Race Identification and Biological Control of Ustilago Scitaminea the Causal
Organism of Sugarcane Smut Disease in Upper Egypt.

• Abd- Elrasoul ,M.M.A.,(1) F.G. Fahmy.(2), Higgy, A.H.(3), And Abd- Elrazik,A.A.(4)
• (1,3) Nag-hammadi Sugar Company Research Station, Sugar and Integrated Industries Company, Egypt..
• ( 2,4 )Plant Pathology Department , Faculty of Agriculture , University of Assiut, Egypt.
• The Third International Conference onIPM Role in Integrated Crop management and Impacts on Environment and Agricultural Products. 26-29 November 2005, Giza, Egypt.

Abstract

Four isolates of Ustilago scitaminea Syd, the causal organism of sugarcane smut disease were obtained from diseased samples showing symptoms of smut and collected from different localities of El-Minia, Qena and Aswan Governorates. These isolates were able to infect NCo310 sugarcane variety (highly susceptible) with variable degrees of infection. Two of these isolates were highly pathogenic; one isolate was moderate, while other isolate had no effect. The enzymatic patterns of esterase and phosphatase in addition to the proteolytic enzymes protein were used to determine the genetic variability among the four tested isolates of Ustilago scitaminea. The results of the dimeric esterase zymogram for the four tested isolates revealed that esterase was controlled by two loci, Est-1 and Est-2. The locus of Est-1 was dimeric and represented by two alleles, one was fast (Est-1F) and one slow (Est-1s) allele. The four isolates were heterozygous at the Est-1 locus in which three bands were detected. The acid phosphatase pattern showed no differences between the four isolates of Ustilago scitaminea. However, all of tested isolates exhibited only one band at RF= 0.45 in their zymogram. The electrophoretic pattern of enzymatic protein revealed 6 enzymatic bands at RF 0.6, 0.73,077,0.80,0.84 and 0.96. No differences were observed among the four isolates of Ustilago scitaminea in the enzymatic protein pattern. Testing antagonistic capability of Trichoderma spp. against Ustilago scitaminea in vitro, revealed that Trichoderma viride had a mycoparasitic effect on the growth of smut disease pathogen. Biological control of the smut disease by dipping healthy cane setts in T. viride suspension ( 2 x 106 propagules / ml) before and after inoculation with the pathogen gave a noticeable control of the disease. The efficiency of Saccharomyces cervisiae in bio-control of the smut disease of sugarcane was also studied under greenhouse condition. Results indicated that using S. cervisiae as a bio-agent agent was effective in controlling the disease. A complete control of the disease was achieved by spraying cane plants with the tested yeast at the same time of the pathogen addition.