Evaluation of genetic diversity in sugar beet (Beta vulgaris L.) genotypes using ISSR markers

Sugar beet is one of the most important plants playing a key role in human food production in the world. Sugar beet has nutritional value as rice, corn, wheat, potato and beans. The estimation of genetic diversity of plant material is the first step for identification, conservation of genetic resources and designing of breeding programs. In order to study the genetic diversity of 20 sugar beet genotypes, 20 ISSR primers were used. After DNA extraction and PCR amplification, using ISSR primers the scores (0 and 1 for absent and present band, respectively) of resulting bands subjected to statistical analyses. Genetic diversity indices of ISSR markers in the studied sugar beet genotypes showed that UBC853 and UBC847 had the highest (0.38) and lowest (0.13) values of polymorphism information content respectively. Also UBC830 locus had the highest rate (4.32) of Shannon diversity index, which represents the genetic diversity among populations, whereas UBC847 had the lowest (0.58) Shannon index. Cluster analysis based on molecular data using Jaccard's similarity coefficient and UPGMA method, classified the sugar beet genotypes into four major groups. Based on the results of principal components analysis, the first three principal components explained 72.67, 5.99 and 4.05 percent of total (82.72%) total variation indicating ISSR markers have good distribution in the whole genome. The classification of the sugar beet genotypes based on the first principal components, had similarities and differences with cluster analysis. Results of this study can be used in breeding programs of sugar beet.