title: Yield quantitative trait loci from wild tomato are predominately expressed by the shoot.
abstract: Plant yield is the integrated outcome of processes taking place above and below ground. To explore genetic, environmental and developmental aspects of fruit yield in tomato, we phenotyped an introgression line (IL) population derived from a cross between the cultivated tomato (Solanum lycopersicum) and a wild species (Solanum pennellii). Both homozygous and heterozygous ILs were grown in irrigated and non-irrigated fields and evaluated for six yield components. Thirteen lines displayed transgressive segregation that increased agronomic yield consistently over 2 years and defined at least 11 independent yield-improving QTL. To determine if these QTL were expressed in the shoots or the roots of the plants, we conducted field trials of reciprocally grafted ILs; out of 13 lines with an effect on yield, 10 QTL were active in the shoot and only IL8-3 showed a consistent root effect. To further examine this unusual case, we evaluated the metabolic profiles of fruits from both the homo- and heterozygous lines for IL8-3 and compared these to those obtained from the fruit of their equivalent genotypes in the root effect population. We observed that several of these metabolic QTL, like the yield QTL, were root determined; however, further studies will be required to delineate the exact mechanism mediating this effect in this specific line. The results presented here suggest that genetic variation for root traits, in comparison to that present in the shoot, represents only a minor component in the determination of tomato fruit yield.
authors.affiliation: The Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Gur
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Semel
authors.forename: Sonia
authors.initials: S
authors.lastname: Osorio
authors.forename: Michael
authors.initials: M
authors.lastname: Friedmann
authors.forename: Saleh
authors.initials: S
authors.lastname: Seekh
authors.forename: Bilal
authors.initials: B
authors.lastname: Ghareeb
authors.forename: Ayed
authors.initials: A
authors.lastname: Mohammad
authors.forename: Tzili
authors.initials: T
authors.lastname: Pleban
authors.forename: Gabi
authors.initials: G
authors.lastname: Gera
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Dani
authors.initials: D
authors.lastname: Zamir
mesh_terms: D032461:Chromosomes, Plant; D018556:Crops, Agricultural / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D055864:Droughts; D005638:Fruit / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D018745:Genome, Plant; D005838:Genotype; D006824:Hybridization, Genetic; D007557:Israel; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D040641:Quantitative Trait Loci