Mating type analyses of Ascochyta rabiei isolates

ABSTRACT MATING TYPE ANALYSES OF Ascochyta rabiei ISOLATES KÜLEKÇİ, Şule M.Sc. in Biology Supervisor: Asst. Prof. Dr. Canan Can January 2004, 61 pages Ascochyta rabiei (Pass) Labr. (teleomorph: Didymella rabiei (Kovacheski) v. Arx (=Mycosphaerella rabiei Kovacheski) is a heterothallic loculoascomycete fungus with a bipolar mating system. The fungus causes Ascochyta blight of chickpea {Cicer areitinum L.) which is one of the main disease of chickpea worldwide, as well as our coutry (Akem 1999; Güllü et al., 2002). The mating system of A. rabiei has not been estimated in the field, but based on the laboratory mating behaviour of the fungus (Wilson and Kaiser, 1995). In this study, the isolates were collected from the South-eastern Anatolia, Gaziantep provinces and its towns between 2001-2003 cultivation periods. Mating type analyses of isolates were practised with both classical and molecular methods. Discrimination of 120 isolates that were collected from several arable fields in the South-eastern Anatolia region were used in based on morphological and population analyses studies. Although ascocarps were never found in the microscopic observations using classical methods in the mating type analyses which induce sexual development of fungus, thanks to molecular studies, the overall ratio of mating type, is valid worldwide, that was obtained for some areas. The study is the first report for our region and the results obtained provide the basis for the future studies on the population analyses of A. rabiei. Key words: Cicer arietinum L., Ascochyta rabiei, mating type u