Biological and molecular variability of zucchini yellow mosaic virus on the island of Martinique

Zucchini yellow mosaic potyvirus (ZYMV) was isolated from zucchini squash on the island of Martinique for the first time in 1992, and it is now widespread on the island. Fourteen isolates collected from different cucurbit crops in 1992 and 1993 exhibited biological and antigenic variability as revealed by using differential hosts and a series of monoclonal antibodies. A partial sequencing of the coat protein and putative polymerase coding regions of the 14 isolates revealed that there was also some molecular variability, lower within the group of Martinique isolates than with ZYMV isolates from other geographical origins. This variability can result either from the introduction to the island of different ZYMV strains, or from a rapid evolution of an introduced ZYMV population with a narrow genetic base. The incidence of the observed variability will affect the development of efficient and durable control strategies.