Identification and DNA Marker Development for a Wheat-Leymus mollis 2Ns (2D) Disomic Chromosome Substitution.

Xianbo Feng,Yongfu Wang,Xin Du,Lihui Shang,Wanquan Ji,Pingchuan Deng,Chunhuan Chen,Jixin Zhao,Zengrong Tian,Changyou Wang,Siwen Wang

doi:10.3390/ijms23052676

Abstract

Leymus mollis (2n = 4x = 28, NsNsXmXm), a wild relative of common wheat (Triticum aestivum L.), carries numerous loci which could potentially be used in wheat improvement. In this study, line 17DM48 was isolated from the progeny of a wheat and L. mollis hybrid. This line has 42 chromosomes forming 21 bivalents at meiotic metaphase I. Genomic in situ hybridization (GISH) demonstrated the presence of a pair chromosomes from the Ns genome of L. mollis. This pair substituted for wheat chromosome 2D, as shown by fluorescence in situ hybridization (FISH), DNA marker analysis, and hybridization to wheat 55K SNP array. Therefore, 17DM48 is a wheat-L. mollis 2Ns (2D) disomic substitution line. It shows longer spike and a high level of stripe rust resistance. Using specific-locus amplified fragment sequencing (SLAF-seq), 13 DNA markers were developed to identify and trace chromosome 2Ns of L. mollis in wheat background. This line provides a potential bridge germplasm for genetic improvement of wheat stripe rust resistance.

Highlights

Common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is one of the major food crops in the world
When wheat is susceptible to Puccinia striiformis f. sp. tritici (Pst) infection, the yield loss is about 10–20%, but it can reach 50% or even result in no harvest in a pandemic year [1]
No trivalents or quadrivalents were observed at metaphase I, and no chromosomes were lagged at anaphase I (Figure 1c)

Summary

Introduction

Common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is one of the major food crops in the world. Against the background of the prominent contradiction between population growth and the shortage of resources, wheat yield is increasingly challenged. Wheat stripe rust, caused by the fungus Puccinia striiformis f. Tritici (Pst), is a serious threat to wheat production. When wheat is susceptible to Pst infection, the yield loss is about 10–20%, but it can reach 50% or even result in no harvest in a pandemic year [1]. The most economical, effective and environmental-friendly method is to breed resistant cultivars, but the narrow genetic basis of wheat restricts its genetic improvement [2]. It is necessary to provide new wheat germplasms with stripe rust resistance to facilitate wheat resistance breeding

Methods

Results

Discussion

Conclusion