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

3 Abstract: The sugarcane smut d isease caused by Ustillago scitaminae causes the greatest yield losses and is the most difficult to cont rol through producing host genetic resi stance, in par t because t he pathogen occasionally produces a new race that overcomes pri or host resistance. In t he smut fungi, few f eatures are available f or us e as taxonomic cri teria (s pore s ize, shape, morphology, germination t ype, and host range). DNA-based molecular techniques are useful in expanding the traits considered in determining relationships among t hese fungi. Approximately 17 smut infected samples f rom five d ifferent sugarcane cultivars were collected from di fferent governorates in Upper Egypt. Only 12 fungal isolates were succeeded to g row 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 a nd maintenance of re sistant co mmercial va rieties has p roven to be difficult. So, i t i s e ssential to know t he f ungus race to find the sui table tools fo r controlling. For t hat 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 gen es are the most suitable f or genotyping study between fungal is olates. 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 fing erprinting of Ustillago sp., because of i t i s so easy, achieved in no time, ch eep and impressive.