Zooming in on a quantitative trait for tomato yield using interspecific introgressions

Science. 2004 Sep 17;305(5691):1786-9. doi: 10.1126/science.1101666.


To explore natural biodiversity we developed and examined introgression lines (ILs) containing chromosome segments of wild species (Solanum pennellii) in the background of the cultivated tomato (S. lycopersicum). We identified Brix9-2-5, which is a S. pennellii quantitative trait locus (QTL) that increases sugar yield of tomatoes and was mapped within a flower- and fruit-specific invertase (LIN5). QTL analysis representing five different tomato species delimited the functional polymorphism of Brix9-2-5 to an amino acid near the catalytic site of the invertase crystal, affecting enzyme kinetics and fruit sink strength. These results underline the power of diverse ILs for high-resolution perspectives on complex phenotypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Aspartic Acid
  • Catalytic Domain
  • Crosses, Genetic
  • Flowers / enzymology
  • Flowers / genetics
  • Fruit / enzymology
  • Fruit / genetics
  • Gene Expression
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genetic Complementation Test
  • Lycopersicon esculentum / enzymology
  • Lycopersicon esculentum / genetics*
  • Lycopersicon esculentum / growth & development
  • Molecular Sequence Data
  • Polymorphism, Single Nucleotide*
  • Quantitative Trait Loci*
  • Quantitative Trait, Heritable
  • Solanum / enzymology
  • Solanum / genetics*
  • Sucrose / metabolism
  • Transcription, Genetic
  • Transformation, Genetic
  • beta-Fructofuranosidase / chemistry
  • beta-Fructofuranosidase / genetics*
  • beta-Fructofuranosidase / metabolism*


  • Aspartic Acid
  • Sucrose
  • beta-Fructofuranosidase