Abstract: 【Objective】As a perennial woody fruit tree, mango has the problems of high genomic heterozygosity, unclear self-compatibility and hybridization affinity of most breeding parents, and low seed setting rate of artificial pollination, which brings some difficulties to the selection of parents for mango hybrid breeding.As a new type of molecular marker, SSR markers are mainly used in genetic diversity analysis, genetic relationship analysis and fingerprint construction in mango, but the use of SSR markers to identify the true and false hybrids of mango F1 has not been reported.In this study, 13 varieties were selected as parental materials, and SSR technology was used to detect the true and false hybrids and analyze the genetic characteristics of 1001 F1 progeny plants with the breeding objectives of large fruit, red, high solid content, high yield and stable yield, which provided theoretical guidance for clarifying the hybridization affinity of mango breeding parents and the selection of breeding parents.【Methods】he 13 mango varieties Guifei, Jinhuang, Tainong No.1, Baixiangya, Hongyu, R2E2, Yexiang, Tommy, Kate, Villard, Nanjomai, Juile and A61 were mixed and planted for natural pollination.The mature fruits were harvested from the fruiting mother tree. The mother varieties included 12 varieties such as Guifei, Tainong No.1, Jinhuang, Juile, Nandoumai, Yexiang, Villard, R2E2, Tommy, Hongyu, A61 and Kate. The seedlings were obtained after sowing.Punch the leaves with a puncher and take 100 mg of fresh tissue.The DNA of mango F1 generation was extracted by magnetic bead genomic DNA extraction kit, and the concentration and purity of DNA were detected by ultraviolet spectrophotometer and 1 % agarose gel electrophoresis，PCR products were detected by agarose gel electrophoresis ( 1 % concentration ) and capillary fluorescence electrophoresis.In the previous transcriptome data of mango, 200 pairs of primers were selected for screening, and 200 pairs of primers were synthesized by using each parent as the template of DNA. The screened primers were used for SSR analysis.The genetic parameters such as number of alleles ( Na ), number of effective genes ( Ne ), observed heterozygosity ( Ho ), expected heterozygosity ( He ), fixation index ( F ) and Shannon 's information index ( I ) were calculated by Cervus software；The polymorphism information index ( PIC ) was calculated by GenALEx6.0 software, and the genetic differentiation coefficient was obtained;Structure was used to analyze the genetic structure of the population and the genetic diversity of mango F1 generation；The unweighted pair-group method with arithmetic means ( UPGMA ) was used to cluster the populations of mango fruit offspring by using the selected SSR core primers.【Results】 Thirteen pairs of primers with stable amplification and clear bands were screened, and 13 loci with good polymorphism and stability were determined. The PIC value was between 0.314 and 0.741, and the polymorphism of the loci was high.The number of alleles ranged from 3 to 9, with an average of 6.154. The average effective number of alleles ( Ne ) was 2.557, Shannon 's information index ( I ) was 1.078, observed heterozygosity ( H0 ) was 0.571, expected heterozygosity ( He ) was 0.579, and polymorphism information content ( PIC ) was 0.526；UPGMA cluster analysis showed that when the genetic similarity coefficient was 0.50, it could be divided into three groups, which was basically consistent with the results of population structure analysis.Compared with other varieties, the alleles of mango varieties GF, YX and Juile were more evenly distributed in the population, the average Shannon 's information index ( I ) was higher, and Juile was the lowest, indicating that the genetic diversity in the GF population was higher and the population differentiation was the highest;The genetic differentiation between GF and Juile was obvious, and the genetic differentiation between the other varieties was small;The female parent was the F1 progeny of GF, JH, KT, TN, A61, Juile and KT. The true hybrid rate was more than 50 %, and the true hybrid rate of JH, TN and A61 was as high as 80 %;In terms of expected heterozygosity and observed heterozygosity, the heterozygosity of TN, KT, Juile, JH, HY and GF was also relatively high, and the true heterozygosity of NDM, R2E2, HY, Villard and YX was low, which was 25 %, 13.71 %, 25.15 %, 33.33 % and 36.36 %, respectively.【Conclusion】Through the Fst results among varieties, it was found that the genetic differentiation between HY and R2E2, HY and YX, HY and NDM, Juile and R2E2, Juile and NDM, GF and NDM, GF and Juile was obvious, and the genetic differentiation between the remaining varieties was small；SSR identification of mango F1 generation showed that the cross compatibility of mango varieties TN, KT, Juile, JH, HY and GF was strong, while the cross compatibility of NDM, R2E2, HY, Villard and YX varieties was weak, which was easy to self-fertilize, and there were many alleles among the varieties, and the genetic diversity was rich.
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