Alfalfa mosaic Alfamovirus (AMV) was widely distributed in Sultanate of Oman as 88% of the fields surveyed were found to be infected. The virus was identified on the basis of biological, serological and some physical properties, and was recorded on 21 hosts comprising of 4 field crops, 14 vegetables, 1 ornamental plant and 2 weed species; distributed in 9 botanical families. Two new hosts of AMV i.e. Heliotrope (Heliotropium europaeum) and Ammi (Ammi majus) were found. The virus was detected in all parts of systemically infected plants except wood. Seed transmission in the farmers' samples, commercial stock and seeds harvested from mechanically inoculated plants was 2 to 8%, 10.2% and 26%, respectively. The virus isolate had a dilution end point 1 x 10- 3 - 10-4, longevity in vitro for 3 days at 25°C and thermal inactivation point of 65-67°C. Cotton aphids (Aphis gossypi/) transmitted the virus in a non-persistent manner. Wide occurrence and distribution of AMV in the country is attributed to its broad host range, seed-transmission, adaptation to high temperature and abundance of insect vector.

Alfalfa mosaic Alfamovirus (AMV) was widely distributed in Sultanate of Oman as 88% of the fields surveyed were found to be infected. The virus was identified on the basis of biological, serological and some physical properties, and was recorded on 21 hosts comprising of 4 field crops, 14 vegetables...