Genetic analysis of the response to eleven Colletotrichum lindemuthianum races in a RIL population of common bean (Phaseolus vulgaris L.)

Abstract

BackgroundBean anthracnose is caused by the fungus Colletotrichum lindemuthianum (Sacc. & Magnus) Lams.- Scrib. Resistance to C. lindemuthianum in common bean (Phaseolus vulgaris L.) generally follows a qualitative mode of inheritance. The pathogen shows extensive pathogenic variation and up to 20 anthracnose resistance loci (named Co-), conferring resistance to specific races, have been described. Anthracnose resistance has generally been investigated by analyzing a limited number of isolates or races in segregating populations. In this work, we analyzed the response against eleven C. lindemuthianum races in a recombinant inbred line (RIL) common bean population derived from the cross Xana × Cornell 49242 in which a saturated linkage map was previously developed.ResultsA systematic genetic analysis was carried out to dissect the complex resistance segregations observed, which included contingency analyses, subpopulations and genetic mapping. Twenty two resistance genes were identified, some with a complementary mode of action. The Cornell 49242 genotype carries a complex cluster of resistance genes at the end of linkage group (LG) Pv11 corresponding to the previously described anthracnose resistance cluster Co-2. In this position, specific resistance genes to races 3, 6, 7, 19, 38, 39, 65, 357, 449 and 453 were identified, with one of them showing a complementary mode of action. In addition, Cornell 49242 had an independent gene on LG Pv09 showing a complementary mode of action for resistance to race 453. Resistance genes in genotype Xana were located on three regions involving LGs Pv01, Pv02 and Pv04. All resistance genes identified in Xana showed a complementary mode of action, except for two controlling resistance to races 65 and 73 located on LG Pv01, in the position of the previously described anthracnose resistance cluster Co-1.ConclusionsResults shown herein reveal a complex and specific interaction between bean and fungus genotypes leading to anthracnose resistance. Organization of specific resistance genes in clusters including resistance genes with different modes of action (dominant and complementary genes) was also confirmed. Finally, new locations for anthracnose resistance genes were identified in LG Pv09.

<b>Classification of <i>Colletotrichum lindemuthianum</i> races in differential cultivars of common bean

“…Isolates 14835 and 14834 were pathogenic to six; isolates 14789, 14788, 14652, and 14782 were pathogenic to five; and the other isolates, 14779, 14783, 14781, 14784, 1467, and 14780, were pathogenic in four cultivars or fewer (Figure 1). The interaction between P. vulgaris and C. lindemuthianum was studied by Campa, Rodríguez-Suárez, Giraldez, and Ferreira (2014), and the authors reported that this interaction is specific and complex, conditioned by the pathogenic variation and by the genotype. They identified by mapping the RIL's population 'Cornell49242 x Xana' two resistance genes for race 65, which exhibited a dominance action mode unlike the other races, which exhibited different action modes in both parents and might be eventually addictive or dominant.…”

Mapping and Genetic Structure Analysis of the Anthracnose Resistance Locus Co-1HY in the Common Bean (Phaseolus vulgaris L.)

“…Currently, twenty-three related anthracnose resistance genes have been identified by the ‘ Co ’ symbol, including Co-1 to Co-7 , Co-8 , Co-9 to Co-15 , Co-17 , Co-u to Co-z , and CoPv09 [3–5]. Among these genes, Co-1 , Co-x and Co-w belong to the Andean gene pool, and the others belong to the Mesoamerican gene pool.…”

“…Additionally, Co-5 , Co-6 and Co-v were located on the Pv07 [18,19], Co-4 on the Pv08 linkage group and Co-2 on the Pv11 [16,20,21]. Recently, Campa et al identified a new gene CoPv09 on Pv09 [3]. …”

Transcriptome Profiling of the Phaseolus vulgaris - Colletotrichum lindemuthianum Pathosystem

“…Seventeen independent loci, Co-1 to Co-17 , conditioning resistance have been mapped to eight bean chromosomes (Pv01, Pv02, Pv03, Pv04, Pv07, Pv08, Pv09 and Pv11) [11, 21, 22, 23], and a graphic depiction of the mapped Co genes is displayed in Meziadi et al [24]. Anthracnose resistance is dominant at all loci except the Co-8 locus, and multiple alleles have been identified at the Co-1 , Co-3 , Co-4 , and Co-5 loci.…”