Authors: M J Asins V Raga D Roca A Belver E A Carbonell
Publish Date: 2015/01/28
Volume: 128, Issue: 4, Pages: 667-679
Abstract
The present study approaches the QTL dissection of rootstock effects on a commercial hybrid variety grafted on a population of RILs derived from Solanum pimpinellifolium genotyped for 4370 segregating SNPs from the SolCAP tomato panel and grown under moderate salinity Results are compared to those previously obtained under high salinity The most likely functional candidate genes controlling the scion Na+ were rootstock HKT11 and HKT12 as it was previously reported for nongrafted genotypes The higher fruit Na+ found when rootstock genotype was homozygote for SpHKT1 supports the thesis that scion HKT1 is loading Na+ into the phloem sap in leaves and unloading it in sink organs A significant increment of small mostly seedless fruits was found associated with SlHKT1 homozygous rootstocks Just grafting increased the incidence of blossom end rot and delayed fruit maturation but there were rootstock RILs that increased commercial fruit yield under moderate salinity The heritability and number of QTLs involved were lower and different than those found under high salinity Four large contributing 17 rootstock QTLs controlling the leaf concentrations of B K Mg and Mo were detected whose 2 Mbp physical intervals contained B K Mg and Mo transportercoding genes respectively Since a minimum of 3 QTLs two of them coincident with leaf K and Ca QTLs were also found governing rootstockmediated solublesolids content of the fruit under moderate salinity grafting desirable crop varieties on stresstolerant rootstocks tenders an opportunity to increase both salt tolerance and qualityThis work was supported in part by grants from the Spanish Government AGL200800197/AGR RTA201100132C02 and the European Union FP7KBBE20115 contract 289365 ROOTOPOWER Authors thank UNIGENIA BIOSCIENCE SLU for the grafting labor Dr AJ Monforte IBMCP Valencia Spain for comprehensive access to information on SolCAP SNPs and Dr GP Bernet IBMCP Valencia Spain for technical assistance
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