Investigation on the genetic structure of Gnomonia leptostyla populations by PCR-RFLP in Azarbayejan-e-Sharqi, Iran

Gnomonia leptostyla (Fr.) Ces. et de Not., the teleomorph of Marssonina juglandis (Lib.) Magn., is the causal agent of the walnut anthracnose, a wide spread disease in almost all the walnut growing areas and causes severe damages particularly in the north of iran such as Kermanshah, Azarbayejan, Khorasan and Karaj regions. Sampling was conducted from several areas of Azarbayejan-e-Sharqi province during 005-006. 60 Fungus isolates were isolated from samples and cultured as streaked single spore on OMA. Molecular techniques based on PCR-RFLP applied to investigate the genetic variability of G. leptostyla.Total DNA was isolated from mycelial powder by rapid mini-preparation method. A region of 60 isolates coding for the small-subunit ribosomal RNA (SrDNA-8s) and the internal transcribed spacer (ITS) were amplified and analyzed by restriction enzyme digestion. The results of PCR-RFLP showed no polymorphism either in length or in pattern among all the isolates tested.