First Report on Rhizome Rot Disease of <i>Curcuma longa</i> Caused by <i>Fusarium solani</i> in Bangladesh

Abstract

Turmeric (Curcuma longa L.) is a valuable medicinal plant as well as spice crop in Bangladesh. The rhizome rot disease is a severe danger to turmeric cultivation. The current study sought to identify the fungal pathogen linked to turmeric rhizome rot disease. Rhizome of turmeric with distinct rotted symptoms was collected from the experimental site of the Botanical Garden, Jahangirnagar University, Bangladesh. The sample was screened to isolate the causative fungal pathogen through the tissue planting technique. Macro and micro-morphological characterization based on colony appearance, mycelial and conidial characteristics primarily identified the fungus as Fusarium sp. The ITS sequence of rDNA of the fungus exhibited 99 to 100 percent similarity with the other F. solani species formerly deposited in the NCBI database which confirmed the fungal identity as F. solani. An in vitro pathogenicity test validated the pathogenic nature of the fungus. Growth behaviors of the fungus were evaluated on different solid culture media viz., Potato dextrose agar, Potato sucrose agar, Sabouraud dextrose agar and Hansen’s agar; temperature conditions (10?C, 15?C, 20?C, 25?C, 30?C and 35?C) and pH levels (pH 4, pH 5, pH 6, pH 7 and pH 8). Maximum mycelial growth was obtained on PSA medium at 30?C temperature and pH 7 conditions. Current findings also conclude that F. solani favors a wide range of temperature and pH levels. To the best of our search, the present investigation revealed the relationship of F. solani with the rhizome rot disease of turmeric for the first time in Bangladesh.