Australian National University, Canberra, Australia

Background and objectives
The origins and goals of ICTVdB in DELTA format, its decimal code, character list and structure on the World Wide Web have been described earlier [1]. The ICTVdB is congruent with ICTV Reports with respect to virus description, but has active links to other relevant databases (genome, hosts and symptoms, etc.). It thus complements, rather than competes with, the ICTV Reports. Plant viruses comprise a discrete subset, some 15-20% of all viruses, and although many are not known in great detail, they represent the most completely described section of ICTVdB.

The structure of ICTVdB facilitates continuous updating through peer review (by ICTV Study Groups), and provides a vehicle for communicating information on viruses at all levels via the Web. This report seeks to engage the attention of plant virologists, with a view to updating this section of ICTVdB. In addition it will demonstrate an interactive key for facilitating virus identification in research, teaching and agricultural applications.

Materials and methods
The successful development of the plant virus database has depended on the willingness of individual plant virologists to contribute their expertise through completion of lengthy hard-copy questionnaires. The larger task of completing ICTVdB depends on a similar collaborative effort, but will be facilitated by electronic data input and management on the Web [2]. Contributors will follow prompts displayed by EntVir (enter virus; http://life.anu.edu.au/viruses/EntVir/submit.htm), adding data to update the description of a virus. The existing natural language description, with images and links to other databases, can be consulted in the process of data submission. Inputs will then be reviewed in two steps: by ICTVdB management to check for errors, and by ICTV Study Groups for formal approval. Management will generate a natural language translation of the description from data submitted, and this will be returned to the contributor for checking, and forwarded to the Study Groups for review. The submission process, which is being refined to provide access at different taxonomic levels and for different classes of data, will be demonstrated.

Results and conclusions
Intkey, an interactive key for identification and data retrieval from DELTA databases, uses a data matrix generated from ICTVdB, and offers more comprehensive features than other programs [2]. These include entry and deletion of attributes in any order, calculation of the 'best' characters for use in identification, the ability to allow for errors (whether made by the user or in the data, or due to lack of data), and the ability to express variability or uncertainty in attributes. Application of the Intkey data matrix (now available on the Web; http://biodivesrity.uno.edu/delta) to identify plant viruses, will be demonstrated.

1. Buechen-Osmond C, Dallwitz MJ, 1996. Archives of Virology 141, 392-399.
2. Buechen-Osmond C, 1997. Archives of Virology 142, 1734-1739.