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Analyse des variations de poids et de teneurs en sucres du fruit de tomate par une approche intégrative combinant des études écophysiologique, génétique et moléculaire

Abstract : Fruit weight and sugar content are two complex traits largely involved in tomato quality. The aim of this study is to dissect these two traits via a multidisciplinary approach combining ecophysiology, genetics and genomics. A population of 20 introgression lines of Solanum chmielewskii in the genetic background of S. lycopersicum were grown in 2006 and 2007 under two fruit load conditions in order to modulate carbon availability to fruit. Under high load conditions, trusses were not pruned while under low load conditions, trusses were pruned to one fruit. Indicators of ecophysiological processes involved in tomato fruit weight and sugar content were measured or estimated and allowed the characterization of main processes underlying QTL for quality traits such as cell division and expansion, fruit transpiration or allocation of carbon for the synthesis of structural compounds. A high effect of fruit load was emphasized on QTL expressions, indicating the occurrence of genotype x fruit load interactions. The combined use of an ecophysiological model predicting the final fruit sugar content and QTL detection allowed the identification of co-localizations between QTL for quality traits and QTL for variables involved in fruit functioning such as the assimilate supply to the fruit, the metabolic transformation of sugars into other compounds, or the dilution by water uptake. Finally, an introgression line harbouring QTL for fresh weight and sugar content with opposite allele effects, and the line conferring the genetic background were studied at the transcriptome level during the cell expansion phase. Candidate genes whose expression levels could be associated to the variation of weight and sugar content led by a fruit load change were identified. The kinetic analysis of expressions from a set of candidate genes allowed establishing links between ecophysiological and molecular variables.
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https://tel.archives-ouvertes.fr/tel-00600410
Contributor : Marion Prudent <>
Submitted on : Tuesday, June 14, 2011 - 5:24:30 PM
Last modification on : Thursday, December 3, 2020 - 4:46:02 PM
Long-term archiving on: : Thursday, March 30, 2017 - 11:40:14 AM

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  • HAL Id : tel-00600410, version 1

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Marion Prudent. Analyse des variations de poids et de teneurs en sucres du fruit de tomate par une approche intégrative combinant des études écophysiologique, génétique et moléculaire. Biologie végétale. Université d'Avignon, 2009. Français. ⟨tel-00600410⟩

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