title: The genetic structure of tetraploid Avena: a comparison of isozyme and RAPD markers.
abstract: Isozymes were the first widely used molecular markers in plant population analysis. They yielded valuable information on the amount and the structure of genetic variability. DNA technology has provided new types of markers based on DNA sequence, which make it possible to study polymorphisms in a much greater proportion of the genome. This is the reason why the use of isozymes is less popular nowadays. This effect would be justified if all markers provided the same type of information on polymorphism and genetic relationships among populations; otherwise, it would be necessary to use different markers to obtain the complete picture of the genetic structure of populations and species. In this study, we compared data of isozyme and RAPD markers in the populations of two tetraploid species of wild oats: Avena barbata populations collected in Argentina, and Avena murphyi populations collected in Spain and Morocco. The samples were evaluated for 9 isozymatic systems and 10 primers. The structure of genetic variability was studied using Nei's method, and the relationships between populations were estimated using Hedrick and Jaccard's similarities for isozymes and RAPDs, respectively. As expected, RAPDs were more polymorphic than isozymes, but the information obtained from both markers was weakly correlated. The various reasons for this observation are discussed, but our conclusion is that in order to study the structure of genetic variability, several types of markers should be used.
authors.affiliation: Université Ibn Tofaïl, Faculté des Sciences, Département de Biologie; 14000, Kénitra, Morocco.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Benchacho
authors.forename: Rosana
authors.initials: R
authors.lastname: Guma
authors.forename: Marcelino
authors.initials: M
authors.lastname: Pérez De La Vega
authors.forename: Pedro
authors.initials: P
authors.lastname: García
mesh_terms: D001118:Argentina; D005819:Genetic Markers; D014644:Genetic Variation; D018745:Genome, Plant; D007527:Isoenzymes / Q000235:genetics*; D009018:Morocco; D010940:Plant Proteins / Q000235:genetics*; D006109:Poaceae / Q000201:enzymology / Q000235:genetics*; D011123:Polyploidy; D019105:Random Amplified Polymorphic DNA Technique; D013030:Spain
chemical_list: D005819:Genetic Markers; D007527:Isoenzymes; D010940:Plant Proteins