Genetic Mapping of thepvr1Locus inCapsicumspp. and Evidence That Distinct Potyvirus Resistance Loci Control Responses That Differ at the Whole Plant and Cellular Levels

Abstract

Two unlinked, recessive loci have been characterized in Capsicum spp. that independently confer distinct types of resistance to pepper mottle potyvirus (PepMoV). The first locus, from C. annuum cv. Avelar, affected the spread of PepMoV through the plant and had no discernible effect on tobacco etch potyvirus (HAT isolate; TEV-HAT) infection (J. F. Murphy and M. K. Kyle, Phytopathology 85:561-566, 1995). The second locus, found in C. chinense PI 159236 and PI 152225, interfered with PepMoV and TEV-HAT infection in plants and in isolated protoplasts. The resistant responses displayed by the C. chinense accessions to PepMoV and TEV-HAT appeared indistinguishable; however, these accessions were both susceptible to a second isolate of TEV, TEV-Mex21. We propose the symbols pvr1 for recessive PepMoV and TEV resistance from the C. chinense accessions and pvr3 for recessive PepMoV resistance from Avelar. pvr1 has been genetically mapped to a small linkage group with synteny to the short arm of tomato chromosome 3.

Recessive resistance genes against potyviruses are localized in colinear genomic regions of the tomato (Lycopersicon spp.) and pepper (Capsicum spp.) genomes

“…Among the potyvirus resistance genes mapped on the pepper genome (Table 1), we focussed on the pvr2/pvr5 locus because it shares strong similarities with pot-1: both are recessive loci involved in resistance to both PVY and TEV. The resistance mechanism controlled by pvr2 varies from restriction of cell-to-cell movement to inhibition of viral coat protein accumulation (Arroyo et al 1996;Deom et al 1997;Murphy et al 1998). Similarly, PVY was not detected in the inoculated leaves of pot-1 plants using ELISA tests and back-inoculation on susceptible hosts, suggesting that virus multiplication and/or cell-to-859 Fig.…”

“…In pepper, at least seven major genes (named pvr for potyvirus virus resistance; Kyle and Palloix 1997) and several QTLs have been characterized. Genetic mapping using molecular markers allows us to identify two clusters: the first one, localized on a pepper genomic region colinear to tomato chromosome 3, includes the recessive genes pvr1, pvr2 and pvr5 and a major-effect QTL (Caranta et al 1997;Murphy et al 1998;Caranta, unpublished results); the second ones involves the two dominant genes Pvr4 and Pvr7 mapped on a pepper genomic region colinear to tomato chromosome 10 ( Grube et al 2000b). Another striking feature of the potyvirus resistance genes is that most of them are involved in resistance to two or more related potyviruses.…”

Genetic variation and covariation for resistance and tolerance to Cucumber mosaic virus in Mimulus guttatus (Phrymaceae): a test for costs and constraints

“…Extreme resistance occurs in those interactions in which the plant does not allow detectable amounts of viral accumulation within individual inoculated cells (Murphy et al, 1998). Resistance may restrict virus movement from one cell to the next, resulting in localization of the virus or allow movement within but not out of the inoculated leaf (Dawson and Hilf, 1992;Hull, 2002;Ponz and Bruening, 1986).…”

Development of RAPD and SCAR markers linked to the Pvr4 locus for resistance to PVY in pepper (Capsicum annuum L.)

“…in the last few years. The loci pvr1 (Murphy et al 1998), pvr2 (Caranta et al 1997), pvr6 and Pvr7 , conferring different spectra of resistances against several potyviruses, have been tagged with different molecular markers and following different location strategies. In the case of Pvr4, two different strategies, using AFLPs and RAPDs, were designed in order to obtain useful markers for MAS.…”