|Carpenter, Louise - STA LABORATORIES|
Submitted to: Acta Horticulture Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 3, 2004
Publication Date: November 1, 2005
Citation: Ling, K., Carpenter, L. 2005. Pepino mosaci virus, an emerging disease in greenhouse tomato production worldwide: is seed responsible?. Acta Horticulturae. (ISHS) 695:43-50. Technical Abstract: Pepino mosaic virus (PepMV), a potexvirus, was first described in 1980 from pepino (Solanum muricatum) in Peru. In 1999, it was identified for the first time in greenhouse-grown tomatoes in Europe. Subsequently, the virus was reported in North America. PepMV is becoming a serious threat to greenhouse grown tomatoes because the virus is easily spread by mechanical means and greenhouse tomato production provides ample opportunities for disease spread through cultivation and worker handling. The origin of virus sources in greenhouses, however, was still unknown though potexviruses are not considered seedborne, seed was suspected in these cases. Research experiments were undertaken to determine if PepMV, tomato strain, can be seedborne and transmitted from seed derived from PepMV-infected plants. Routine seed health assays of seed samples, using biological, serological, and molecular methods for PepMV have produced positive results, suggesting that PepMV may be seedborne. However, a growout of over 5,000 tomato seedlings from a seed lot that consistently tested positive for PepMV by enzyme-linked immunosorbent assay (ELISA) and bioassay did not result any virus transmission. Further evaluation of germinating seeds from this lot, showed that PepMV was not present in the embryo, but instead concentrated in the seed coat. These results indicate that PepMV may be seedborne, but not easily transmitted to germinating tomato seedlings from virus-infested tomato seeds. More research is needed to confirm these results and determine the affect of the virus location on transmission of the virus. The possible implication of these findings on seed health assays is discussed.