The Late Blight Resistance Locus Rpi-blb3 from Solanum bulbocastanum Belongs to a Major Late Blight R Gene Cluster on Chromosome 4 of Potato

Abstract

Late blight, caused by Phytophthora infestans, is one of the most devastating diseases in cultivated potato. Breeding of new potato cultivars with high levels of resistance to P. infestans is considered the most durable strategy for future potato cultivation. In this study, we report the identification of a new late-blight resistance (R) locus from the wild potato species Solanum bulbocastanum. Using several different approaches, a high-resolution genetic map of the new locus was generated, delimiting Rpi-blb3 to a 0.93 cM interval on chromosome 4. One amplification fragment length polymorphism marker was identified that cosegregated in 1,396 progeny plants of an intraspecific mapping population with Rpi-blb3. For comparative genomics purposes, markers linked to Rpi-blb3 were tested in mapping populations used to map the three other late-blight R loci Rpi-abpt, R2, and R2-like also to chromosome 4. Marker order and allelic conservation suggest that Rpi-blb3, Rpi-abpt, R2, and R2-like reside in the same R gene cluster on chromosome 4 and likely belong to the same gene family. Our findings provide novel insights in the evolution of R gene clusters conferring late-blight resistance in Solanum spp.

Dynamics of senescence-related QTLs in potato

“…A wide range of functional genes involved in resistance against various pathogens have been reported on chromosome 4, among others a major late blight resistance gene cluster (Celebi-Toprak et al 2002;Li et al 1998;Park et al 2005;ZimnochGuzowska et al 2000).…”

“…In our study, haulm senescence was assessed at several time points during the growing season on a diploid potato mapping population evaluated for two consecutive years in Finland (2004 and2005). We are presenting here an alternative two-step approach: modeling first in a flexible way the curve trajectories with a smoothed generalized linear model (GLM) procedure.…”

Progress in Mapping and Cloning Qualitative and Quantitative Resistance Against Phytophthora infestans in Potato and Its Wild Relatives

“…The majority of S. demissum blight resistance genes (R1 to R11), have been mapped (Table 1), and are primarily located on linkage groups (LG) IV (R2), V (R1) and XI (R3a, R3b and R5-R11) (Leonards-Schippers et al 1992;Li et al 1998;Huang et al 2004;Park et al 2005a;Bradshaw et al 2006a). Following the observation that the race-specific R genes from S. demissum did not confer durable resistance to P. infestans, extensive screening programmes of potato gene banks for new sources of resistance have been conducted.…”

“…Rpi-blb3 has previously been mapped to LG IV and appears to be part of a large cluster of R genes comprising R2 from S. demissum, R2-like from an S. demissum-free background and Rpi-abpt from S. bulbocastanum (Park et al 2005a;Park et al 2005b). Functional orthologues of Rpi-blb3 have been identified in these species by allele mining.…”

The novel, major locus Rpi-phu1 for late blight resistance maps to potato chromosome IX and is not correlated with long vegetation period

“…The Wrst two alleles were identiWed on chromosome VIII and independently cloned by two research groups-RB (Naess et al 2000;Song et al 2003) and Rpi-blb1 (Van der Vossen et al 2003). The second gene Rpi-blb2 is localized on chromosome VI and has also been cloned , whereas Rpi-blb3 has been mapped to chromosome IV (Park et al 2005a). The latter forms an R gene cluster on chromosome IV, together with R2, Rpi-abpt from S. bulbocastanum and a R2-like gene of unknown origin (Park et al 2005b).…”