Common bean (Phaseolus vulgaris
L.) is one of major plant protein sources for human food. Several
diseases affect its yield and quality. Common bacterial blight (CBB), caused by
Xanthomonas campestris pv. Phaseoli (Xap), is a seed born disease.
One major source of resistance for CBB derived from tepary
bean (P. acutifolius) was introduced
into common bean. A major CBB resistance QTL, derived
from XAN159 and originally from tepary bean line
PI319443, is carried in germplasms HR45 and HR67 developed from our bean
breeding program. Results showed that this major QTL can explain about 50%
phenotypic variation. Five markers, including SCAR UBC420, STS333a, STS330c,
STS283c and SSR PV-tttc001, were identified tightly linked to this major QTL
within 5 cM. They were located on the distal region of chromosome 1L. Given the
intensive utilization of this major CBB resistance QTL in breeding programs in
the