The roles of guttation fluid, irrigation water, contact
between plants and transplantation into contaminated soil in the transmission
of Rice yellow mottle virus (RYMV) were assessed. RYMV presence
and infectivity were tested by Enzyme-Linked Immunosorbent Assay (ELISA)
and by inoculation to susceptible rice cultivar BG90-2. The virus was
readily detected in guttation fluid collected from infected rice plants.
Transmission tests from this fluid led to high disease incidence (86.6%).
Irrigation water collected at the base of infected plants growing in pots
was less infectious, as inoculations led to disease incidences below 40%.
No virus was detected and could be transmitted from field-irrigation water.
Up to 44% healthy rice plants whose leaves were in contact with those
of infected plants became infected but, no transmission occurred through
intertwined roots. Transplantation of rice seedling into virus-contaminated
soil also led to plant infection. However, virus survival in the soil
decrease rapidly and infectivity was completely lost 14 days after soil
contamination. Altogether, these results indicated that high planting
densities of rice are likely to favour secondary spread of rice yellow
mottle disease. Transplantation of rice seedlings not earlier than 2 weeks
after soil preparation should prevent soil transmission of the virus.
Although guttation fluid is highly infectious its contribution to virus
infectivity in irrigation water is negligible as field-irrigation water
was not found to be an infectious source for RYMV.
M.D. Traore, V.S.E. Traore, A. Galzi-Pinel, D. Fargette, G. Konate, A.S. Traore and O. Traore, 2008. Abiotic Transmission of Rice yellow mottle virus Through Soil and Contact Between Plants. Pakistan Journal of Biological Sciences, 11: 900-904.