Abstract

The weeds Amaranthus viridis and Trionthema decandra harboured the amaran- thus mosaic virus and the virus was transmitted by the aphids Aphis gossypii. A. crac civora and Myzus porsicae. From the physical properties, host range and serological tests, these two virus isolates were identifiod as strains of amaranthus mosaic virus. The weeds Solunun nigrum and T. portulacastrum harboured the chilli mosaic virus and the aphids A. gossypii, A. evonymii. A. craccivora and M. persicae were able to transmit the virus. These two virus isolates were identified as strains of potato virus Y. The present study indicated the possibility of the weeds serving as vital links in the disease cycle.

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