Genetic Diversity Analysis Of Cherry Tomato Germplasm Resources Based On Morphological、SSR And SNP Markers

Genetic background is becoming increasingly due to constantly selected and aggregated excellent trait of cherry tomatoes.In this study,54 cherry tomatos germplasm resources were collected used as test materials,using phenotypic traits combined with SSR and SNP to analyze the genetic diversity.First marked by Mi and then used an orthogonal experimental design of L16(45)to optimized practical molecular makers PCR reaction system of cherry tomato,and used this result to test disease resistance of 54 cherry tomatoes,final result will used for genetic diversity of phenotypic traits.Variation analysis and correlation analysis were performed on 15 quantitative traits,and genetic diversity index was calculated for 15 quality traits.The principal component analysis was performed on 18 traits with abundant variability,comprehensive evaluation analysis of 54 cherry tomatoes started on these basis.Cited the 24 pairs SSR makers of patent of Beijing academy of agriculture and forestry,Used 3500 Genetic Analyzer to test genetic diversity of 54 cherry tomatoes.374 pairs of SNP primers were used to detected the genotype of 54 accessions of cherry tomato germplasm.145 pairs of highly polymorphic SNP primers were screened for 54 cherry tomato genotypes.The results showed as follows:1.Practical molecular makers PCR reaction system of cherry tomato(20 μL)showed as follows:0.5μmol/L primer,1.5 mmol/L Mg2+,0.3 mmol/L dNTPs,480ng template DNA and 1.0 U Taq DNA polymerase.Optimum annealing temperature is 56℃,Optimum cycle times is 33.screened out which has at least one resident disease from 53 materials as high-multi resistance materials.2.The results showed that there were large genetic differences among the 15 quantitative traits,and the correlations among different traits were complex.58 mutation types were detected in 16 quality traits,indicating that genetic diversity of 54 cherry tomato germplasms were abundant.Among the 18 traits with abundant variation types,the cumulative contribution rate of the first 8 principal components is 80.6%.Highest D-value is in NO.36 material.The 54 materials which at Euclidean distance of 0.93 divided into seven major groups.The first group includes 24 materials,Materials in this group performed better,mostly are round fruit,single fruit weight is heavier,soluble solid basically over 7,2 ventricles and pink fruits,and there were 10 kinds of materials resistant to two or more diseases.3.Based on the genetic diversity of SSR markers,73 alleles were detected and per locus at an average detected 3.042.Shannon diversity index is 0.807,and the PIC is 0.412 on average.According to the genetic similarity coefficient differences between germplasm resources,54 germplasm resources were divided into 5 major groups at a genetic similarity coefficient of 0.67,of which the first and second groups all included 2 materials.The third group includes 12 materials,the fourth group includes 34 materials,and the fifth group includes 4 materials.Based on the population structure analysis of 54 cherry tomato germplasm resources by SSR markers,54 cherry tomato germplasm resources were roughly divided into 3 groups(Pop Ⅰ,Pop Ⅱ and Pop Ⅲ),of which Pop Ⅰ group included 21 materials,The Pop Ⅱ taxa consisted of 13 materials and the Pop Ⅲ taxa consisted of 20 materials.4.145 pairs were selected from 374 pairs of SNP primers used to detected genotype of 54 cherry tomato germplasm.The results showed that 422 alleles were detected,and an average of 2.897 per locus.PIC varied from 0.260 to 0.375.At the genetic distance of 0.25,54 cherry tomato germplasms were divided into 5 groups.The first group includes 16 materials,the second group includes 14 materials,the group Ⅲ includes 20 materials,the groupⅣ includes 3 materials,and the group Ⅴ includes 1 material.Based on SNP molecular markers,the population structure of 54 cherry tomato germplasm resources was analyzed and divided into 3 groups and Pop Ⅰ included 20 materials,Pop Ⅱ included 21 materials,Pop Ⅲincluded 13 materials.Through the above results we can explicit the comprehensive characteristics of various traits,and provide a theoretical basis for the improvement of cherry tomato varieties.