Are the polygenic architectures of resistance to Phytophthora capsici and P. parasitica independent in pepper?

Abstract

The pepper accession Criollo de Morelos 334 is the most efficient source of resistance currently known to Phytophthora capsici and P. parasitica. To investigate whether genetic controls of resistance to two Phytophthora species are independent, we compared the genetic architecture of resistance of CM334 to both Phytophthora species. The RIL population F5YC used to construct the high-resolution genetic linkage map of pepper was assessed for resistance to one isolate of each Phytophthora species. Inheritance of the P. capsici and P. parasitica resistance was polygenic. Twelve additive QTLs involved in the P. capsici resistance and 14 additive QTLs involved in the P. parasitica resistance were detected. The QTLs identified in this progeny were specific to these Phytophthora species. Comparative mapping analysis with literature data identified three colocations between resistance QTLs to P. parasitica and P. capsici in pepper. Whereas this result suggests presence of common resistance factors to the two Phytophthora species in pepper, which possibly derive from common ancestral genes, calculation of the colocation probability indicates that these colocations could occur by chance.

Identification of isolate‐specific resistance QTLs to phytophthora root rot using an intraspecific recombinant inbred line population of pepper (Capsicum annuum)

“…In previous studies, QTLs for phytophthora root rot resistance against different pathogen isolates from different geographic regions have been identified on chromosome 5; for example, a major QTL was identified for resistance against strains S101 and S197 (Thabuis et al. , 2004), or isolate Pc197 (Bonnet et al. , 2007).…”

Identification and Expression Analysis of Candidate Genes Associated with Defense Responses to Phytophthora capsici in Pepper Line “PI 201234”

“…Based on these genetic models, different quantitative trait loci (QTL) have been reported, with the most consistent results indicating that the QTLs on chromosome P5 have major roles in pepper P. capsici resistance [6,13,14,15,16,17,18,19,20,21]. Recently, CaDMR1 , a candidate gene that encodes a homoserine kinase, was reported to be highly associated with the major QTL Pc5.1 [22].…”

The inheritance of late blight resistance derived from Solanum habrochaites

“…For clean tomato cultivation, using resistant cultivars is a desirable alternative to chemical control. The development of crops that possess durable genetic resistance provides the best prospect for efficient, economical and environmentally safe control of late blight (Mizubuti 2005, Bonnet et al 2007). …”