The Research Of Seeds Purity Identification And Fingerprint Construction In Watermelon Hybrids

The paper conducted research on watermelon first-filial generation seed purityidentification through using the technique of SSR molecular markers, and comparedwith the result of field identification, succeed in constructing a set of highly effective、accurate and reliable SSR seed purity identification method, at same time, it alsoconducted research on the construction of sixteen watermelon finger-print, andanalysed genetic similarity coefficient and cluster. The main research results asfollows:1.Comparing six treatment combinationes of CTAB-seed leaves、CTAB-maturedleaves、CTAB-seeds、SDS-seed leaves、SDS-matured leaves and SDS-seeds，theresearch indicated that the method of watermelon DNA extracted by CTAB methodwas better than SDS method, and the DNA extracted from leaves was better thanseeds.2.The PCR reaction system adapted to watermelon seed purity identification: thetotal reaction volume was25μl, containing2μl of25mmol/L Mg2+、0.2μl of5U TaqDNA polymerase、1.5μl of10pmol/L forward and reverse primers respectively、1.5μlof2.5mmol/L dNTPs、2.5μl of10×Reaction Buffer、1～2μl of50ng/μl templateDNA, then added ddH2O to25μl; The outputs of PCR was shown throughelectrophoresis on12%polyacrylamide gel at constant voltage (90V) for2.5hours.3.Comparing four silver staining methods, the result indicated that the methodfour had fewer chemical reagents、lower cost、shorter time of staining and developinglighter background and clearer strap than the first three methods.4.Eighty-eight pairs of SSR primers were selected from watermelon hybrid andits female parent, among these, there were three highly stability and betterrepeatability SSR primers performed polymorphisms, then compared the results oftwo methods, and found two results were absolutely accordance, the accuracy rate ofSSR identification method is100percent.5.The establishment of watermelon hybrids finger-print: Through thecombination of six polymorphism primers, succeed in dividing sixteen watermelonhybrids into three broad categories, their genetic similarity coefficient range were0.363between0.864, average at0.641, then constructed the digital finger-print of sixteen watermelon hybrids.