Three QTLs for Botrytis cinerea resistance in tomato

FINKERS, R, VAN DEN BERG, P, VAN BERLOO, R. TEN HAVE, A, VAN HEUSDEN, A, VAN KAN, J AND LINDHOUT, P.

THEORETICAL AND APPLIED GENETICS

Año: 2007 vol. 114 p. 585 - 593

0040-5752

<!-- @page { size: 21cm 29.7cm; margin: 2cm } P { margin-bottom: 0.21cm } --> Tomato (Solanum lycopersicum) is susceptible to grey mold (Botrytis cinerea). Partial resistance to this fungus was identiWed 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 F2 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 pheno- typic variation. Both QTL eVects were conWrmed by assessing disease resistance in two BC2S1 progenies segregating for either of the two QTLs. One additional QTL, Rbcq4 on Chromosome 4 reducing DI, was iden tified in one of the BC2S1 progenies. F2 individuals, homozygous for the Rbcq2 and Rbcq4 alleles of S. hab rochaites showed a reduction of DI by 48%. QTLs from S. habrochaites LYC4 oVer good perspectives for breeding B. cinerea resistant tomato cultivars.