Races of Phytophthora sojae in Iran.

Phytophthora root and stem rot of soybean is a destructive disease of soybean in Iran. Races 1 and 3 of pathogen have already been reported from two major growing regions of the crop, Lorestan and Golestan provinces. In a survey during 2004-2005, 142 isolates of P.

PCR analysis of the Tri13 gene to determine the genetic potential of Fusarium graminearum isolates from Iran to produce nivalenol and deoxynivalenol.

Fusarium graminearum trichothecene producing isolates can be broadly divided into two chemotypes based on the production of the 8- ketotrichothecenes deoxynivalenol (DON) and nivalenol (NIV). Functional Tri13 gene required for the production of NIV and 4- acetyl NIV, whereas in the isolates producing DON and its acetylated derivates, this gene is nonfunctional. In this study, a total of 57 isolates from different fields of Mazandaran province, Iran were identified as F.