Study of genetic diversity of Iranian indigenous turnip accessions (Brassica rapa L.) by morphological traits

As a plant from the family of Brassicaceae, turnip is of interest worldwide because of its food and medicinal properties. However, no study has been carried out for identifying and evaluating its genotypes in Iran yet. The current study was conducted for the evaluation of genetic diversity of 18 Iranian indigenous turnip accessions as well as one British cultivar, Top Millan, by 27 morphological traits under field conditions in Yazd Agriculture and Natural Resources Research Centre, Yazd, Iran in 2010. According to the analysis of variance, there were significant differences in most vegetative traits of the accessions. The results showed that the accession Chenaran had the highest storage root weight, big diameter and small diameter (186.6 g, 52.57 mm and 70.35 mm, respectively). The accession Esfahan had the highest leaf number (16 leaves) and the accession Tabas had the highest flower number (1672 flowers). The results of correlation analysis showed positive significant correlation between some important traits such as leaf size and storage root size and weight. In factor analysis, nine independent major factors explained 87.35% of total variance and cluster analysis grouped the accessions in seven groups. The genetic diversity of samples did not conform to their geographical distribution. In total, the results indicated that the studied genotypes had high diversity and are appropriate genetic resources for breeding programs.