Investigation of Genetic Diversity Among Different Oriental Tobacco (Nicotiana Tabacum L.) Varieties Using Multivariate Methods

Genetic diversity is the base of plant breeding. In present study 19 chemical and morphological traits in 36 genotypes were investigated with a 6×6 simple lattice design in Tirtash Education and Research Center. Results showed significant differences among genotypes for all studied traits. The highest and the lowest genotypic variation coefficient were related to percentage of sugar and nicotine، respectively. The highest and the lowest phenotypic variation coefficient were attributed to cured leaf yield and percentage of protein nitrogen، respectively. Broad sense heritability was the highest for percentage of total ash (92. 7) and the lowest for percentage of protein nitrogen (13. 9) and percentage of Phosphorus (22. 2). In factor analysis، six main and independent factors were identified; yield and related morphological characteristics (factor 1)، tobacco taste characteristics (factor 2)، nitrogen dependent characteristics (factor 3)، plant height (factor 4)، number of leaves (factor 5) and effective trait on tobacco leaf ripening (factor 6). These factors explained up to 80% of total variation among varieties. Cluster analysis based on Ward''s minimum variance classified genotypes into seven cluster s including 6، 5، 3، 8، 2، 4 and 8 genotypes، respectively.