Organization of Genes Conferring Resistance to Anthracnose in Common Bean - Translational Genomics for Crop Breeding: Biotic Stress - page 167

(identity unknown). Using a backcross popula-
tion (Ms 8 Eo 2 /Corel), the RVI gene was mapped
at the end of linkage group P4 (Adam-Blondon
et al. 1994b), which corresponds to Pv04 of the
bean core map (Freyre et al. 1998). The associ-
ation of the RVI gene with other characterized
resistance genes on Pv04 has not been possible
due to the lack of molecular markers linked to
this gene common to both linkage maps, and the
absence of the original resistance source and
anthracnose race.
The single dominant anthracnose resistance
gene Mexique 1 (renamed as Co-3 gene) was first
described in the Mesoamerican cultivar Mexico
222 by Bannerot et al. (1971) as a gene confer-
ring resistance against isolates 14 and 51. The
resistance to race Ebnet (corresponding to race
Kappa or 31) present in Mexico 222 was ana-
lyzed by Fouilloux (1976) and assumed to be
conferred by the Co-3 gene. Resistance to race
31 present in Mexico 222 was directly mapped
in Pv04, closely linked to specific anthracnose
resistance genes effective against races 19 and
38 in the F 2:3 population, Mexico 222 x Widusa
(Rodrıguez-Suarez et al. 2008). This suggests
that the original Co-3 gene from Mexico 222
is in fact a cluster of linked resistance genes
each conditioning resistance to different races
of C. lindemuthianum . This resistance cluster is
flanked by the markers SW12, and Pv-ctt001,
and OAH18 1100/600 .
The differential cultivar Widusa was consid-
ered to belong to the Andean gene pool, but
pedigree evidence suggests a stronger relation-
ship with Mesoamerican gene pool (Gon¸alves-
Vidigal and Kelly 2006). Using the F 2:3 popu-
lation Mexico 222 x Widusa, a gene conferring
specific resistance to races 65, 73, 102, and 449
(no recombination was observed) was located
on Pv04, tightly linked to the resistance genes
from Mexico 222 protecting against races 19,
31, and 38 mapped in this same F 2:3 population
(Rodrıguez-Suarez et al. 2008). This indicates
that cultivars Mexico 222 and Widusa carry dif-
ferent haplotypes of the same Co-3 resistance
cluster on Pv04.

Breeding line BAT93 (derived from [Veranic
2 x PI207262] x [Jamapa x Great Northern Tara])
is the parent of the B/J mapping population.
The Co-9 gene conferring resistance to C. lin-
demuthianum strains 38, C531, E29b, E33c, E4,
and E42b was first described in BAT93 and was
directly mapped to the distal position of Pv04
using the RIL population B/J (Geffroy et al.
1999, 2008).
The Co-z gene from JaloEEP558 conferring
resistance against C. lindemuthianum strain 80
was mapped to Pv04 in the B/J RIL population.
A second resistance gene from JaloEEP558, the
Co-y gene conferring resistance against C. lin-
demuthianum strains M38, A47, 88, E25, 40,
3616, and 82, was mapped to Pv04, tightly linked
to Co-z (Geffroy et al. 1999, 2009). The Co-y
gene co-segregate with the Co-9 gene mapped
in BAT 93 in this same RIL population, indicat-
ing that Co-y , Co-z , and Co-9 are closely linked
race-specific genes of the Co-3 resistance cluster
located on Pv04.
A gene present in breeding line A493
(obtained from Alubia x BAT 93) that con-
ferred resistance against race 38 was mapped to
Pv04 using the F 2:3 population Andecha x A493
(Mendez-Vigo et al. 2005). This resistance gene
is closely linked to the SW12 and OAH18 1100
markers, suggesting that its relative position on
Pv04 corresponds to the Co-3 cluster in Mex-
ico 222. From the results of different allelism
tests, Mendez-Vigo et al. (2005) demonstrated
that the previously considered independent genes
Co-3 and Co-9 could be alleles at the same locus
or, based on the current knowledge about the
organization of the anthracnose resistance loci,
could be two closely linked race-specific genes
of the same resistance cluster. The Co-9 gene
present in BAT93 was renamed Co-3 3 by the
Genetics Committee of the Bean Improvement
Cooperative.
Resistance to races 6, 38, 39, and 357 in breed-
ing line A252 (Carioca x Guanajuato 31) was
investigated in a F 2:3 population derived from
the cross Andecha (S) x A252 (R). A cluster of
four genes conferring specific resistance against