Diversity Of Kernelled Apricot (Armeniaca Vulgaris Lam.) Using Simple Sequence Repeat

Kernelled apricots, as unique fruit trees in China, their genetic background and genetic relationship remained unclear because of lacking of research efforts in contrast with abundance of resources. In this study, the SSR marker was used to analyze apricot resources with an attempt to provide some molecular evidences for collection, maintenance, and the origin and migration of kernelled apricots.The suitable 20μL SSR reaction system was established by orthogonal design and single factor analysis, and the system contained: Mg²⁺ 1.5 mmol/L, dNTPs 0.2 mmol/L, Taq DNA polymerase enzyme 1.5 U, primers 0.25μmol/L. Two DNA templates were used to screen 22 pairs of primers developed and selected from peach (Amygdalus persica Linn.) and apricot (Armeniaca vulgaris Lam.). 19 of these primer pairs resulted in correct amplifications and 3 primers were given up for failure or non-specific amplification after agarose gel electrophoresis.Molecular size of PCR products showed difference among individuals at every locus not by 2 % agarose gel electrophoresis but with polyacrylamide gel electrophoresis. Therefor non-denaturing polyacrylamide gel electrophoresis condition was optimized as follows: gel concentration of 6 % polyacrylamide (acrylamide/methylene bisacrylamide ratio 29:1), 1²Î¼L PCR product per aperture after 27 cycles, electrophoresis at 1 000 V for 2 h. Seven of nineteen primers were abandoned based on farther requirement of SSR-PAGE analysis for that those primers resulted in non-polymorphism or vague bands.28 accessions, containing 25 accessions of kernelled apricot and 3 edible apricots, have been analyzed with 12 effective primers. A total of 101 alleles were detected for the 12 loci, with a mean of 8.417. According to analysis of SSR data by software Popgene,the PIC(polymorphism information content) among 12 primers ranged from 0.4546 to 0.8645, and the difference of observed heterozygosity and expected heterozygosity among 12 primers ranged from 0.0318 to 0.3884, which indicated that there were high genetic diversity in kernelled apricots.UPGMA cluster analysis of apricots by method with NTSYS pc 2.11 software showed consistent genetic relationship approximately with that obtained from morphological marker. However, according to the dendrogram,'Guoren','Youren'and'Fengren'which were derived from'Yiwofeng'showed obvious difference from'Yiwofeng'respectively.'Weixuan 1'was revealed the same genotype with'80B05', as well as'You 1'with'No. 2', which were conflicting with the traditional classification. So the origin of these individuals still need further study.