Comparative Assessment of Temperature-dependent Radial Growth and Spore Production of Entomopathogenic Fungi under in vitro Conditions
Subhashree Patnaik *
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
Amit Kumar Sharma
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
S. B. Das
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
Manish Gadekar
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
Abhishek Shukla
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
Ritu Pandey
Department of Entomology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004, Madhya Pradesh, India.
*Author to whom correspondence should be addressed.
Abstract
Temperature strongly influences the growth and reproductive potential of entomopathogenic fungi used in biological pest control. This study examined the effects of four temperatures (22, 26, 30, and 34 °C) on radial growth and spore production of two Beauveria bassiana isolates and two Metarhizium anisopliae isolates under in vitro conditions. Fungal cultures were grown on PDA media, and radial growth was measured at 3, 7, and 14 days, while spore production was quantified on day 15. The experimental findings revealed that temperature significantly affected both parameters, with 26 °C supporting the highest mycelial expansion and spore yield, followed by 22 °C. Higher temperatures (30–34 °C) caused substantial reductions due to thermal stress. Among isolates, B. bassiana local showed superior performance, while M. anisopliae MTCC-984 was least responsive. Overall, the findings show that moderate temperatures optimize fungal growth and conidiation, with B. bassiana demonstrating greater thermal tolerance.
Keywords: Temperature, entomopathogenic fungi, beauveria bassiana, metarhizium anisopliae, radial growth, Spore production