Organization of Genes Conferring Resistance to Anthracnose in Common Bean - Translational Genomics for Crop Breeding: Biotic Stress - page 168

the four C. lindemuthianum races was mapped
at the end of Pv04, tightly linked to the markers
SW12 and OAH18 1100 (Rodrıguez-Suarez et al.
2007), which flank the Co-3 resistance cluster.
In the Andean cultivar MDRK, two genes
conferring specific resistance against races 449
and 1545 were mapped to Pv04 in a F 2:3 pop-
ulation derived from the cross TU x MDRK
(Campa et al. 2009). These resistance loci are
probably part of the Co-3 cluster based on their
closely linked relationship with the Pv-ctt001
marker (Campa et al. 2009; Rodrıguez-Suarez
et al. 2008). The presence of specific resistance
genes from MDRK at the Co-3 resistance clus-
ter is of considerable interest as this differential
cultivar has been generally used in allelism tests
as a resistance source of the Co-1 gene. Accord-
ing to current research, monogenic segregation
observed from the differential cultivar MDRK
could be controlled by a gene located at either
the Co-1 or the Co-3 cluster, and is necessary
to select a specific anthracnose race to compare
before conducting allelism tests with MDRK.
In the cultivar Kaboon, a cluster formed by at
least seven genes conferring specific resistance
to races 3, 7, 19, 31, 449, 453, and 1545 were
mapped to Pv04 in the F 2:3 population Kaboon
x Michelite (Campa et al. 2011). The gene con-
ferring specific resistance against race 31 shows
a complementary mode of action, so the pres-
ence of other complementary resistance genes
is necessary for the resistance response. This
resistance cluster present in Kaboon is tightly
linked to Pv-ctt001 marker, so based on its map
location it would correspond to Co-3 cluster. As
with MDRK, Kaboon had been used in allelism
tests as resistance source of the Co-1 gene, so
researchers are cautioned to know which genes
they are comparing based on judicial selection
of anthracnose races used for screening.
The Co-10 gene was described in the com-
mercial cultivar Ouro Negro as a single gene
conferring resistance against races 23, 64, 73, 81,
and 89 (Alzate-Marin et al. 2003) and, to date,
it has been only been identified in this geno-
type. A gene in Ouro Negro conferring resis-

tance against one of these anthracnose races
(not specified by the authors; Alzate-Marin et al.
2003) was located on Pv04 based on its link-
age relationship with the SCAR marker SCF10.
The RAPD marker OF10 1072 , from which the
SCAR SCF10 was developed, was mapped on
Pv04 in a relative position corresponding to
the Co-3 resistance cluster (Kelly et al. 2003;
Rodrıguez-Suarez et al. 2005; Perez-Vega et al.
2012). However, Co-10 was reported as inde-
pendent from Co-9 (included in cluster Co-3 on
Pv04) based on the segregation ratio observed
against race 89 corresponding to the presence of
three independent resistance genes in the F 2 pop-
ulation Ouro Negro (R) x PI 207262 (R): Co-4 3
and Co-9 genes reported in PI207262 (Alzate-
Marin et al. 2007) and a gene independent from
those in Ouro Negro. In the interpretation of the
allelism tests conducted by Alzate-Marin et al.
(2003), the possibility that the monogenic seg-
regation observed against races 23, 64, 73, 81,
and 89 could be conferred by different single
genes—one linked to the SCF10 SCAR in Pv04
and the other independent from Co-3 gene—was
not considered. To confirm the assumption that
monogenic segregation observed against differ-
ent races are controlled by the same gene in
a genotype, co-segregation analyses should be
done. The independence between the Co-10 gene
and resistance genes included in the Co-3 cluster
should be investigated.

LinkageGroupPv07

Genes conferring specific resistance to differ-
ent races of C. lindemuthianum were mapped
to the central position of Pv07 in the Middle
American genotypes TU, SEL1360, G2333, and
AB136 (Figure 9.2). In the anthracnose differen-
tial cultivar TU, eight closely linked genes con-
ferring specific resistance to races 3, 6, 7, 31,
38, 39, 102, and 449 were mapped to a cen-
tral position of Pv07 using the F 2:3 population
TU x MDRK (Campa et al. 2009). This resis-
tance cluster appears to correspond to the Co-5
gene, first named as Mexique 3 and described