In vitro and in vivo characterization of charcoal rot disease (Macrophomina phaseolina) in sesame

Abstract

Objective: This study aimed to characterize charcoal rot pathogen (Macrophomina phaseolina) of sesame in vitro and in vivo. Material and Methods: In 2017, two isolates of M. phaseolina were isolated from symptomatic sesame plants in Aksu district of the Western Mediterranean region of Türkiye. Pathogenicity tests were conducted using cv. Muganlı-57 in a greenhouse. Micromorphological characteristics (colony growth, colony color, mycelium, and microsclerotium) and chlorate sensitivity of the isolates were determined in vitro. Effects of temperature on colony growth and symptoms of charcoal rot in the field were also examined in detail. Results: Significant (P<0.01) differences were detected in microsclerotium length, microsclerotium width, and colony growths of the isolates on minimal medium. Both isolates were characterized as chlorate-sensitive. On minimal medium, Aksus1 isolate displayed a feathery growth pattern, while Aksus2 isolate showed a restricted growth pattern. Temperature significantly (P˂0.01) affected colony growth. The highest colony growths were detected at 35°C, while the lowest ones were found at 40°C. Conclusion: The results may provide new insights into the epidemiology of the charcoal rot disease. To the best of our knowledge, this is the first detailed characterization of microscopic traits and charcoal rot symptoms on sesame in the field in the Western Mediterranean region of Türkiye.