Author/Authors :
bayraktar, harun ankara üniversitesi - ziraat fakültesi - bitki koruma bölümü, Turkey , yılmaz, olgac ankara üniversitesi - ziraat fakültesi - bitki koruma bölümü, turkey , özer, göksel abant izzet baysal üniversitesi - ziraat ve doğa bilimleri fakültesi - bitki koruma bölümü, Turkey
Abstract :
Cumin blight caused by Alternaria burnsii is an important fungal disease restricting cumin productionin many countries. The pathogen is widespread in almost all cumin growing areas in Turkey and causesmajor economic losses. However, little information is known about morphologic, phenotypic andphylogenetic characteristics of Alternaria burnsii. In this study, the effect of different nutrient mediaand environmental factors on mycelial growth and sporulation of Alternaria burnsii was studied, andmorphological differences among the pathogen isolates were evaluated. For this purpose, pathogenisolates were grown on seven different nutrient media (Potato Dekstrose Agar, Potato Carrot Agar, CornMeal Agar, Czapek Dox Agar, Sucrose Agar, Water Agar, Tomato Juice Agar, V88) under twodifferent incubation conditions. Among the culture media evaluated, the highest sporulation wasobtained on V88 media exposed to the alternating temperature and light regimes. Also, the length,width and septa number of the conidia showed statistically differences depending on culture media andgrowing conditions. The temperature was a significant limiting factor affecting the pathogen growth.The best growth was observed at 25 °C. Phylogenetic analysis of the rDNA-ITS sequences performedby UPGMA method indicated that all tested isolates clustered in the same group and these isolates werephylogenetically distinct from the isolates of Alternaria-species groups, representing different sectionsretrieved from GenBank. These results could provide useful information in the pathogen inoculum production for further studies as well as the development of different methods for the identification and determination of the pathogen.
