QTL Mapping And Association Study For Aromatic Compounds In Grape(Vitis Vinifera L.)

Aroma substance is a complex trait controlled by many genes,and it is affected by the factors such as cultivation techniques,environment,and it also related to the genotype and genetics in grapevine.It is difficult to essentially reveal the genetic mechanism of aroma by using traditional research methods.Linkage mapping based on pedigree and association study of natural population is now the main approaches to the study of the quantitative traits in plants.A grapevine hybrid population was derived from a crossing of the female parent cultivar ’87-1’ and male parent cultivar ’9-22’.A total of 149 plants were selected from the hybrid population as the mapping population.SSR and SRAP analysis were used for constructed molecular genetic maps of the parents,and the major aroma substances were conducted in QTL analysis in grapevine.On the other hand,assosiation study of polymorphism of gene in different varieties and aroma characteristics to explore functional SNP based on VvDXS gene and a-TPS gene in 92 varieties.The major results were as follows:1.Analysis of crossing of the ’87-1’ and ’9-22’ and varieties population in aroma,We found that hybrid groups with transgressive segregation on linalool,citronellol,nerol,geraniol.and geraniol acid,but a-terpineol was not;In varieties population test,there is large difference distribution of aroma in varieties population.Linalool dispersed over 0-5μg/kg and>25μg/kg;citronellol,nerol distribution more uniform among concentration range;a-Terpineol,geraniol.and geraniol acid dispersed between 0-5μg/kg.2.Genetic maps were constructed by ’87-1’ and ’9-22’,generating 156 maternal special markers.142 paternal special markers and 215 common markers allocating into 19 linkage groups.The femal genetic maps contained 308 markers covered a total length of 2017.9 cM,with a mean distance between adjacent markers of 6.55cM.The male genetic maps contained 295 markers covered a total length of 1803.3 cM,with a mean distance between adjacent markers of 6.11 cM.3.QTL detection for six aroma substances was done by software MapQTL 5.0.48 QTLs were detected associated with aroma in genetic maps.Majority of QTLs were in LG3 and LG5.Lin14-1、Lin15-1、a-Ter15-1、Citl4-1、Ner15-2and Gerl5-1 were found between VMC1A5 and VMC2E7 in LG3.HDR gene which in monoterpenes metabolic pathway were found in this area by physical location of markers.On the other hand，Linl4-3,a-Ter15-2,Nerl5-3,Ger15-2 and Ger acid14-1 were found between VLG5-C-1 and UDV106 in LG5.DXS gene which in monoterpenes metabolic pathway were found in this area.4.P852 and P1678 were associated with 6 aroma among 22 SNP site in VvDXS gene.P852(G/T)with high concentration of linalool，α-terpineol,nerol,and geraniol acid.P1678(A/A)with high concentration of linalool,a-terpineol,citronellol,nerol,geraniol,and geraniol acid.P1678(A/G)may not belong to neutral varieties.5.We can conclude by analysis of association between a-TPS and a-terpineol that S1556 were associated with a-terpineol,and it would effect concentration of a-terpineol in grapevine.P1556(C/T)with high concentration of a-terpineol.