Dynamic Qtl Mapping Of Soluble Solid Content And Related Traits In Tomato

Object:Tomato SSC solid content is a complex and important quantitative traits, is a nuclear inheritance, is not affected by the cytoplasm, showing additive effects. SSR markers are used for constructing the genetic linkage map of tomato, and tomato SSC solid content and associated quality traits are for initial dynamic QTL. This provides a theoretical basis of tomato varieties for our marker-assisted selection breeding and quality trait loci for positional cloning.Methods:This study used 166 F2 populations from the cross between TD22 and HT-1-1-1-1 which are processing tomato and fresh eating tomato respectively, derivatived from single seed for dynamic QTL research, SSR molecular markers are used for studying QTL. The expression of SSC is a dynamic process, in order to fully understand the QTL genetic effects, we should not only know their genetic given point in time the role, but also to understand their dynamic expression. Analysis using dynamic models to analyze the phenotypic values of SSC solids with time-varying function model, to detect changes in dynamic traits influence the process of major genes. In this study, three tomato fruit development period (green ripe stage, yellow ripe stage and the red ripe stage) for dynamic positioning QTL.Results:1.Though the analysis of quality traits of F2:3 family lines which are derived from TD22 and HT-1-1-1-1, every quality trait which is controlled by multiple genes is in accordance with in line with normal quality traits. There are some correlation among the traits of tomato quality. SSC are positively correlated with SSC sugar but negatively correlated with fruit weight (FW) in green ripe stage. SSC are positively correlated with SSC sugar and organic acid in yellow ripe stage. SSC are positively correlated with SSC Sugar and organic acid but negatively correlated with fruit weight in red ripe stage. Through the progressively lines regression analysis, we constructed lines regression equation. Green ripe stage: Y=4.727-0.002 X1+1.089 X2; Yellow ripe stage:Y=4.420+1.924X2+0.274X3; Red ripe stage: Y=5.592-0.003 X1+0.9824 X2+0.294 X3. X1, X2, X3 stand for single fruit weight, SSC sugar and organtic acid.2.500 Tomato SSR primers are used for parents screening and 107 reproducible polymorphic SSR primers are selected. We constructed F2 population which is from the cross between processing tomato TD22 and fresh-eating tomato, constructing genetic linkage map, including 5 linkage groups and 88 markers. The length of linkage groups ranges from 19.082 to 118.178 cM, marker number 2 to 77. The average distance is 2.33 cM, the shortest distance is 0.09 cM, covering 214.36 cM.3. The genome is QTL scanned using composite interval mapping (CIM), SSC and related traits are QTL located in the development of tomato fruit in the year of 2009. The three periods were detected on SSC of 4,0 and 8 QTLs; detected on the fruit weight of 2,3, and 2 QTLs; detected on the fruit shape index of 1,0 and 0 QTL; detected on the sugar 1,1 and 5 QTLs; detected on the organic acids of 0,1 and 1 QTL; not detected on the VC of QTL.Conclusion:1. SSC is significantly correlated with associated traits among different periods; sugar is a main factor of SSC.2. Linkage groups in this study, a total of five, the number of linkage group markers in the three following two. In the same linkage group, and some markers of genetic distance, reaching more than 30 cM, close to the free exchange of value. Thus, markers in the genome on the distribution of loose, this situation may be due to many.3. Marker LEaat006å'ŒTomato TC162363 were detected both in green ripe stage and red ripe stage, indicating the process of developing tomato fruit of some tomato SSC associated with quantitative trait genes have been expressed, ripening period is not detected QTL may be due to fewer markers covering the genome, only five linkage groups, but may appear in the other linkage groups. Meanwhile three periods detected QTL experiences a dynamic change, indicating the expression of quantitative trait loci by time and space. Tomato TC162363 and LEaat006, which LEaat006 in green ripe stage and red ripe stage of the contribution rate reaches 10% or more, will will provide some help in marker assisted selection.