Bacterial blight(BB),which is caused by Xanthomonas oryzae pv.oryzae(Xoo),is an important rice disease responsible for significant yield losses.In the rice-growing regions of South China where BB outbreaks are common,the resistance of cultivars with BB resistance genes Xa4 and Xa21 has been lost because of rapid changes in the Xoo population structure and virulence.In this study,421 diverse rice accessions were evaluated regarding their resistance to two Xoo strains,namely GD1358(C5)and IV,which are prevalent pathotypes in South China and overcame the resistance of Xa4 and Xa21,respectively.Using the 4.8mio filtered SNP dataset,we conducted a genome-wide association study,which identified 13 loci associated with BB resistance,including eight new quantitative trait loci(QTL)and five QTL harboring known BB resistance genes:Xa3/Xa26,xa5,Xa35(t),Xa36(t),Xa40,Xa43(t),and xa44(t).Intriguingly,a steep peak was detected on chromosomes 5 and 11.Six QTL including three new ones,were distributed on chromo-some 11,whereas a new QTL qBB5.1 and a known QTL were detected on chromosome 5.Haplotype anal-yses indicated that the LOC_Os05g01610(OsPRAF2)gene within the qBB5.1 region,which encodes a PRAF protein,is associated with BB resistance.Furthermore,OsPRAF2 knockout lines generated using the CRISPR-Cpf1 system were significantly more resistant to Xoo strains than the wild-type plants.Our results provide researchers and breeders with useful information regarding QTL and gene resources,which may be relevant for developing new BB-resistant rice cultivars.

Jialing Lu;Quanlin Li;Chunchao Wang;Mingming Wang;Dan Zeng;Fan Zhang;Wenxue Zhai;Yongli Zhou

National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing 100101,China

作物学报（英文版）

[1]Jialing Lu;Quanlin Li;Chunchao Wang;Mingming Wang;Dan Zeng;Fan Zhang;Wenxue Zhai;Yongli Zhou-.Identification of quantitative trait loci associated with resistance to Xanthomonas oryzae pv.oryzae pathotypes prevalent in South China)[J].作物学报（英文版）,2022(02):498-507

pathotypes,GD1358,8mio,Xa3,Xa26,Xa35,Xa36,Xa40,Xa43,xa44,qBB5,Os05g01610,OsPRAF2,PRAF

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