Genetic Diversity And Genetic Relationship Analysis On Lagenaria Siceraria (Molina.) Standley With RAPD And ISSR Markers

Bottle gourd (Lagenaria siceraria (Molina.) Standley) is an important vegetable. After a long-term evolution and breeding, there were rich varieties in China. The study on the genetic diversity of bottle gourd benefits the collection, conservation, identification and reasonable use of the germ plasm. In this study, The RAPD and ISSR makers were used to detect the genetic diversity and cluser analysis on 38 Bottle Gourd accessions. The cluster analysis and the main coordinates analysis were applied to study the genetic relationship and diversity of the accessions. The main results were as follows:1. Based on the previous research, considering traits of bottle gourd and all the other factors, the method about extraction and purification of bottle gourd genetic DNA was set. The method was simple, high efficient.2. Using the research results of other cucurbitaceous plants, the RAPD and ISSR amplification programs were optimized to set up the reaction system of RAPD and ISSR fitting for analyzing the resources of bottle gourd with the orthogonal diagram and gradient PCR test.3. Twenty primers of 10 base pair were choosen from 200 random primers and were used to analyze among 38 accessions with RAPD which generated 203 bands, of which polymorphic bands number was 104, the percentage of polymorphism equaled 51.2%. 12 primers, which could amplified clearly bands, were selected out from 40 ISSR primers. As a result,115 bands were generated, and polymorphic bands number was 96,the percentage of polymorphism was 83.5%.4. The correlation between RAPD and ISSR (r=0.784, n=703) indicating that the two methods were rather highly consistant and suitable for detecting genetic diversity and genetic relationships in bottle gourd, but some accessions still clustered different between the two markers.5. 38 accessions were clustered into 3 groups and 8 subgroups based on the RAPD data by the method of clustering analysis, and 3 groups and 13 subgroups by the method of principal coordinates analysis. ISSR data clusters 38 accessions into 5 groups and 8 subgroups by the method of clustering analysis, and 4 groups and 10 subgroups by the method of principal coordinates analysis. The results indicated that the RAPD and ISSR markers were enough to cluter the 38 bottle gourd accessions.6. According to the clustering analysis of the RAPD results, it was clear that the genetic similarity index was 0.22-0.94. According to the clustering analysis of the ISSR results, it proved that the genetic similarity index was 0.25-0.96. The results from RAPD and ISSR markers showed obvious correlation with the agronomic characteristics classification and the locations distribution of the Bottle Gourd accessions. The genetic diversity, similarity and genetic relationships of local bottle gourd accessions in different distinctions of China were presented.