Genetic Diversity Of 13 Ornamental Peach By RAPD And ISSR

In this study,we took two methods that is RAPD and ISSR molecular markers,the genetic diversity of 13 varieties of ornamental peaches were analyzed.The purpose is to provide a theoretical basis in utilization of germplasm resources of ornamental peach plants, species identification and breeding of new varieties.The results were as follows:1. Four methods for DNA extractiong were compared,including High salt low Ph method, CTAB method, nuclear DNA method and SDS method.we found:CTAB method was the best,because the DNA yield and its purity is very high,the DNA color is white and the DNA is qualified for RAPD and ISSR.2. The suitable reaction system of ornamental peach plants using RAPD technology were found.PCR reaction were carried out in 25μl volumes containing per reaction.10×buffer 2.5μl,20ng template DNA,1.5mmol/L Mg2+,0.8μmol/L primer, 0.3mmol/L dNTPs, TaqDNA polymerase 2.0U.PCR reactions were carried out under the following programme conditions:45 cycles at 94℃for 4min(predenaturation), 94℃for 1min (denaturation),37℃for 1min (annealing); 72℃for 2min(extension); 72℃to continue to extend lOmin,4℃Save for ever.3. The suitable reaction system of ornamental peach plants using ISSR technology were found.PCR reaction were carried out in 25μl volumes containing per reaction.10×buffer 2.5μl,40ng template DNA,2.5mmol/L Mg2+,0.4μmol/L primer, 0.4mmol/L dNTPs, TaqDNA polymerase 0.5U.PCR reactions were carried out under the following programme conditions:40 cycles at 94℃for 4min(predenaturation), 94℃for 1min (denaturation),52℃for lmin (annealing),72℃for 2min(extension); 72℃to continue to extend 10min,4℃Save for ever.4.15 primers which amplified 272 repeatable loci (including 243 polymorphic loci) were screened out of 60 primers.The percentage of polymorphic bands was 89.34%.The long of fragments are between 200bp and 4000bp,mostly between 400bp and 2000bp.The RAPD fingerprints of ornamental peach plants from 15 primers can identify ornamental peach plants cultivars exactly.5.15 primers which amplified 278 repeatable loci (including 251 polymorphic loci) were screened out of 60 primers.The percentage of polymorphic bands was 90.28%.The long of fragments are between 200bp and 4000bp,mostly between 400bp and 2000bp.The RAPD fingerprints of ornamental peach plants from 15 primers can identify ornamental peach plants cultivars exactly.6. According to RAPD and ISSR markers, Genetic similarity of 13 varieties of ornamental peaches were computed and and cluster analysis diagram is drawn..According to genetic similarity coefficients and the cluster analysis diagram of the Ornamental peaches, we Obtained genetic diversity analysis between 13 varieties of ornamental peach:13 ornamental peach varieties were first divided into two categories, one class of materials is longevity peach, and the other class materials are non-longevity peach, Including direct branches weeping peach and peach class. then under the tree, flower, leaf and petal-type ornamental,peach cultivars will be classified as vertical and straight sticks, daisy type, type of rose and peony type, peach and green peach leaves, univalve and plena. UPGMA cluster analysis revealed that the morphological classification of ornamental peach cultivars was consistent.