Vol. 12, Issue 8 (2023)

Author(s):
AG Gathe, ST Ingle, SS Mane, SB Brahmankar and ADVR Teja

Abstract:
This study aimed to use chemical mutagenesis and irradiation to improve the genetics of Trichoderma asperellum in order to improve its biocontrol efficiency. T. asperellum mother culture was chemically mutated with ethyl methyl sulphonate (EMS) and hydroxyl amine (HA) at 200 µl/ml and physically mutated with gamma radiation (cobalt 60) at 250 gry and ultraviolet (UV) rays at 254 nm wavelength. The duration of all treatments was 30, 45, 60 and 75 min. After mutagenesis, 16 mutants were tested for their stability up to seven generations. All mutants and parent cultures of T. asperellum were distinguished by cultural and morphological features. The mutants showed strong antagonistic activities against the tested soil pathogens. The highest rate of growth inhibition of Sclerotium rolfsii was recorded in the TaH2 (T₂) mutant, i.e., 88.89%. While Fusarium oxysporum f.sp. ciceri and Rhizoctonia bataticola, the highest growth inhibition rates were recorded in the TaU3 (T₁₁) and TaG1 (T₁₃) mutants, 62.82 and 75.38%, respectively. All mutants recorded higher chitinase enzyme compared with culture samples. The TaH2 (T₂) mutant recorded the highest level with 0.98 units/mg protein of chitinase enzyme activity, while the parent culture TaMc (T₁₇) contained only 0.62 units/mg protein of chitinase enzyme activity.