Inheritance Analysis Of Rust Resistance Genes And Its Related Genes Mining In Wheat Germplasm Y1499

Wheat stripe rust is an important disease that threatens the safety of wheat production worldwide.It can be controlled by chemical agent,appropriate cultivation practices,breeding and planting disease-resistant varieties,etc.Notably breeding disease-resistant varieties is the most economical and effective way to control the disease.However,the genetic diversity of wheat cultivars is narrow.Therefore,the utilization of alien genes from wheat relatives to increase genetic diversity is necessary for improving wheat yield and resistance in modern wheat breeding.Triticum turgidum subsp.durum（T.turgidum,2n=28,AABB）,a subspecies of Triticum turgidum L.,contains a large number of excellent genes that can be used to improve wheat quality and is an important source of genes resistance to stripe rust.Y1499 is a Tetraploid material of durum wheat,which showed high resistance at seedling stage and high resistance at adult stage for stripe rust race CYR32 and CYR34,respectively.In order to analyze the genetic characteristics of the disease resistance gene in durum wheat germplasm Y1499 and exploit new stripe rust resistance gene/loci,this study constructed a genetic population through crossing Y1499 with susceptible material Gaza.The genetic model of stripe rust resistance gene in Y1499 was analyzed by the method of"main gene plus polygenic genetic model",while gene mapping and prediction of stripe rust resistance related genes were carried out by using the BSR-seq strategy.The main results are as follows:（1）The main gene plus multigene mixed genetic model was adopted to estimate the genetic model combining P₁,P₂,F₁ and F₂ four populations.And then,it was found that the resistance of Y1499 to race CYR32 was determined by two pairs of equal additive main genes,and the inheritance rate of main gene was 96.23%.（2）RNA bulked transcriptome sequencing was performed by constructing bulked pools for extreme traits in two F_3:4 populations.And ED⁴ and K algorithms were used to locate disease resistance genes,three prediction intervals were detected in this study,i.e.QTLyr3A in the region of 677.65 Mbp-710.62 Mbp,QTLyr1A ranging 1.17Mbp-1.22 Mbp and QTLyr3B in 666.07 Mbp-703.94 Mbp.Comparing analysis with the previously officially named genes derived from durum wheat,the result indicates that the germplasm Y1499 carries two genes/loci for resistance to stripe rust,which are likely to be a new gene.（3）Furthermore,transcriptome data was employed to analyze differentially expressed genes,and found that the differentially expressed genes between resistance bulk and susceptible bulk constructed from the segregated plants in F_3:4HIF population were significantly enriched in GO term:response to oxidative stress and response to stress.In which,a total of 16 genes were found.Further KEGG pathway enrichment analysis of differential genes found that the metabolic pathways related to plant disease resistance,glutathione metabolism,phenylpropane biosynthesis and ABC transporter metabolism pathway were significantly enriched,and a total of 10 genes were overlapped in the plant-pathogen interaction metabolic pathway of the two groups.These genes were very likely to be closely implicated into the resistance network triggered by main gene and participated in the immune response of germplasm Y1499 to stripe rust.In addition,the differentially expressed genes were analyzed in the localization intervals and 13 differentially expressed genes were identified,which respectively encoded NBS-LRR proteins,laccase（LAC）,receptor-like proteins（RLPs）and other plant immune-related proteins reported by multiple studies,which are most likely candidate genes for the main gene of germplasm Y1499 resistance to stripe rust.This study provides a theoretical foundation for the analysis of material Y1499 stripe rust resistance loci and its potential use in molecular breeding of wheat stripe rust resistance.