Identification of Causal Agent of Rice Stem Rot (Magnaporthe salvinii) in Fars Province

Stem rot disease caused by Magnaporthe salvinii is one of the most common limiting factors for rice production. It was first reported from Italy and in a short time from all over the world. Although rice stem rot in tillering stage was identified widely in different area of Fars province, no causal agents had been detected before the study. The aim of this study was to evaluate the causal agent of rice foot rot specially Magnaporthe salvinii in Fars province. During 2008-2009, foot and root rotted rice samples were collected from infected fields in Fars province. After purification of the Samples and their cultivation in selective media, the produced fungal sexual forms were characterized. In the next step, all of the isolates were tested for pathogenicity. The cultured isolates first produced white colonies in culture media, but their color changed to gray after few days. Based on our results, the asexual and sexual forms were diagnosed as Nakataea sigmoidea and Magnaporthe salvinii, respectively. Pathogenicity tests showed that the isolate is very virulent and It can make injuries in the susceptible hosts. The result obtained from this study showed that rice foot and root rot caused by Magnaporthe salvinii is very dispersed in various aria of Fars province. This is the first report of Magnaporthe salvinii in Fars province.