environment Interactions for Yield-Related Traits in Tunisian Barley (Hordeum vulgare L.) Accessions Under a Semiarid Climate

Marzougui Salem

doi:10.5586/aa.7344

Abstract

Genotype by environment interaction and stability analyses are among the most important evaluations conducted in plant breeding. In this study, we evaluated the yield-related traits of 32 Tunisian barley (<em>Hordeum vulgare </em>L.) accessions over three consecutive cropping seasons in a semi-arid environment. Phenotypic analysis identified heading date and spike length as the two major traits contributing most to the total phenotypic variation under a semiarid climate. Hierarchical clustering grouped the 32 accessions into four groups. Although the effect of the interaction between genotype and environment was important for yield (48%), it had comparatively little influence on heading date (9.9%) and plant height (8.14%). Stability analysis identified the djebali accession, with the smallest coefficient of variability, as a stable genotype across the three assessed environments. Overall, based on the higher yield and small coefficient of variance, we selected 11 promising genotypes. In addition, varieties developed by the Tunisian breeding program were found to show high mean yield, stability across all environments, and greater adaptability. Accessions with superior adaptation and stability will be introduced into the national breeding program for further evaluation and characterization.

Highlights

Barley (Hordeum vulgare L.) is one of the oldest cultivated crops worldwide, ranking fourth after wheat, rice, and maize
In Tunisia, barley is mainly cultivated in regions with arid and semiarid climates that receive less than 400 mm of rainfall annually, and as part of the Tunisian breeding program for barley, genetic studies are currently being conducted with the aim of enhancing yields
Yield in barley is a complex trait governed by several genes that interact with the environment, and the selection of genotypes based on performance in a single environment is an ineffective approach for varietal selection (Shrestha et al, 2012)

Summary

Introduction

Barley (Hordeum vulgare L.) is one of the oldest cultivated crops worldwide, ranking fourth after wheat, rice, and maize. Yield in barley is a complex trait governed by several genes that interact with the environment, and the selection of genotypes based on performance in a single environment is an ineffective approach for varietal selection (Shrestha et al, 2012). In this regard, the analysis of genotype by environment interactions is of particular importance, notably in regions of North Africa, wherein barley is often cultivated under adverse conditions of drought, high temperatures, and irregular rainfall (van Oosterom & Ceccarelli, 1993). The most widely adopted approaches in the study of genotype by environment interactions are based on models incorporating genotype main effects and Genotype × Environment interaction effects (Yan et al, 2000)

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Conclusion