Virulence Diversity of Colletothrichum lindemuthianum in Guatemala and GWAS to identify genomic regions associated with anthracnose resistance in common bean

Authors: MALDONADO-MOTA, C - North Dakota State University; Pastor Corrales, Marcial; Hurtado-Gonzales, Oscar; MOGHADDAM, S - Michigan State University; SCHRODER, S - North Dakota State University; MCCLEAN, P - North Dakota State University; PASCHE, J - North Dakota State University; LAMPPA, R - North Dakota State University; TOBAR-PINON, M - North Dakota State University; VILLATORO-MERIDA, J - Institute Of Agricultural Science And Technology (ICTA); MIRANDA, A - Institute Of Agricultural Science And Technology (ICTA); MOSCOSO, J - Institute Of Agricultural Science And Technology (ICTA); AGREDA, K - Institute Of Agricultural Science And Technology (ICTA); OSORNO, J - North Dakota State University

Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Trade Journal
Publication Acceptance Date: 2/19/2018
Publication Date: 4/30/2018
Citation: Maldonado-Mota, C.R., Pastor Corrales, M.A., Hurtado-Gonzales, O.P., Moghaddam, S.M., Schroder, S., Mcclean, P.E., Pasche, J., Lamppa, R., Tobar-Pinon, M.G., Villatoro-Merida, J.C., Miranda, A.N., Moscoso, J.R., Agreda, K., Osorno, J.M. 3018. Virulence Diversity of Colletothrichum lindemuthianum in Guatemala and GWAS to identify genomic regions associated with anthracnose resistance in common bean. Bean Improvement Cooperative Annual Report. 61:9-10.

Interpretive Summary: Climbing bean, a main source of protein for the people in the highlands of Guatemala, is imperiled by the pathogen that causes anthracnose disease. This pathogen is known to have many virulent populations known as races. Common bean varieties with resistance genes can control specific races of this disease. One of the objectives of this study was to identify the races that prevail in the highlands of Guatemala. This was conducted using a standard group of differential bean cultivars used to identify races of the anthracnose pathogen. In addition, a collection of 369 climbing beans from Guatemala were inoculated with a race of the anthracnose pathogen that occurs in many countries, including the United States. Moreover, a genome wide association study (GWAS) was conducted on the 369 climbing beans with the objective of finding DNA regions containing anthracnose resistance. These studies revealed six different races of the anthracnose pathogen in Guatemala that, as expected, infect Guatemalan beans. About 10% of the 369 climbing beans from Guatemala were resistant to race 73, indicating that there are anthracnose resistance sources among the Guatemalan beans. The GWAS study revealed that anthracnose resistance was present on two bean chromosomes (Pv04 and Pv07), which are known to contain genes conferring anthracnose resistance. These results will be useful for the development of climbing beans with anthracnose resistance.

Technical Abstract: Anthracnose is a major disease affecting common bean production worldwide. This disease threatens climbing bean production in Guatemala. Climbing beans are the main source of protein for the people of this region. Thus, resistant bean cultivars are needed to control this disease. Due to the extensive virulence diversity of the anthracnose pathogen, it is important to identify sources of resistance to the strains of the pathogen in the highlands of Guatemala. The virulence diversity of this pathogen in Guatemala was studied using a standard international set of 12 differential cultivars. Six races were identified among the samples collected from the Highlands. Most of these races, as expected, appeared be Mesoamerican, that infect preferentially infect common beans of Mexican and Central American origin. The germplasm collection from ICTA Guatemala was evaluated for their reaction to race 73, a race that is prevalent in the United States and many other countries. Approximately 10% of 369 climbing bean accessions showed no anthracnose symptoms, suggesting that these accessions have genes conferring resistance to the anthracnose pathogen. In addition, a genome wide association study (GWAS), using 78754 single nucleotide polymorphism (SNPs) markers, was conducted on the 369 climbing beans from Guatemala. This study revealed that that there were genomic regions for resistance to the anthracnose pathogen on chromosomes Pv04 and Pv07, which are known to contain several anthracnose resistance genes of Mesoamerican origin. The results of these studies will contribute to the development of anthracnose resistant cultivars for the highlands of Guatemala.