A Review of Angular Leaf Spot Resistance in Common Bean

Abstract

Angular leaf spot (ALS), caused by Pseudocercospora griseola, is one of the most devastating diseases of common bean (Phaseolus vulgaris L.) in tropical and subtropical production areas. Breeding for ALS resistance is difficult due to the extensive virulence diversity of P. griseola and the recurrent appearance of new virulent races. Five major loci, Phg‐1 to Phg‐5, conferring ALS resistance have been named, and markers tightly linked to these loci have been reported. Quantitative trait loci (QTLs) have also been described, but the validation of some QTLs is still pending. The Phg‐1, Phg‐4, and Phg‐5 loci are from common bean cultivars of the Andean gene pool, whereas Phg‐2 and Phg‐3 are from beans of the Mesoamerican gene pool. The reference genome of common bean and high‐throughput sequencing technologies are enabling the development of molecular markers closely linked to the Phg loci, more accurate mapping of the resistance loci, and the comparison of their genomic positions. The objective of this report is to provide a comprehensive review of ALS resistance in common bean. Furthermore, we are reporting three case studies of ALS resistance breeding in Latin America and Africa. This review will serve as a reference for future resistance mapping studies and as a guide for the selection of resistance loci in breeding programs aiming to develop common bean cultivars with durable ALS resistance.

Genetic diversity of Pseudocercospora griseola resistance loci in common beans

“…Crous & Braun, is one of the most serious diseases of common bean in tropical and subtropical countries and losses in the crop due to ALS can be as high as 80% (Stenglein et al 2003;Miklas et al 2006;Crous et al 2006;Singh and Schwartz 2010). More than 40 races of P. griseola have been identified (Wagara et al 2004;Nay et al 2019a) and a successful resistance breeding strategy requires a thorough understanding of the host-pathogen interaction and the characterization of genetic and phenotypic resistance (Correa-Victoria et al 1989;Liebenberg and Pretorius 1997).…”

“…The use of fungicides to control ALS is an efficient measure; however, it is expensive mainly for smallholder farmers (Nay et al 2019a). The most cost-effective and environmentally friendly management strategy to control the disease is through resistant cultivars (Pastor-Corrales et al 1998).…”

New Andean source of resistance to anthracnose and angular leaf spot: Fine-mapping of disease-resistance genes in California Dark Red Kidney common bean cultivar

“…To identify sources of resistance against the ANT pathogen, a panel of 14 Andean cultivars were screened for their reactions to ten Mesoamerican (9,64,65,73,89,445,453,1545,2047, and 3481) and six Andean (2,7,19,23,39, and 55) races of C. lindemuthianum ( Table 1). The genomic locations of the known Co genes in each cultivar, except for Jalo Vermelho, Jalo Pintado 2, and CDRK (Table 1), have been previously reported [25,28,29,30,31,32,53].…”

A half century of a bean breeding program in the South and Alto Paranaíba regions of Minas Gerais

“…The UFLA program has therefore also opted to conduct RS to accumulate the greatest possible number of resistance alleles. The RS program for resistance to angular leaf spot (Pseudocercospora griseola) is the oldest, having been created in 1998 (Nay et al 2019). It was followed by the RS program for resistance to white mold (Sclerotinia sclerotiorum) (Leite et al 2016) and, more recently, resistance to anthracnose (Colletotrichum lindemuthianum) (Costa et al 2019).…”