Evaluation of soybean resistance toPhialophora gregataculture filtrate in tissue culture

✍ Scribed by D. B. Willmot; C. D. Nickell; J. M. Widholm; L. E. Gray

• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 540 KB
• Volume: 77
• Category: Article
• ISSN: 0040-5752
• DOI: 10.1007/bf00266191

✦ Synopsis

Resistance to the fungal pathogen, Phialophora gregata (Allington and Chamberlain) W. Gams, the cause of brown stem rot (BSR) in soybean [Glycine max (L.) Merr.], is an important trait for cultivars grown in the northern USA. A novel tissue culture method was developed where ten soybean cultivars were differentiated on the ability of their excised cotyledons to remain green and initiate callus in a tissue culture medium containing P. gregata culture filtrate. Cultivar BSR classifications by the cotyledon method corresponded to greenhouse root-dip assay classifications in 80%, 100%, and 90% of the three P. gregata isolate treatments. Another method, employing pieces of somatic callus exposed to the culture filtrate, had a 70% average correspondence to the greenhouse results. Physiologic specialization was demonstrated in parallel in vivo/in vitro assays for the first time. These data suggest that the cotyledon method would accurately identify soybean lines resistant to certain aberrant or wild-type P. gregata isolates.