Fingerprinting of Ustilago Scitaminea (Sydow) in Egypt Using Differential Display Technique: Chitinase Gene the Main Marker

The sugarcane smut disease caused by Ustillago scitaminae causes the greatest yield losses and is the most difficult to control through producing host genetic resistance, in part because the pathogen occasionally produces a new race that overcomes prior host resistance. In the smut fungi, few features are available for use as taxonomic criteria (spore size, shape, morphology, germination type, and host range). DNA-based molecular techniques are useful in expanding the traits considered in determining relationships among these fungi. Approximately 17 smut infected samples from five different sugarcane cultivars were collected from different governorates in Upper Egypt. Only 12 fungal isolates were succeeded to grow on Potato Dextrose Agar (PDA), the mycelium of each isolate was subjected to RNA extraction, followed by differential display technique to classify these isolates. Determination of the identity of sugarcane smut races and maintenance of resistant commercial varieties has proven to be difficult. So, it is essential to know the fungus race to find the suitable tools for controlling. For that reasons this study focusing on the scanning of the fungal mRNA, especially the one of the functional genes like chitinase gene. This study concluded that chitinase genes are the most suitable for genotyping study between fungal isolates. Differential display had the capability to demonstrate the changes carried out in fungal genome and could be a good substitute to the DNA sequence for fingerprinting of Ustillago sp., because of it is so easy, achieved in no time, cheep and impressive.