Genomic analysis of wild tomato (Solanum pennellii) introgressions determining metabolic- and yield-associated traits

ASIS R, KAMENETZKY L, BASSI S, DE GODOY F, BERMÚDEZ L, FERNIE AR, VAN SLUYS MA, VREBALOV J, GIOVANNONI JJ, ROSSI M AND CARRARI F

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Año: 2010 vol. 152 p. 1771 - 1786

0032-0889

With the aim of determining the genetic basis of metabolic regulation in tomato fruit, we constructed a detailed physical mapof genomic regions spanning previously described metabolic quantitative trait loci of a Solanum pennellii introgression linepopulation. Two genomic libraries from S. pennellii were screened with 104 colocated markers from five selected genomicregions, and a total of 614 bacterial artificial chromosome (BAC)/cosmids were identified as seed clones. Integration ofsequence data with the genetic and physical maps of Solanum lycopersicum facilitated the anchoring of 374 of these BAC/cosmid clones. The analysis of this information resulted in a genome-wide map of a nondomesticated plant species and covers10% of the physical distance of the selected regions corresponding to approximately 1% of the wild tomato genome.Comparative analyses revealed that S. pennellii and domesticated tomato genomes can be considered as largely colinear. A totalof 1,238,705 bp from both BAC/cosmid ends and nine large insert clones were sequenced, annotated, and functionallycategorized. The sequence data allowed the evaluation of the level of polymorphism between the wild and cultivated tomatospecies. An exhaustive microsynteny analysis allowed us to estimate the divergence date of S. pennellii and S. lycopersicum at 2.7million years ago. The combined results serve as a reference for comparative studies both at the macrosyntenic and microsynteniclevels. They also provide a valuable tool for fine-mapping of quantitative trait loci in tomato. Furthermore, they will contribute toa deeper understanding of the regulatory factors underpinning metabolism and hence defining crop chemical composition.