Characterization of chromosomal DNA and DNA polymorphism in Korean cultivars ofAllium sativum L.

The genetic background of the garlic (Allium sativum L.) is not well understood, since it is cultivated exclusively by vegetative propagation. To understand its genetic background, a local cultivar, Danyang, was chosen, and several basic characteristics of its chromosomal DNA were examined. Its G + C content was 40.6%, and the relative proportion of fast reassociated sequences, intermediate reassociated sequences, and slow reassociated sequences were 12%, 40%, and 48%, respectively. The genome size, calculated based on reassociation kinetic experiments, was 1.11 x 10¹⁰ bp or 12.16 pg per haploid genome. To compare the genetic variation among four local cultivars, Munkyung, Seosan, Euiseong, and Danyang, random amplified polymorphic DNA (RAPD) analysis was performed. By using slightly longer primers, 18–24 nucleotides in size, than the traditional primers used for such analysis, more reliable RAPD results were obtained. 15 primers gave rise to amplified bands, and the results could be grouped into two categories. The patterns of amplified products produced by 12 primers, group A, were polymorphic. These results were analyzed using a NTSYS-PC (Numerical Taxonomy and Multivariate Analysis System), and a dendrogram grouping the four local cultivars was produced. The three primers of group B gave rise to a monomorphic band pattern from four local garlic clutivars, indicating that these primers possibly recognize garlic specific sequences. These primers were useful in identifying genetic variations among theAllium species.