بررسي تنوع جمعيت هاي قارچ عامل سوختگي غلاف برنج در مزارع مناطق شمالي ايران

To determine possible heterogeneity among populations of Rhizoctonia solani AG 1-IA inciting sheath blight of rice in north of lran, 2 16 samples of infected rice sheaths,leaves and panicles were collected from different area of Guilan ,Golestan and Mazandaran provinces in 2000 and 2001. Two hundred and sixteen isolates of R. solani recovered from the diseased sheaths were compared by gel electrophoresis of soluble proteins and thin layer chromatography (TLC) of sclerotial lipids. The isolates were classified into 16 groups based on their protein patterns in SDS-PAGE. The reference strain of R. solani AG 1-IA was grouped with the second largest group of the isolates prevalent in the three provinces. Total lipids were extracted from the sclerotia separated by one-dimensional TLC and stained with molybdophosphoric acid. The isolates were differentiated into 38 groups on the basis of their lipid profiles. The reference strain of AG I-IA clustered with the fifth largest group of the isolates.No close correlation existed between the two criteria (markers) in separating the isolates into specific groups.It appears that a heterogenous assemblage of isolats of R. solani AG I -IA exists in the rice growing areas of north of Iran.