Abstract: 【Objective】The genetic diversity and relationship of Xinjiang apricot varieties (lines) were studied at molecular level by ISSR, and the DNA fingerprinting database was also established. The result of the study will give the cross breeding, classification and the identification some guidance. 【Method】Six materials with different phenotypes were selected to screen the characteristic primers from 100 ISSR primers which were have clear stripe and main band, rich polymorphism, repeatability, and the varieties with high resolution. The genetic diversity of 48 Xinjiang apricot varieties (lines) were analyzed by POPGENE version 1.32, the number of polymorphism and the percentage of polymorphic loci were calculated, the number of alleles, effective number of alleles, Nei's genetic diversity and Shannon information index, and genetic relationship were analyzed by NTSYS pc version2.10e as well as the Nei’s genetic similarity coefficient (GS) and the genetic distance (GD). By using the characteristics, specific band of different primer combinations combined with Gel2.0 fingerprint automatic identification system, the apricot varieties (lines) in Xinjiang were identified, and the standard fingerprint database of apricot varieties (lines) was built using Gel2.0 fingerprint automatic identification system.【Result】Four ISSR primer pairs that with high polymorphism and good repeatability were selected from 100 ISSR primer pairs, and their names name respectively are UBC809, UBC836, UBC844 and UBC850 and they are regarded as specific primers. Four primer pairs produced 78 loci of which 73 were polymorphic. The percentage of polymorphic loci was 93.13%. UBC844 has the highest percentage of polymorphic loci of 100%. The average value of observed number of alleles, effective number of alleles, Nei’s genetic diversity and Shannon information index were 1.9313, 1.4368, 0.2622 and 0.4028, respectively, showing that the genetic diversity of all varieties (lines) was relatively abundant. The similarity coefficient of P. armeniaca cv. Huangrouyouxing and P. armeniaca cv. Dawuyuexing was 0.8846, genetic distance was 0.1226. The similarity coefficient of P. armeniaca cv. Kumanti and P. armeniaca cv. Suogejianali was 0.5641, and the genetic distance was 0.5725. Combine two different combinations of 4 primers could quickly and accurately identify 46 apricot varieties (lines). Only P. armeniaca cv. Lajiaoxing and P. armeniaca cv. Yiliakeyulvke need three primer combinations to be identified. A characteristic DNA fingerprint database of 48 apricot varieties (lines) was constructed by using the 4 ISSR primers with Gel2.0 fingerprint automatic identification system. 【Conclusion】The genetic diversity of apricot varieties (lines) in Xinjiang was relatively abundant and genetic relationship was relatively close. The genetic relationship of P. armeniaca cv. Huangrouyouxing and P. armeniaca cv. Dawuyuexing was the closest, but the genetic relationship of P. armeniaca cv. Kumanti and P. armeniaca cv. Suogejianali was the farthest. The results indicated that ISSR marker is suitable for the analysis of genetic diversity, relationship and construction of DNA fingerprinting database of Xinjiang apricot varieties (lines). Moreover, the fingerprinting database will provide a basis for identification, authenticity and purity of apricot varieties (lines), and provide a scientific basis for the registration, registration protection and intellectual property rights of new variety.

Key words: Xinjiang apricot varieties (lines), genetic diversity, DNA fingerprint database