Alfalfa Mosaic Virus. In: Compendium of Pea Diseases and Pests

Authors: LARSEN, RICHARD - Washington State University; Porter, Lyndon

Submitted to: American Phytopathological Society Press
Publication Type: Book / Chapter
Publication Acceptance Date: 7/17/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Alfalfa mosaic virus (AMV) is one of the most geographically widespread viruses in the world. It has a natural and experimental host range of approximately 697 plant species. AMV was first described in the US in 1933 and is commonly found througout the Western US. AMV-infected peas are stunted when infection takes place early and foliage exhibits a general chlorosis and purple or brown necrotic streaks in the vascular system along the stems and leaves. Pods are often misshapen, chlorotic, or discolored and often exhibit brown necrotic lesions. Seed sizes are reduced impacting yield. Alfalfa is the most common perennial host of AMV. Pea fields near alfalfa fields are at risk for infection by AMV. AMV is transmitted in a nonpersistent manner by a least 20 aphid species. The pea aphid and green peach aphid are the most important vectors of the virus. The virus has not been shown to be seed-transmitted in pea. Pea lines with tolerance to AMV have been identified, but no lines or commercial cultivars have been shown to have complete resistance. To manage AMV, do not plant pea fields near alfalfa fields. Insecticides have not been effective in preventing infection but they may help to reduce secondary spread of viruliferous aphids. Transgenic peas containing the coat protein of AMV have been shown to improve partial resistance to AMV.

Technical Abstract: Alfalfa mosaic virus (AMV) is one of the most geographically widespread viruses in the world. It has a natural and experimental host range of approximately 697 plant species. AMV was first described in the US in 1933 and is commonly found througout the Western US. AMV-infected peas are stunted when infection takes place early and foliage exhibits a general chlorosis and purple or brown necrotic streaks in the vascular system along the stems and leaves. Pods are often misshapen, chlorotic, or discolored and often exhibit brown necrotic lesions. Seed sizes are reduced impacting yield. Alfalfa is the most common perennial host of AMV. Pea fields near alfalfa fields are at risk for infection by AMV. AMV is transmitted in a nonpersistent manner by a least 20 aphid species. The pea aphid and green peach aphid are the most important vectors of the virus. The virus has not been shown to be seed-transmitted in pea. Pea lines with tolerance to AMV have been identified, but no lines or commercial cultivars have been shown to have complete resistance. To manage AMV, do not plant pea fields near alfalfa fields. Insecticides have not been effective in preventing infection but they may help to reduce secondary spread of viruliferous aphids. Transgenic peas containing the coat protein of AMV have been shown to improve partial resistance to AMV.