Characterization of fungal pathogens causing diseases in bitter gourd and establishment of their eco-friendly control measure
ME Khan Chowdhury, M Saroar Jahan, Sharmin Akhtar, M Ashikul Islam, M Asadul Islam, B Sikdar, MF Hasan
The present investigation was designed for morpho-physiological and molecular characterization of the phyto-pathogenic fungi responsible for two deleterious diseases - damping off and fusarium wilt as well as evaluation of their control technique. The pathogenic fungi were isolated from the diseased parts of bitter gourd plant collected from two different fields and primarily identified on the basis on their specific colony morphology and microscopic observation. The fungal isolates were grown well on PDA medium and showed different colony morphology on different culture media. Although the optimum pH of these fungi varied, but the optimum temperature was 25°C for both of the fungal isolates. The differences in carbohydrate types, sugar concentrations, organic acids and salts also significantly influenced the mycelial growth of these fungi. PCR products of the internal transcribed spacer (ITS) region of the fungi showed approximately 650bp size clear band in gel electrophoresis. In sequencing analysis, the amplified ITS region of the fungi showed 99% and 100% similarities with the original sequences of Fusarium equiseti and Fusarium oxysporum, respectively. In antifungal activity assay, the extracts of Ficus racemosa, Moringa oleifera, Azadirachta indica, Cassia alata, Senegalia catechu etc. displayed promising antifungal activities against both of the isolate A and B. The outcome of this research work would be helpful for detection and developing nature-friendly control approach of the two devastating diseases of bitter gourd.