Fine Mapping Of The Major Locus QGLS1.02 From Qi319 Resistance To Gray Leaf Spot In Maize

Gray leaf spot?GLS?,which mainly caused by the causal fungal pathogen Cercospora zeae-maydis,is one of the most serious foliar diseases of maize worldwide.In the present study,based on a recombinant inbred lines?RILs?population harboring 300 lines,derived from a resistant inbred line Qi319 and a susceptible line Ye478,a genetic map containing 199 SSR markers were constructed to conduct a initial QTL mapping,and found a major locus on chromosome 1 named qGLS1.02 between SSR markers umc2614 and bnlgl803,long to 5.73Mb.Nineteen chromosome segment substitution lines?CSSLs?,with the genetic background of Ye478,were taken for the verification of the QTL.It was revealed that the lines containing the chromosome fragment,covering the initial QTL from Qi319,were more resistant to GLS than the lines without qGLS1.02?P<0.01?.Ten CSSLs recombinants and their derived progeny were used to conduct a fine mapping,and with a recombinant-derived progeny test strategy,the qGLS1.02 was narrowed into an interval of 363.61Kb according to the B73 RefGen_v2 genome.There are five genes within qGLS1.02 through the website Maize GDB,further,the five genes were analyzed with bioinformatics to predict candidate gene,in which,the gene KHB5 was the only one expressing highly in leaf and had consistent function,being the candidate gene.Meanwhile,the favorite allele of SYLY₈0 from Qi319 was significantly associated with the GLS resistance in the panel of 201 maize inbred lines?P<0.01?,indicating its availability in the marker-assisted selection?MAS?.These results may prove valuable information of the mechanisms and MAS for the resistance to GLS in maize breeding.