Host penetration and infection by the anastomosis groups of Rhizoctonia solani Kühn isolated from potatoes

The modes of penetration and infection of the isolates belonging various anastomosis groups (AG-2 type 1, AG-2 type 2, AG-3, AG-4 and AG-5) of Rhizoctonia solani Kühn isolated from potatoes were investigated on the underground stems of the host. | Tr. J. of Agriculture and Forestry 22 (1998) 609-613 © TÜBİTAK Host Penetration and Infection by the Anastomosis Groups of Rhizoctonia solani Kühn Isolated from Potatoes* Erkol DEMİRCİ Department of Plant Protection, Faculty of Agriculture, Atatürk University, Erzurum-TURKEY M. Timur DÖKEN Department of Plant Protection, Faculty of Agriculture, Adnan Menderes University, Aydın-TURKEY Received: Abstract: The modes of penetration and infection of the isolates belonging various anastomosis groups (AG-2 type 1, AG-2 type 2, AG-3, AG-4 and AG-5) of Rhizoctonia solani Kühn isolated from potatoes were investigated on the underground stems of the host. During the process of penetration, infection cushions were observed in all isolates in addition to the formation of lobate appressoria by AG-3, AG-5 and direct hyphal penetration of AG-4. Numerous fine infection pegs formed from infection cushions grew between or into epidermal cells following the penetration of cuticula. A similar mode of penetration was also occurred by the infection peg produced from every lobe of appressorium except that the infection peg enlarged immediately after passing through the cuticula. Further invasion of tissues beneath the epidermal layer continued inter- and intracellular manner. Patatesten İzole Edilen Rhizoctonia solani Kühn’nin Anastomosis Gruplarının Konukçuya Penetrasyonu ve Enfeksiyonu Özet: Rhizoctonia solani Kühn’nin patatesten izole edilen anastomosis gruplarına (AG-2 tip 1, AG-2 tip 2, AG-3, AG-4 ve AG-5) ait izolatların konukçunun gövdesine penetrasyon ve enfeksiyon yolları incelenmiştir. Penetrasyon esnasında bütün izolatların enfeksiyon yastığı oluşturduğu, ayrıca AG-3 ve AG-5’e ait izolatlarda loblu apresorium oluşumu, AG-4’e ait izolatta ise direkt hif penetrasyonu gözlenmiştir. Enfeksiyon yastıklarından oluşan çok sayıda enfeksiyon çivisi kütikuladan penetrasyon yaptıktan sonra epidermis hücreleri arasında veya içinde gelişmiştir. Apresoriumdan oluşan .