METHODOLOGICAL STUDY OF GENETIC-RESOURCES CONSERVATION OF PERENNIAL RYEGRASS BY POOLING WILD POPULATIONS

From 547 natural populations of perennial ryegrass previously studied for agronomic characteristics, 42 populations were chosen and regroupe d in order to create 9 breeding or pool populations representative of the observed diversity. Agronomic and ecogeographic criteria were take n into account and multivariate analyses were used. This method of poo l creation is presented as a pre-breeding process allowing the conserv ation of diversity and the preparation of genetically original materia l which can be used directly in breeding programmes. The criteria used in creating the pool populations are discussed and justified with the help of discriminant analyses and isozyme studies. Finally, further e xperimental studies needed in order to verify the relevance of these g roupings are proposed.