Vol. 12, Issue 7 (2023)

Author(s):
Nisha Thakur, Gopinath V, Amit and Gopal Krishna Awadhiya

Abstract:
The effects of environmental variables like temperature, pH and wavelength of light on the development, phenotypic expression, and sporulation of Alternaria lini were investigated. To determine the optimal temperature, the petridishes were incubated at 10 °C, 15 °C, 20 °C, 25 °C, 30 °C and 35 °C, Smooth texture with circular growth pattern, gray color of margin with thick mycelium appearance at 25 °C. Pigmentation ranges from black at 20 °C, 25 °C, 30 °C, 35 °C and brown at 10 °C and 15 °C. Sporulation was found excellent at 25 °C and 30 °C, good at 20 °C and 35 °C, moderate at 15 °C and poor at 10 °C. According to the results of the pH study, the optimal conditions for mycelial growth were found to be pH 6 (89.33 mm), followed by pH 7 (75.33). Mycelial growth was observed to be moderate at pH 8 (68.67 mm), then it was observed to be moderate at pH 9 (56.67 mm), and the mycelial growth was observed to be minimal at pH 4 (26.00 mm), then it was observed to be minimal at pH 5 (47.00 mm).Sporulation was found excellent at pH 6 and 7, good at pH 8, moderate at pH 5 and 9, poor at pH 4. Study on wavelength depicted that maximum mycelial growth observed in fluorescent white light (90.00 mm) followed by blue (82.67 mm) and yellow (73.67 mm). Sporulation was found excellent in yellow, blue and fluorescent white, good in red and violet, moderate in green. Pigmentation observed black in all the wavelength of light. Sporulation was found to be moderate in green, but excellent in yellow, blue, and fluorescent white. It was found to be excellent in red and violet, but only good in green. The investigation concluded that the optimal wavelength of light for the growth and sporulation of Alternaria lini was fluorescent white light, followed by blue light in second place.