GENETIC-VARIATION WITHIN AND BETWEEN 2 CULTIVARS OF RED-CLOVER (TRIFOLIUM-PRATENSE L) - COMPARISONS OF MORPHOLOGICAL, ISOZYME, AND RAPD MARKERS

Morphological, isozyme and random amplified polymorphic DNA (RAPD) mar kers were used to estimate genetic variation within and between cultiv ars of red clover (Trifolium pratense L.), an important temperate fora ge legume. Two cultivars of red clover, Essi from Europe and Ottawa fr om Canada, were evaluated. Six monogenic morphological characters were observed for 80 plants from each of these two cultivars. All six morp hological loci were polymorphic in the cultivar Essi whereas only four loci were polymorphic in the cultivar Ottawa. Forty plants from each cultivar were assayed for isozyme markers. A total of 21 enzyme-coding loci with 43 alleles was detected using twelve enzyme systems. Thirte en and nine of these loci were polymorphic in Essi and Ottawa, respect ively. The mean number of alleles per locus was 1.81 in Essi and 1.67 in Ottawa. Seventeen random 10-mer primers were screened for RAPD mark ers. Nine primers which gave clear and consistent amplified products w ere used to assay 20 individuals from each cultivar. Each primer gave from 7 to 20 amplified bands with an average of 14.8 bands per primer. One hundred and eight of 116 putative loci were polymorphic in Essi a nd 90 of 98 loci were polymorphic in Ottawa. High within-cultivar vari ation was observed in both cultivars using both isozyme and RAPD marke rs. This high polymorphism makes these markers useful for germplasm ch aracterization and genetic studies in red clover.