BAC-derived markers converted from RFLP linked to Phytophthora capsici resistance in pepper (Capsicum annuum L.)
Hyoun-Joung. K Ki-Taek. K Byoung-Cheorl. K Seok-Hyeon. N Heung-Ryul. L Gi-Bo. Y Choi. D Kweon. O. Y
Theory of Applied Genetics ; 2008 [Vol.118] Pages:15-27
Abstract
Phytophthora capsici Leonian, an oomycete pathogen, is a serious problem in pepper worldwide. Its resistance in pepper is controlled by quantitative trait loci (QTL). To detect QTL associated with P. capsici resistance, a molecular linkage map was constructed using 100 F2 individuals from a cross between Capsicum annuum CM334 and C. annuum Chilsungcho. This linkage map consisted of 202 restriction fragment length polymorphisms (RFLPs), 6 WRKYs and 1 simple sequence repeat (SSR) covering 1482.3 cM, with an average interval marker distance of 7.09 cM. QTL mapping of Phytophthora root rot
and damping-oV resistance was performed in F2:3 originated from a cross between resistant Mexican landrace C. annuum CM334 and susceptible Korean landrace C. annuum Chilsungcho using composite interval mapping (CIM) analysis. Four QTL explained 66.3% of the total phenotypic variations for root rot resistance and three 44.9% for damping-oV resistance. Of these QTL loci, two were located close to RFLP markers CDI25 on chromosome 5 (P5) and CT211A on P9. A bacterial artiWcial chromosome (BAC) library from C. annuum CM334 was
screened with these two RFLP probes to obtain sequence information around the RFLP marker loci for development of PCR-based markers. CDI25 and CT211 probes identified seven and eight BAC clones, respectively. Nine positive BAC clones containing probe regions were sequenced and used for cytogenetic analysis. One single-nucleotide amplified polymorphism (SNAP) for the CDI25 locus, and two
SSRs and cleaved amplified polymorphic sequence (CAPS) for CT211 were developed using sequences of the positive BAC clones. These markers will be valuable for rapid selection of genotypes and map-based cloning for resistance genes against P. capsici.
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