Purified rice dwarf phytoreovirus preparations, after rehydration foll
owing drying without freezing (L-drying) and sucrose density gradient
centrifugation, sedimented to the same position as untreated controls.
Upon storage at 65 degrees C, virion conformation in L-dried preparat
ions supplemented with 1% sucrose was maintained better than without a
dditives. Moreover, during storage for 6 years at -70 degrees C, infec
tivity of L-dried preparations from crude extracts of infected rice pl
ants containing 5% sucrose was higher than controls based on the numbe
r of count of infected foci on cell monolayers and transmission to ric
e seedlings by leafhopper of the vector Nephotettix cincticeps, which
had been injected with such extracts.