QTL analysis of resistance to bacterial wilt caused by <i>Ralstonia solanacearum</i> in potato

Abstract

Ralstonia solanacearum causes bacterial wilt, a soil-borne disease and one of the most important maladies of potato and other Solanaceae crops. We analyzed the resistance of a potato clone to bacterial wilt by quantitative trait locus (QTL) analysis. A resistant diploid potato clone 10-03-30 was crossed with a susceptible diploid clone F 1-1 to generate a diploid, two-way pseudo-testcross F 1 population comprised of 94 genotypes. Dense linkage maps, containing 4,139 single nucleotide polymorphism markers with an average distance of 0.6 and 0.3 cM between markers, were constructed for both parents. The resistance level was evaluated by in vitro inoculation test with R. solanacearum (phylotype I/biovar 4/race 1). Five QTLs (qBWR-1 to-5) were identified on potato chromosomes 1, 3, 7, 10, and 11, and they explained 9.3-18.4% of the phenotypic variance. The resistant parent had resistant alleles in qBWR-2, qBWR-3, and qBWR-4 and susceptible alleles in qBWR-1 and qBWR-5. Accumulation of the resistant alleles in all five QTLs increased the level of resistance compared with that of the resistant parent. This is the first study to identify novel QTLs for bacterial wilt resistance in potato by using genome-wide markers.

GRP genes in potato genome and their expression response to phytohormone and Ralstonia solanacearum

“…GRP can be used as antimicrobial protein in plant nature defence response (Halder et al, 2019). In previous reports, potato growth and development were affected by R. solanacearum under various stresses (Habe et al, 2019; Kim et al, 2005). To further clarify the putative roles of GRPs in potato response to biotic stresses, we examined the expression patterns of StGRP1 under R. solanacearum infection via qRT‐PCR.…”

Identification and characterization of resistance quantitative trait loci against bacterial wilt caused by the Ralstonia solanacearum species complex in potato

“…A genetic map (Habe et al 2019) was previously constructed using single-nucleotide polymorphism (SNP) markers. Since both diploid parents were highly heterozygous, the segregating population was considered a twoway pseudo testcross population (Grattapaglia and Sederoff 1994) and the parental maps were constructed.…”

“…1ab). qBWR-6b was considered to be derived from RP 10-03-30, a haploid clone of Saikai 35 (Habe et al 2019), which was originally derived from S. phureja (Mori et al 2012). S. phureja is a well-known source of BW-resistant factors, and the resistance is strainspeci c and sensitive to high temperatures (Sequeira and Rowe 1969;Sequeira 1979;Ciampi and Sequeira 1980;French and De Lindo 1982).…”

“…We previously identi ed resistance QTLs against the phylotype /biovar 4 strain on chromosomes 1, 3, 7, 10, and 11 using a diploid mapping population consisting of S. tuberosum, S. chacoense, and S. phureja (Habe et al 2019). In this study, we assayed the same diploid population using different strains (phylotypes I and IV or biovars 3, 4, and 2A) at different incubation temperatures (24°C and 28°C) after inoculation and performed QTL analysis.…”

Potato plants transformed with the Arabidopsis EF-Tu receptor (EFR) show restricted pathogen colonization and enhanced bacterial wilt resistance under conditions resembling natural field infections

“…Instead, available sources of resistance are usually polygenic, being difficult to transfer into desirable cultivars. Although quantitative trait loci (QTL) associated with BW resistance have been found in tomato (19) (20) (21) , tobacco (22) , eggplant (23) and potato (24) , resistant commercial cultivars are not yet available.…”