Campus Units

Plant Pathology and Microbiology, Agronomy

Document Type

Article

Publication Version

Published Version

Publication Date

9-2006

Journal or Book Title

Plant Disease

Volume

90

Issue

9

First Page

1186

Last Page

1194

DOI

10.1094/PD-90-1186

Abstract

Greenhouse, growth chamber, and field experiments were conducted to develop a method to assess resistance of soybeans to Cadophora gregata (Phialophora gregata), causal agent of brown stem rot (BSR). In the new method, C. gregata is introduced at the base of the stems of 2-week-old soybeans, and the presence of the fungus is assessed in the tips of the stems 5 weeks later. To test the effectiveness of the method, two populations of soybeans and 10 checks were inoculated at the stem base and then assayed for fungal colonization of the stem tips, percentage of symptomatic leaflets, and percent internal stem length discolored. The lines also were planted in naturally infested fields to assess for percent internal stem length discolored, and were tested for the presence/absence of a BSR-resistant molecular marker. Greenhouse, field, and molecular marker data were compared. Linear regression analysis suggested that percentage of plants with colonized stem tips explained 41 to 64% of the variability (P < 0.0001) in percent stem length discolored in the field and 58 to 85% of the variability (P < 0.0001) in molecular marker data for BSR resistance. Percent stem length discolored assessed in the greenhouse had the lowest correlation with percent stem length discolored in the field and with the molecular marker. Of three incubation temperatures tested, 22°C was the most conducive for distinguishing resistant/susceptible soybeans using the colonization method.

Comments

This article is published as Tabor, G. M., S. R. Cianzio, G. L. Tylka, R. Roorda, and C. R. Bronson. "A new greenhouse method to assay soybean resistance to brown stem rot." Plant disease 90, no. 9 (2006): 1186-1194, doi; 10.1094/PD-90-1186. Posted with permission.

Copyright Owner

The American Phytopathological Society

Language

en

File Format

application/pdf

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