An estimation of SSR alleles numbers for analyzing genetic diversity of apricot

【Objective】To analyze the impact of SSR alleles number on the genetic relationships in apri-cot.【Methods】All of the 55 SSR loci were used to test the genetic relationship among the 140 apricot ac-cessions. The similarity matrix of the general alleles(877) and those of different numbers of alleles from100 to 800 were compared by the methods of Mantel correlation test.【Results】We detected the 877 allel-ic variations in these SSR loci. The correlations coefficient between the sub-matrix and the general matrixdisplayed an upward tendency with increased numbers of alleles. There was good fit when the numbers ofalleles exceeded 575. The number of alleles required(Y) was significantly associated with the number ofsample(X) for good fit,and the regression equation was Y=149.5 ln(X/12) +200.2.【Conclusion】The trulygenetic relationship of apricot accessions could be obtained from enough alleles using SSR markers. Thisequation could be used to calculate the number of SSR alleles required for a genetic relationship study inapricot. The SSR primers might be selected according to well-proportioned distribution of the SSR loci inthe apricot genome.