The characteristics of fruit on an apple germplasm accession are examined at the National Clonal Germplasm Repository at Geneva, New York. Credit: U.S. Department of Agriculture, Northeast Regional Plant Introduction Station, Geneva, New York.

sions. Accession decisions are generally made following consultation with public and private sector representatives, crop advisory committees or technical advisory committees, and ARS officials.

The primary responsibilities of the repositories are to collect, identify, propagate, preserve, evaluate, document, and distribute clonal germplasm as part of the NPGS. This includes maintenance of an information file on each accession in the clonal collection (National Plant Germplasm Committee, 1986). For most material held in such collections, long-term storage is not feasible, so duplicate materials are generally maintained in field and greenhouse or screenhouse collections to provide some back-up protection against loss. The repositories are charged with developing active global collections of appropriate wild species and domestic cultivars, and to assemble a maximum level of genetic diversity possible for each genus and species for which they are responsible. They also conduct research to improve evaluation, propagation, characterization, and preservation of clonal germplasm (National Plant Germplasm Committee, 1986).

The national clonal germplasm repositories are intended to carry out the same function for vegetatively propagated crops as that carried out by the regional stations and the NSSL for seed crops. Unlike seeds held