小麦山农4143抗黑胚病遗传分析及抗性遗传位点检测

 黑胚病是小麦生产的重要籽粒病害,麦根腐平脐蠕孢(Bipolaris sorokiniana)是黑胚病的主要致病菌。为分析小麦抗黑胚病遗传规律并检测抗性位点,本研究以抗黑胚病小麦品系山农4143与感病品系宛原白1号的F₇代重组自交系(RIL)群体为材料,于2018~2019年在3个试验点种植,采用“孢子液喷洒、套袋保湿”的方法进行接菌鉴定,用“主基因＋多基因混合遗传模型”进行遗传分析,并挑选极端抗、感自交系构建混池、结合小麦660K SNP芯片进行混合分组分析(BSA)。研究结果显示小麦品系山农4143对黑胚病抗性符合“4对主基因加性-上位性遗传模型”,主基因遗传力为0.88~0.95;通过BSA检测到黑胚病抗性位点36个,分别位于1A、2B(6)、2D(2)、3A、3B(2)、3D、4A(6)、4D、5A(4)、5B(6)、5D(3)、7A、7B和7D共14条染色体上,A、B、D染色组上分别为13、 15和8个,36个位点中有18个为抗黑胚病新鉴定位点。本研究结果为小麦抗黑胚病位点的精细定位和抗性育种中分子标记的开发奠定了基础。

Genetic analysis and detection of resistance loci for black point in wheat genotype Shannong4143

Black point disease, caused by the dominant pathogen Bipolaris sorokiniana, is a severe wheat grain disease. In order to analyze the genetic characters and detect the resistance loci for black point, the resistant genotype Shannong4143 and susceptible genotype Wanyuanbai1 and their recombinant inbred line (RIL) population at F₇ were planted at three experimental locations in 2018-2019 wheat growing season. Resistance identification was carried out using the method of spraying spore suspension of B. sorokiniana and bagging for moisture. The genetic analysis was carried out by mixed inheritance model of major genes plus polygenes. The extreme resistant and susceptible inbred lines were selected to build a mixed pool. Combining 660K SNP arrays, the resistant loci were detected by bulked segregate analysis (BSA). The results showed that: the resistance of wheat to black point caused by B. sorokiniana was in accordance with the "additive - epistatic inheritance model of 4 major genes", and heritability of the major gene was 0.88-0.95. Thirty-six loci were detected by BSA, which were located on 14 chromosomes of 1A, 2B (6), 2D (2), 3A, 3B (2), 3D, 4A (6), 4D, 5A (4), 5B (6), 5D (3), 7A, 7B and 7D, respectively. A total of 13, 15, and 8 loci were from the A, B, and D genomes, respectively. Among the 36 loci detected, 18 loci were new loci for resistance to black point. The results of this study laid a foundation for the fine mapping of resistance loci to black point and development of molecular markers in the breeding for resistant cultivars to black point.