Germplasm Reserves of North American Nut Trees

Abstract

Existing germplasm collections of the different nut tree species are correlated with the amount of research and the commercial value of the nut crop. There is a need to delineate specific objectives of germplasm collections for each species followed by commitments on a long term basis. A national committee would be of benefit in achieving the desired results. Nut tree species, of Carya, Castanea, Corylus, Juglans, and Pistaciaare discussed. All the species are highly heterozygous. Germplasm reserves should be maintained in clonal collections: Seedling material, with the exception of black walnut, is of secondary importance. Genetic vulnerability is a serious threat only for those species where commercial production is limited to one or a few clones. Yet, valuable germplasm may be lost forever if greater effort is not given to its preservation.