Three QTLs for Botrytis cinerea resistance in tomato.
Tomato (Solanum lycopersicum) is susceptible to grey mold (Botrytis cinerea). Partial resistance to this fungus was identified in accessions of wild relatives of tomato such as S. habrochaites LYC4. In order to identify loci involved in quantitative resistance (QTLs) to B. cinerea, a population of 174 F(2) plants was made originating from a cross between S. lycopersicum cv. Moneymaker and S. habrochaites LYC4. The population was genotyped and tested for susceptibility to grey mold using a stem bioassay. Rbcq1, a QTL reducing lesion growth (LG) and Rbcq2, a QTL reducing disease incidence (DI) were identified. Rbcq1 is located on Chromosome 1 and explained 12% of the total phenotypic variation while Rbcq2 is located on Chromosome 2 and explained 15% of the total phenotypic variation. Both QTL effects were confirmed by assessing disease resistance in two BC(2)S(1) progenies segregating for either of the two QTLs. One additional QTL, Rbcq4 on Chromosome 4 reducing DI, was identified in one of the BC(2)S(1) progenies. F(2) individuals, homozygous for the Rbcq2 and Rbcq4 alleles of S. habrochaites showed a reduction of DI by 48%. QTLs from S. habrochaites LYC4 offer good perspectives for breeding B. cinerea resistant tomato cultivars.
Finkers
Richard
R
Graduate school Experimental Plant Sciences, Laboratory of Plant Breeding, Wageningen University, PO box 386, 6700 AJ, Wageningen, The Netherlands. Richard.Finkers@wur.nl
van den Berg
Petra
P
van Berloo
Ralph
R
ten Have
Arjen
A
van Heusden
Adriaan W
AW
van Kan
Jan A L
JA
Lindhout
Pim
P
D020171:Botrytis; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D007113:Immunity, Innate / Q000235:genetics*; D018551:Solanum lycopersicum; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D040641:Quantitative Trait Loci