Submitted to: Soybean Research World Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 5, 2004
Publication Date: February 5, 2004
Citation: Mengistu, A., Ray, J.D. 2004. Use of molecular techniques to differentiate the diaporthe/phompsis complex [abstract]. VII World Soybean Research Conference. p. 69. Technical Abstract: The Diaporthe/ Phomopsis complex comprises at least four distinct fungi, all of which cause important diseases in soybean: Diaporthe phaseolorum var sojae, var caulivora, var meriodinales and Phomopsis longicolla. The taxonomy of this species and varieties is complex and has been difficult and controversial mainly because of considerable variation for morphological characters, growth and pathogenicity. Cultures representing the four groups of Diaporthe/Phomopsis were collected from three states in the northern and three states in the southern USA. Three to five cultures were obtained from each state. Isolates were characterized morphologically to determine the cultural characteristics. Pure isolates were grown in broth culture for two weeks, filtered, freeze dried and ground to a fine powder. DNA was isolated using specialized fungi kits. Molecular markers were developed from preliminary RAPD screening that could differentiate among the four distinct fungi. The application of these markers to a wide range of isolates as well as other molecular identification techniques is presented.