Identification of Candidate Genes and Genomic Regions Associated with Adult Plant Resistance to Stripe Rust in Spring Wheat

Amira M I Mourad,Mohamed A Abou-Zeid,P Stephen Baenziger,Shamseldeen Eltaher,Andreas Börner

doi:10.3390/agronomy11122585

Abstract

Wheat stripe rust (caused by Puccinia striiformis f. sp. tritici) is a major disease that damages wheat plants and affects wheat yield all over the world. In recent years, stripe rust became a major problem that affects wheat yield in Egypt. New races appeared and caused breakdowns in the resistant genotypes. To improve resistance in the Egyptian genotypes, new sources of resistance are urgently needed. In the recent research, a set of 95 wheat genotypes collected from 19 countries, including Egypt, were evaluated for their resistance against the Egyptian race(s) of stripe rust under field conditions in the two growing seasons 2018/2019 and 2019/2020. A high genetic variation was found among the tested genotypes. Single marker analysis was conducted using a subset of 71 genotypes and 424 diversity array technology (DArT) markers, well distributed across the genome. Out of the tested markers, 13 stable markers were identified that were significantly associated with resistance in both years (p-value ≤ 0.05). By using the sequence of the DArT markers, the chromosomal position of the significant DArT markers was detected, and nearby gene models were identified. Two markers on chromosomes 5A and 5B were found to be located within gene models functionally annotated with disease resistance in plants. These two markers could be used in marker-assisted selection for stripe rust resistance under Egyptian conditions. Two German genotypes were carrying the targeted allele of all the significant DArT markers associated with stripe rust resistance and could be used to improve resistance under Egyptian conditions.

Highlights

Wheat (Triticum aestivum L.) is one of the most important crops all over the world [1,2]
The objectives of this study were to (1) identify the genetic diversity of the Egyptian and other spring wheat genotypes in their resistance to the Egyptian race(s) of stripe rust, (2) understand the genetic control of the resistance against the Egyptian race(s) of stripe rust, (3) identify some diversity array technology (DArT) markers and genomic regions associated with stripe rust resistance to be used in marker-assisted selection for stripe rust resistance in wheat and (4) select the best resistant genotypes to be used in improving stripe rust resistance under Egyptian conditions in future breeding programs
In the remaining part of our manuscript, we focused only on the significant markers harboring high-confidence gene models

Summary

Introduction

Wheat (Triticum aestivum L.) is one of the most important crops all over the world [1,2]. During the life cycle of wheat, plants are attacked by different pathogens, including stripe rust Infection by stripe rust pathogens can occur at any time during the wheat growing season, from the one-leaf stage to maturity, resulting in a decreasing number of kernels/head and kernel mass/plant [6]. Fungicides are expensive, could be ineffective if not applied on time and harm the environment. On the other hand, planting resistant genotypes is a more effective, economical and easy method in controlling stripe rust disease [7,8]

Objectives

Results

Conclusion