Development and Application of a Cleaved Amplified Polymorphic Sequence Marker ( Phyto ) Linked to the Pc5.1 Locus Conferring Resistance to Phytophthora capsici in Pepper ( Capsicum annuum L.).

Phytophthora capsici causes destructive disease in several crop species, including pepper ( Capsicum annuum L.). Resistance in this species is physiologically and genetically complex due to many P. capsici virulence phenotypes and different QTLs and R genes among the identified resistance sources. Several primer pairs were designed to follow an SNP (G/A) within the CA_011264 locus linked to the Pc5.1 locus. All primer pairs were designed on DNA sequences derived from CaDMR1 , a homoserine kinase (HSK), which is a gene candidate responsible for the major QTL on chromosome P5 for resistance to P. capsici . A panel of 69 pepper genotypes from the Southern Seed germplasm collection was used to screen the primer pairs designed. Of these, two primers ( Phyto _for_2 and Phyto _rev_2) surrounding the SNP proved successful in discriminating susceptible and resistant genotypes when combined with a restriction enzyme ( BtgI ). This new marker (called Phyto ) worked as expected in all genotypes tested, proving to be an excellent candidate for marker-assisted selection in breeding programs aimed at introgressing the resistant locus into pure lines.