Multi-Location Field Trials Revealed High-Yielding and Broad-Spectrum Resistance of Wheat (Triticum aestivum L.) to Leaf Rust (Puccinia triticina Eriks)

Abstract

Bread wheat plays a crucial role in global food and nutritional security and provides a dietary staple for more than 35% of the world population. In Ethiopia, the current national average wheat productivity of 3.33 t/ha is considerably lower than the global average due to the lack of improved varieties and leaf rust. This study aimed to identify high-yielding and durable leaf rust resistant genotypes for use in the subsequent wheat breeding programme. In this study, a total of 281 bread wheat genotypes were evaluated at three leaf rust hotspots namely Debre Zeit Agricultural Research Center (DARC), Chefe Sub station and Kulumsa Agricultural research Centers (KARC). The genotypes were evaluated for phonological traits, yield performance, and leaf rust resistance. Analysis of variance revealed highly significant differences (p ≤ 0.01) among genotypes, environments, and their interactions for agronomic and disease traits. The significant genotype by environment interaction indicates that the genotypes' performance for grain yield and leaf rust resistance differ across environments. The genotypes' yield performances at individual environments varied considerably, and the highest grain yield (12.5 t/ha) was observed at KARC. Grain yield exhibited a positive and statistically strong correlation with TKW and harvest index. Clustering based on grain yield performance grouped the wheat genotypes into five clusters. Principal Component Analysis revealed that the inclusion of the first two PCs can explain 99.7% of the total variations in grain yield performance of the genotypes. GGE biplot analysis identified that the wheat genotypes 111, 207, and 209 were high-yielding and more stable across the test sites. Among the tested wheat genotypes, 111, 46, 209, and 207 were the most resistant across all test environments. In this study, we identified new candidate genotypes with superior grain yield performance and stable leaf rust resistance for use as source material in wheat breeding programmes and contributed to increased and stable wheat production to ensure food and nutritional security in Ethiopia and beyond.