Construction Of DNA Fingerprint Database And Identification Of Cultivar For Grape

Grape is one of important economic fruit crop in China,so the preservation,research,and utilization of grape germplasm resources are of great significance to the breeding of new varieties.However,with the homogeneity in the process of breeding,the genetic differences between grape varieties are becoming less,and it is difficult to distinguish on the basis of their phenotypic characteristics.In recent years,with the development of biotechnology,DNA fingerprint database constructed by DNA molecular marker technology is of prime importance for cultivar identification.The approach as an assistive tool of DUS tests can improve the efficiency and accuracy in the selection of similar cultivar,and accelerate the testing process.In this study,we selected out a set of SSR core primers with high polymorphism to analyze 296 grape cultivars in China and constructed the DNA fingerprint database,which provides a scientific basis for the cultivar identification and genetic analysis.The main results are as follows:1.38 of 140 pairs of SSR primers were screened out based on 24 accessions distinct in genetic background.Then 9 pairs SSR primers which come from the 38 pairs were used for DNA fingerprint database construction,cultivar identification,and genetic diversity analysis.2.208 alleles were amplified with 9 SSR primers among the 296 grape cultivars,of which the polymorphic loci were 208 and the ratio of polymorphism was 100%.Alleles amplified by each pair of primer ranged from 17 to 32,the average was 23.11,the size of the amplified fragment ranged from 121 bp to 289 bp,and the number of genotypes ranged from 64 to 116 at per locus.The Polymorphic information content values(PIC)ranged from 0.77 to 0.88,the mean value was 0.83.3.The result of cluster analysis with UPGMA showed that 243 diploid materials could be divided into two groups,that is Subgen.Euvitis Planch.and Subgen.Muscadinia Planch.,and the former were also divided into eight small groups which belong to wild species and two group which belong to cultivar.53 polyploid materials were divided into 3 groups.The clustering results are in good agreement with the family tree basically.4.In this study,the case of homonyms(3 groups)and synonyms(9 groups)are existent,such as,Hongputao-Xinjiang and Hongputao,Lvmunage and Munage,Yiliputao and Hetianhong,Heiputao-xinjiang and Zihongxingputao.5.The DNA fingerprint database of 296 grape cultivars was constructed by using 9 SSR core primers.The fingerprint database showed that 7 pairs of primers which were VVMD28,VVMD7,VrZAG79,VrZAG62,VVS2,VVMD27 and VVMD32 could distinct all of the 296 cultivars basically.