DYNAMIC MANAGEMENT OF GENETIC-RESOURCES - 1ST GENERATION ANALYSIS OF SUNFLOWER ARTIFICIAL POPULATIONS

Twenty-two artificial populations composed of wild, interspecific and cultivated Helianthus genotypes were constructed in southern Europe. T he long-term objective was to develop a methodology for dynamic manage ment of sunflower genetic resources. Eight parental populations of 75 individuals each were analysed for agromorphological traits. The genet ic variability was very large. The wild and interspecific genotypes we re clearly differentiated from the cultivated ones. The first generati on of offspring was analysed by isozyme characterisation (5 alleles) a nd restriction fragment length polymorphism (RFLP) (using a ribosomal gene spacer probe discriminating several parental genotypes). Differen ces in frequencies of isozyme alleles between parental and offspring s amples were consistent with the existence of intercrosses between wild , interspecific and cultivated genotypes. Half the RFLP patterns in th e offspring generations were similar to parental patterns and the othe r half were new combinations of parental haplotypes. These patterns co uld have resulted from intercrosses. Although genetic variability in t he artificial populations may decrease over time, new genotypes can be generated through intercrosses and will contribute to enlarge sunflow er genetic resources.