Gene Mapping Of Powdery Mildew Resistance In Wild Emmer Wheat Based On Whole Genome Resequencing And BSR-seq

Wild emmer wheat（Triticum dicoccoides,2n=4x=28,AABB）originated from the Middle East of Israel,Turkey and other countries.It is a donor of hexaploid wheat A and B genomes.Besides,it is an important resource for wheat disease resistance and reverse genetic improvement.In the early days,the“Evolution Canyon”of Mount Carmel,Israel,proved to be a natural laboratory for studying biological antibiotics and abiotic stresses.In this study,35materials from the“Evolution Canyon”were identified for the resistance spectrum of powdery mildew.It was discovered that the wild Emmer wheat population of the southern slope of the“Evolution Canyon”（north-facing slope）evolved powdery mildew resistance and produced resistance to spectral diversity.Implying that it has evolved multiple disease resistance genes.The research team has initially mapped Ml ES4,which belongs to the first class of anti-spectrum,to the end of the long arm of chromosome 4A.On this basis,the subject further encrypts its genetic map and locates it within 0.5 c M genetic distance.In addition,in order to carry out genetic analysis on another type of wild-type germplasm resistant to spectrum.In this subject,the F₂ mapping population and the recombinant inbred line population（RIL）F₆ were constructed using ES14 and the canary powdery mildew material AS14 of the canyon,and the preliminary gene mapping and transfer utilization were carried out by using BSR-seq and other techniques.The specific research results are as follows:1.Identification of resistance to powdery mildew in“Evolutionary Canyon”.This study used six physiological races of powdery mildew E09,21-2-8,46-30,E21,E05 and mixed races.Identification of resistance to powdery mildew in 35 wild Emmer wheat derived from“Evolution Canyon”.The results of disease resistance identification showed that the materials on the South-facing slope of the canyon were all susceptible,while the material on the North-facing slope of the canyon were all resistant to disease.However,there are differences in resistance between different materials on the North-facing slope of the canyon.Among them,ES6,ES5,ES4,and ES2 belong to one category,and ES3、ES1、ES9、ES10、ES17、ES7、ES11、ES14、ES15、ES8、ES12、ES20 belong to another category.The results prove that the canyon microenvironment not only causes the difference of resistance to powdery mildew on the north and south slopes,but the southern slope germplasm has evolved the resistance to powdery mildew resistance,suggesting the evolution of different resistance genes.2.Encryption of the Ml ES4 genetic map of the resistance to powdery mildew genes:In this study,a single isolate group constructed by self-crossing of individual plants in the ES4/AS15F₃population with selected target gene regions was constructed.Combining ES4and AS15 whole-genome transcriptome sequencing data,the Ml ES4 gene was mapped between the markers XWsadu73134 and XWsadu73136 with a genetic distance of 0.5c M.3.The initial location of ES14 resistance to powdery mildew genes:In this study,F₂mapping population and recombinant inbred line population（RIL）F₆ were constructed using the wild emmer wheat ES14 with powdery mildew resistance on the North-facing slope of the canyon and AS14 with susceptible the South-facing slope of the canyon.BSR-seq analysis of their parents and anti-sensitive pools.The results indicated that the resistance gene may be located on chromosome 5A and 7A.Therefore,we speculate that the ES14 resistance to powdery mildew genes is not a quality trait controlled by a single gene,but a result of multiple QTL genes acting together.4.Transfer of genes resistant to powdery mildew:In this study,the resistance to powdery mildew gene was transferred by using the resistant wild emmer wheat ES14 and common wheat cultivars（lines）ES14.Currently,SN3050 and wild emmer wheat with powdery mildew have been obtained.The hybrid progeny of ES14 was BC₂F₁,and the BC₂F₁progeny plants showed resistance to field powdery mildew in the seedling stage.The parental SN3050 resistance grade was grade 4 and the offspring showed grade 1-2.In addition,the new wheat lines SN25053 and SN610361,which are susceptible to powdery mildew,were used as the female parent,and hybrid F₁ was obtained by crossing with the resistance to powdery mildew wild emmer wheat ES14.