Tracking soybean mosaic virus movement in soybean by leaf imprint immunoassay

The responses of soybean (Glycine max (L.) Merr.) to soybean mosaic virus (SMV) include mosaic, necrosis and no symptoms, and vary with virus strain and allele of the gene for resistance (Rsv) carried by the host. Genetic studies have shown that plants giving mosaic are susceptible, and that plants giving either the necrotic or symptomless response are resistant. The objective of this study was to examine the mechanism of resistance by tracking SMV replication and movement in susceptible responses, and its restriction in necrotic and symptomless responses. Two SMV strains were inoculated at a single spot to Rsv-containing genotypes, selected to give each response. The leaf imprint immunoassay was developed and used to track the rate and extent of invasion by SMV from the tip of a primary, unifoliolate leaf to regions within that leaf and to the stem and younger trifoliolate leaves. In susceptible responses, SMV was detected at the site of inoculation in 6-7 days, and throughout the mid-rib and in the first trifoliate leaf in 8-9 days. In necrotic resistance responses, SMV was detected at and around the inoculation site in 8-9 days and in leaf veins, midrib and the first trifoliolate in 15-17 days, but was restricted to necrotic areas. In symptomless resistance responses, no virus was detected at any time. Greater virus replication and movement was found in unifoliolate and trifoliolate leaves of younger (15 days-old) than of older (18-days-old) plants. It was concluded that: (i) necrotic ally-responding cultivars manifest resistance by reduction and delay in replication, and by restriction of virus movement; (ii) virus replication is restricted in resistant cultivars; and (iii) rate and extent virus replication and movement is affected by stage of plant development.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Plant Pathology, Physiology, and Weed Science

Department dc:contributor.department

Plant Pathology, Physiology, and Weed Science

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1994

Author dc:creator

• Gera, Tarun

Chair dc:contributor.committeechair

• Tolin, Sue A.

Committee members dc:contributor.committeemember

• Warren, Herman L.
• Buss, Glenn R.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-12232009-020606

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/46408