Plant Genome I Conference
Town & Country Conference Center, San Diego, CA, November, 1992.
PG-I: GENOMIC LOCALIZATION OF MONOGENIC DOMINANT RESISTANCE TO BEAN
COMMON MOSAIC VIRUS IN Phaseolus vulgaris
GENOMIC LOCALIZATION OF MONOGENIC DOMINANT RESISTANCE TO BEAN
COMMON MOSAIC VIRUS IN Phaseolus vulgaris
Maria J. Zimmermann and C. Eduardo Vallejos, Department of
Horticultural Sciences and Plant Molecular and Cellular Biology
Group, University of Florida, Gainesville, FL 32611.
Dominant resistance to bean common mosaic virus (BCMV) is
controlled by the I gene in common beans. This gene has been
incorporated into most modem bean cultivars because the virus is
widely distributed. Genotypes carrying the I gene either display
no transmissible mosaic symptoms or a hypersensitive response
upon inoculation with necrosis inducing strains of BCMV and four
other related potyviruses (BICMV, CAbMV, SMV and WMV-2). The
objectives of this project are to determine the genomic
localization of the I gene and to construct a high density map
around the gene. Such a map will eventually facilitate molecular
cloning of the I gene via chromosome walking techniques. We have
analyzed the segregation of an F2 progeny between a BCMV
resistant (II) Mesoamerican line ('A30l') and a susceptible (ii)
Andean cultivar ('Calima'). The parental lines display allelic
differences at a few morphological loci and at a large number of
molecular marker loci. In addition, the expression of double
stranded RNAs is also segregating in this progeny. The phenotype
at the I locus was determined after inoculation of detached
leaves with fresh inoculum preparations of strain type NL3 of
BCMV.
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