Partial characterization of the P4 pathotype of pea seedborne mosaic virus

• Main Author: Kohnen, Paul D.
• Other Authors: Hampton, Richard O.
• Language: en_US
• Published: 2013
• Subjects: Peas > Diseases and pests; Mosaic diseases
• Online Access: http://hdl.handle.net/1957/36166

Biological, serological, and molecular characteristics of the P4 pathotype of pea seedborne mosaic potyvirus (PSbMV) were investigated. The characterization allowed P4 to be differentiated from other pathotypes of the same virus. P4 was distinguished from P1 on the basis of host symptomatology. It induced varied, but often distinctive symptoms in systemically-infected pea (Pisum sativum) cultivars. P4 inoculation of indicator hosts, notably Chenopodium album, resulted in the formation of local lesions. Pathotype P4 was seed transmitted at low frequencies relative to P1. In ten selected pea cultivars, seed transmission of P4 never exceeded 0.7%, while P1 was transmitted at frequencies as high as 33%. In mixed infections with P1, pathotype P4 was seed transmitted at 0- 2% as determined by P4-specific indirect ELISA. However, limited polymerase chain reaction (PCR) data suggest that P4 may be transmitted with P1 at higher rates than indicated by ELISA data. P4 was also aphid transmitted at relatively low rates. Pea aphids (Acyrthosiphon pisum) allowed 3 or 5 min acquisition access periods (AAP's) transmitted P4 at a maximum rate of 16% (3 aphids/plant). P4 transmission required short (1-7 min) AAP's and exhibited no bimodal character within tested parameters. P4 could be serologically distinguished from the other pathotypes using monoclonal and polyclonal antibodies. Tests with cross-reactive P4 antiserum suggest that P4 is more closely related to P2 than P1. P4-specific antiserum was derived by cross-absorbing diluted antiserum with P1- infected pea sap to eliminate P1- reactive antibodies. P1 and P4 RNA was detected and differentiated using pathotype-specific oligonucleotide primers in conjunction with PCR. Viral RNA sequences were amplified in pure preparations as well as crude pea tissue (leaf, root, pollen, and seed) extracts. === Graduation date: 1993