Qiaoyun Li;Runyu Hu;Zhenfeng Guo;Siyu Wang;Chuang Gao;Yumei Jiang;Jianwei Tang;Yin Gu

National Engineering Research Centre for Wheat, College of Agronomy, National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou 450002, Henan, Chin;National Engineering Research Centre for Wheat, College of Agronomy, National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou 450002, Henan, China

Black point;Molecular marker;Quantitative trait locus;Triticum aestivu

Black point disease caused by Bipolaris sorokiniana is a problem in wheat production worldwide. We aimed to identify major quantitative trait loci (QTL) for resistance to black point and develop molecular markers for marker-assisted selection (MAS). A recombinant inbred line (RIL) population derived from a cross between Wanyuanbai 1 (susceptible) and SN4143 (resistant) was evaluated for black point response at three locations during two years under artificial inoculation with B. sorokiniana, providing data for six environments. Thirty resistant and 30 susceptible RILs were selected to form resistant and susceptible bulks, respectively, that were genotyped by the wheat 660K SNP array; 685 single-nucleotide polymorphisms (SNPs) were identified, among which 385 (56.2%) and 115 (16.8%) were located on chromosomes 4A and 2B, respectively. Bulked segregant RNA-Seq analysis identified candidate regions on chromosomes 4A (4.60-40.28 Mb) and 5A (1.22-48.47 Mb). Genetic linkage maps were con-structed for chromosomes 2B, 4A, and 5A using 59 polymorphic dCAPS and SSR markers. Finally, two QTL, designated QBB.hau-4A and QBB.hau-5A, were detected on chromosomes 4A and 5A, respectively. The resistance allele of QBB.hau-4A was derived from SN4143, and that of QBB.hau-5A came from Wanyuanbai 1. QBB.hau-4A with a large and consistent effect (15.1%) is likely to be a new locus for black point resistance. The markers linked to QBB.hau-4A and QBB.hau-5A have potential application in MAS-based breeding.(c) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).