| 41 different varieties(strains) of Loropetalum chinense var. rubrum were chosen as the research materials. DNA from those materials was extracted by Modified CTAB method. Based on the optimal reaction suitable for ISSR-PCR amplification, ISSR marker was used to construct the DNA fingerprint of those different varieties. The results were as follows:Single-factor experimental design was applied to establish the optimal reaction system for ISSR-PCR which was 20μL reaction volume. It included 1U Taq DNA polymerase, 1.5mmol/L Mg2+, 50ng template DNA,0.24 mmol/L dNTP, 0.50μmol/L primer. Amplification program was 3min at 94℃; 45sec at 94℃, 1 min at 51-57℃, 1.5min at 72℃, 35 cycles, then 5min at 72℃and stored at 4℃.There were 14 primers selected from 60 primers, which were applied in genetic diversity and systematic relationships. The number of amplified fragments was 203 while the number of polymorphic fragments was 148. The percentage of polymorphic fragments was 72.9%. The similarity coefficients among 41 L. chinense species was between 0.626 and 0.926, Average was 0.75. Using NTSYS-pc version 2.10e get an UPGMA dendrogram. All the materials were divided into 2 groups with the threshold of 0.72 of similarity coefficient, 5 groups with the threshold of 0.74 of similarity coefficient. The results showed that clustering results coincide with three groups of the morphological classification. There was a trend of traditional varieties and later varieties bred belonging to different cluster. It appeared transition type among the three groups. With the increase of GS, the clustering trend was not entirely consistent with the morphological classification,The 41 varieties'DNA fingerprint,which bands was very rich and clearly discernible,has been constructed by using ISSR marker. |
