Analyzing influence of thermal and osmotic stress on native isolates of Fusarium oxysporum f.sp. cubense

Fusarium oxysporum f.sp. cubense is an important pathogen of banana causing panama disease that results in significant losses in yield worldwide. A study was conducted with an emphasis on the effect of abiotic stress on Fusarial wilt causing pathogen in banana. Fusarial wilt affected banana psuedostem were collected from different places of district Katihar, Bihar, India based on characteristic symptoms. Pure culture of four isolates A3, A5, A6 and B1 were obtained after confirming the pathogenicity and molecular confirmation on the basis of presence of effector genes Secreted In Xylem 9a and Translation elongation factor 1 α . All isolates showed optimum growth at 25 °C whereas no growth was observed at 40 °C. Maximum sporulation was observed at temperatures 30 °C and 35 °C with minimum at 20 °C. Decrease in osmotic potential of the media lead to reduction in mycelial growth with a minimum at 8 MPa whereas decrease in osmotic potential lead to enhanced sporulation in native isolates of Fusarium oxysporum f.sp. cubense. The results are discussed in light of abiotic stresses in the said region in form of high summer temperatures and frequent flooding.