Introgression of Powdery Mildew Resistance Gene Pm56 on Rye Chromosome Arm 6RS Into Wheat.

Ming Hao,Lianquan Zhang,Jiangtao Luo,Zhongwei Yuan,Shunzong Ning,Chaolan Fan,Yingjin Yi,Dengcai Liu,Meng Liu,Youliang Zheng

doi:10.3389/fpls.2018.01040

Abstract

Powdery mildew, caused by the fungus Blumeria graminis f. sp. tritici, represents a yield constraint in many parts of the world. Here, the introduction of a resistance gene carried by the cereal rye cv. Qinling chromosome 6R was transferred into wheat in the form of spontaneous balanced translocation induced in plants doubly monosomic for chromosomes 6R and 6A. The translocation, along with other structural variants, was detected using in situ hybridization and genetic markers. The differential disease response of plants harboring various fragments of 6R indicated that a powdery mildew resistance gene(s) was present on both arms of rye chromosome 6R. Based on karyotyping, the short arm gene, designated Pm56, was mapped to the subtelomere region of the arm. The Robertsonian translocation 6AL⋅6RS can be exploited by wheat breeders as a novel resistance resource.

Highlights

Blumeria graminis f. sp. tritici (Bgt), the causative fungus of powdery mildew disease, can be a highly destructive pathogen of wheat
Of 10 D-2-3-4 × QL F1 hybrids, one produced three F2 progeny, and of these, only one was self-fertile. After selfing this individual through to the F11 generation with selection for good fertility, 42 lines were selected for karyotyping using Genomic in situ hybridization (GISH) and Fluorescence in situ hybridization (FISH)
The present experiments have established that wheat plants carrying chromosome 6R of cereal rye cv

Summary

Introduction

Blumeria graminis f. sp. tritici (Bgt), the causative fungus of powdery mildew disease, can be a highly destructive pathogen of wheat. Tritici (Bgt), the causative fungus of powdery mildew disease, can be a highly destructive pathogen of wheat. In which a wheat chromosome arm is fused to the opposite arm of a homoeologous chromosome present in a donor species belonging to the tertiary gene pool, represent a key intermediate in the process of alien introgression. Such so-called Robertsonian translocations are rather frequently induced during meiosis via the breakage-fusion of a pair of non-paired monosomes (Lukaszewski and Gustafson, 1983; Lukaszewski, 1997; Friebe et al, 2005). A 6AL·6VS translocation carrying Pm21 is present in some Chinese cultivars (Chen et al, 1995; Cao et al, 2011)

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Conclusion