Genetic Diversity and Relationship of Some Sugar Beet Population and Their Correlation with Morpho-physiological Traits

The present study focuses on the identification of variation in genetic diversity in some of the breeding populations using yield, yield component, and root morpho-physiological traits in Beta vulgaris L. Eighty genotypes from 8 different sugar beet populations were used under a randomized complete block design with five replicates at the Azad University research field during the cropping season of 2021–2022. Significant statistical differences were recorded among the populations that indicate the genetic difference of the studied sugar beet population. Mean comparison of analyzed data revealed, P191 to displayed better traits in terms of sugar content, nitrogen content, pure sugar content, extraction coefficient, and root dry matter. Similarly, population M224 exhibited better root number, root yield, leaf weight, and sugar yield. The dendrogram using UPGMA revealed that the population formed three distinct clusters, with the greatest genetic distance between M249 and the 191 populations. This distance is expected to create maximum heterosis through crossbreeding between these two populations. The results indicate that the number of roots significantly affects RY, LY, Na, and WSY, but does not have a significant correlation with other traits. RY is correlated with LY, Na, and WSY, while LY is inversely correlated with WSC, ECS, and DM, and directly correlated with Na. Principal component analysis based on varimax rotation revealed that three factors explained the total variance to an extent of 87.6%: the first factor named WSC explained 54.5%, the second factor, called RY, accounted for 22.8%, and the third factor contributed to 10.2% of the total variance. The biplot from the first two components showed populations similar to cluster analysis grouping. The findings of this research provide valuable insights into the breeding and improvement of sugar beet populations.