Races of Colletotrichum lindernuthianum and implications for bean breeding in Uganda

Abstract

SUMMARY Nineteen local isolates of the bean anthracnose pathogen have been obtained and tested over the period 1964–70 for pathogenicity on a set of differential cultivars including the sets of four cultivars each used in the alternative systems of Schreiber and Hubberling and of Bannerot and Blondet. The results indicate the existence of a number of races not conforming to those of either system and the ability, when freshly collected, of some isolates with affinities to both α and β races partially to overcome the immunity of the cultivar Cornell 49–242. The implications of the position as now known from these results and a review of the literature for disease‐resistance breeding are discussed. Tests of the Uganda isolates, on a range of other dry bean cultivars, indicate a tendency for α and δ races to be pathogenic on small‐seeded indeterminate viny or indeterminate bush cultivars, whereas β and γ races tend to be pathogenic on larger‐seeded and determinate cultivars.

A Comprehensive Review of the Major Genes Conditioning Resistance to Anthracnose in Common Bean

“…Origin: The Co-2 gene originally known as the Are gene, was fi rst described by Mastenbroek (1960) in the black bean genotype Cornell 49-242 from Venezuela (Tables 1 and 2). The Co-2 gene conditions resistance to four races (alpha-17, beta-130, gamma-102 and delta-23) of C. lindemuthianum and was widely deployed as a resistance gene in both dry and snap bean breeding programs on all continents (Fouilloux, 1979;Leakey and Simbwa-Bunnya, 1972;Tu, 1992). Initially, the Co-2 was considered a 'horizontal' type resistance because it provides resistance to many races of the pathogen (Tu, 1992), but race specifi city of the Co-2 was detected as new virulent races rapidly emerged (Hubbeling, 1976(Hubbeling, , 1977.…”

“…Initially, the Co-2 was considered a 'horizontal' type resistance because it provides resistance to many races of the pathogen (Tu, 1992), but race specifi city of the Co-2 was detected as new virulent races rapidly emerged (Hubbeling, 1976(Hubbeling, , 1977. The extensive deployment of the Co-2 gene resulted in the failure of this gene to provide resistance in North America (Kelly et al, 1994;Tu, 1994), South America (Balardin et al, 1997;Menezes and Dianese, 1988;Pastor-Corrales et al, 1995), Europe (Fouilloux, 1976(Fouilloux, , 1979Hallard and Trebuchet, 1976;Hubbeling, 1976Hubbeling, , 1977Kruger et al, 1977), and Africa (Leakey and Simbwa-Bunnya, 1972).…”

Pathogenic Variation of Colletotrichum lindemuthianum causing Anthracnose of Beans (Phaseolus vulgaris) in Uganda

“…Seven of these races were reported for the first time in Burundi. In Uganda, Leaky and Simbwa-Bunnya (1972) using differential cultivars from Shreiber and Hubberling, identified races 17, 19, 23, 102, 130, and 453 with isolates collected from Central, Western and South Western regions of Uganda. More recently, races 23,55,102,130,227,375,511 and 767 were reported from Kabale, Kisoro, Bushenyi and Mpigi districts with race 767 reported as the most widespread and virulent (Nkalubo, 2006).…”

Genomics, genetics and breeding of common bean in Africa: A review of tropical legume project

“…Gene pyramiding has been suggested to provide resistance to a wide range of the ALS pathotypes (Miklas, Kelly, Beebe, & Blair, ; CIAT, 2007). Bean anthracnose is a highly variable pathogen, new pathotypes reportedly keep emerging time after time (Leaky and Simbwa‐Bunya, ; Nkalubo, ; Pastor‐Corrales & Tu, ). Resistance to this pathogen is conditioned by nine independent resistances ( Co1‐Co‐10 ).…”