Plant Genetic Group, Area of Horticultural and Forest Crops, SERIDA, Villaviciosa Asturias, Spain.
PLoS One. 2019 Feb 14;14(2):e0212298. doi: 10.1371/journal.pone.0212298. eCollection 2019.
A complex landscape of anthracnose resistance genes (Co-) located at the telomeric regions of the bean chromosomes Pv01 and Pv04 has been reported. The aim of this work was to investigate the genetic and physical positions of genes conferring resistance to races 6, 38, 39, 357, 65, and 73 as well as the relationships among the resistance genes identified herein and the previously described Co- genes in these telomeric regions. The linkage analysis using a genetic map of 497 SNPs from the recombinant inbred line population Xana/BAT93 revealed that the gene conferring resistance to race 65 in cultivar Xana (Co-165-X) was located in the Co-1 cluster, at the distal end of chromosome Pv01. The fine mapping of Co-165-X indicated that it was positioned between the physical positions 49,512,545 and 49,658,821 bp. This delimited physical position agrees with the positions of the previously mapped genes Co- 14, Co-x, Co-14, Co-1HY, and Co-Pa. Responses to races 6, 38, 39, and 357 in BAT93 exhibited co-segregation suggesting that the same gene, or very closely linked genes, were involved in the control. The linkage analysis showed that the resistance gene to race 38 in the genotype BAT93 (Co-338-B) was located at the beginning of chromosome Pv04, in the genetic position of the Co-3 cluster, and was flanked by markers with physical positions between 1,286,490 and 2,047,754 bp. Thus, the genes Co-3, Co-9, Co-10, Co-16, and Co-338-B, found in this work, form part of the same anthracnose resistance cluster at the beginning of chromosome Pv04, which is consistent with the discontinuous distribution of typical R genes annotated in the underlying genomic region. Resistance loci involved in the response to race 73 in the genotypes Xana (R) and BAT93 (R) were mapped to the same positions on clusters Co-1 and Co-3, respectively. The positioning of the resistance genes in the bean genome based on fine linkage mapping should play an important role in the characterization and differentiation of the anthracnose resistance genes. The assignment of Co- genes to clusters of race specific genes can help simplify the current scenario of anthracnose resistance.
已报道位于菜豆染色体 Pv01 和 Pv04 端粒区域的炭疽病抗性基因（Co-）的复杂图谱。本工作的目的是研究赋予对 6 号、38 号、39 号、357 号、65 号和 73 号菌株抗性的基因的遗传和物理位置，以及鉴定的这些基因与先前在这些端粒区域中描述的 Co-基因之间的关系。利用 Xana/BAT93 重组自交系群体的 497 个 SNP 的遗传图谱进行的连锁分析表明，在 Xana 品种中赋予对 65 号菌株抗性的基因（Co-165-X）位于 Pv01 染色体的远端 Co-1 簇内。Co-165-X 的精细定位表明，它位于物理位置 49,512,545 和 49,658,821 bp 之间。该限定的物理位置与先前映射的基因 Co-14、Co-x、Co-14、Co-1HY 和 Co-Pa 的位置一致。BAT93 对 6 号、38 号、39 号和 357 号菌株的反应表现出共分离，表明同一基因或非常紧密连锁的基因参与了控制。连锁分析表明，基因型 BAT93 中对 38 号菌株的抗性基因（Co-338-B）位于 Pv04 染色体的起始处，在 Co-3 簇的遗传位置，并且由物理位置在 1,286,490 和 2,047,754 bp 之间的标记所包围。因此，本工作中发现的 Co-3、Co-9、Co-10、Co-16 和 Co-338-B 基因构成了 Pv04 染色体起始处同一炭疽病抗性簇的一部分，这与在基础基因组区域注释的典型 R 基因的不连续分布一致。基因型 Xana（R）和 BAT93（R）中涉及对 73 号菌株反应的抗性基因座被定位到 Co-1 和 Co-3 簇上的相同位置。基于精细连锁作图的菜豆基因组中抗性基因的定位应在炭疽病抗性基因的表征和分化中发挥重要作用。将 Co-基因分配给特定菌株的基因簇有助于简化炭疽病抗性的当前情况。
