Analysis of genetic diversity of sugar beet genotypes using random amplified polymorphic DNA marker

摘要

Plant breeding programs are formulated based on the diversity and selection of superior quantitative and qualitative traits. Hence, assessment of genetic diversity is the first step of every plant breeding program. In this regard, use of new methods for studying genetic diversity seems necessary. In the present study, the genetic diversity of thirty sugar beet genotypes was determined using Random Amplified Polymorphic DNA (RAPD) marker. Following the DNA extraction and optimization of experiment conditions, of the 40 primers under study, 10 primers that induced polymorphism and produced good and clear bands in the genotypes of sugar beet were randomly selected. Statistical calculations were carried out based on the Jaccard similarity coefficient and UPGMA-based grouping in the NTSYS software (version 2.02). The amplitude of the multiplied bands varied between 100 and 3000 of alkaline pair. The polymorphism of all primers was 82.33% within the similarity limit. The Cophenetic coefficient for the similarity matrix and the resulting curve was obtained to be r=0.75. Genotypes 4 and 18 with a similarity coefficient of 0.91% demonstrated the highest similarity while genotypes 21 and 15 with a similarity coefficient of 0.63% showed the lowest similarity. Of the primers in use, the OPB-18 primer produced 12 bands (the highest number of bands) and the OPA-09 primer produced 5 bands (the lowest number of bands). Cluster analysis also confirmed the results obtained from the profiles produced in the genetic differentiation of cultivars under study as well as the correlations resulting from the Jaccard similarity coefficient. Finally, genotypes were categorized into 13 groups based on the results and resulting dendrogram. Results of the cluster analysis performed using the Jaccard similarity coefficient revealed the genetic diversity among genotypes that emphasize on efficiency of selection in sugar beet genotypes.