190 • Technologies To Maintain Biological Diversity 



more consistent information to users (117). De- 

 velopment of uniform crop descriptors that in- 

 clude information about the storage history of 

 an accession as well as data on the original 

 collector, collection site, vegetative and repro- 

 ductive characteristics, disease or pest suscep- 

 tibility, and biochemical characteristics (e.g., 

 isoenzyme profiles) is important for consistent 

 and accurate information (7,98,117). This task 

 for NPGS has been assigned to crop advisory 

 committees (see ch. 9). 



Several data storage and retrieval methods 

 are now used (65). A collection of only a few 

 hundred accessions might use file cards or 

 books. As the collection grows, a computer- 

 based system may be more appropriate. Large 

 collections, such as the Royal Botanic Gardens 

 in England, have developed systems adapted 

 to their specific needs (97). The nature of the 

 data in computer-based information manage- 

 ment systems depends on whether the materi- 

 als being stored are agricultural crops (1,125) 

 or wild species (34,97). 



The Germplasm Resources Information Net- 

 work (GRIN) of NPGS is an example of a large 

 information system designed to coordinate data 

 from multiple collections in the United States. 

 GRIN, once fully established, is expected to pro- 

 vide information on all accessions held by 

 NPGS. Although the capacity of the system is 

 more than adequate, entering information is, 

 after several years, still in the preliminary stages. 

 OTA has found GRIN praised by managers of 

 NPGS facilities for its recordkeeping operations 

 but criticized by potential users because de- 

 tailed information is unavailable on individual « 

 accessions and obtaining results of searches can | 

 take considerable time. GRIN at present does 

 not collect information on privately held col- 

 lections of agricultural plants, such as those co- 

 ordinated by the Seed Savers Exchange or the 

 North American Fruit Explorers, nor does it 

 hold information on wild species. 



USING PLANTS STORED OFFSITE 



Collections are used for crop development 

 as well as conservation. Plant breeders and sci- 

 entists who may depend on the genetic diver- 

 sity in such collections require specific infor- 

 mation about accessions to select appropriate 

 plants. Genes in selected accessions are incor- 

 porated into improved crop varieties using 

 traditional plant breeding practices. In addi- 

 tion, biotechnology may provide methods that 

 could enable development of improved crop va- 

 rieties or more efficient use of genes in plants. 



Evaluation 



Evaluation of plant germplasm involves the 

 examination of accessions for the presence and 

 quality of particular traits that may be of use 

 to crop breeders. 



In general, evaluation examines traits that 

 may be genetically quantitative (i.e., controlled 

 by many genes) and subject to environmental 

 influence, such as drought tolerance or earli- 



ness of maturity in a fruiting crop. This assess- 

 ment can be complicated in a genetically vari- 

 able accession because all individuals may not 

 express the trait equally (81). Further, changes 

 in conditions (e.g., appearance of a new dis- 

 ease) can require further evaluation for new 

 traits. In addition, new accessions must be 

 evaluated. Thus, evaluation may be considered 

 a never-ending task (81). 



Evaluations vary according to the species or 

 trait being examined and may be both lengthy 

 and complex (37). A test for yield potential, for 

 example, would require different growing con- 

 ditions than a test for genes that enable plants 

 to grow in acid soils. And sufficient space to 

 grow plants to maturity is needed, along with 

 trained personnel to design the tests and to ana- 

 lyze results (81). The time required too can be 

 considerable. Testing the wheat held by the U.S. 

 National Small Grains Collection for resistance 

 to stem and leaf rust, for example, is expected 

 to require more than 10 years (96). Evaluation 



