2185506 ITS-RFLP internal transcribed spacer-restriction fragment length polymorphism 14 2185508 ITS-RFLP ITS-restriction fragment length polymorphism 2 2185507 ITS-RFLP intergenic spacer-restriction fragment length polymorphism 1 2185509 ITS-RFLP ITS amplicon analysis after restriction enzyme digestion DdeI 1