PJB-2019-84
Chitinolytic activity of the indigenous Trichoderma spp. from the north west of Pakistan against the fungal phytopathogens
Shahzad Munir, Nadeem Ahmed, Muhammad Abid, Shafiq Ur Rehman, Muhammad Ashraf, Lixin Zhang And Muhammad Anees
Abstract
Chitinases are the enzymes considered as an important biocontrol mechanism for the putative antifungal activity. Here we report the chitinolytic activity of the indigenous strains of Trichoderma previously isolated from the North Western regions of Pakistan. The different strains of T. longibrachiatum TMK5, TMK6, TMK9, TMK20 and TMK21, and T. virens TMK8 isolated from the Malakand region, and T. longibrachiatum TKK3, TKK4 and TKK6 isolated from the Karak areas were included in this study. The strains were screened for their activity on the specific chitin synthetic medium in vitro at pH 4.7. The formation of purple colored zones depicted the chitinase activity by the fungi and the intensity of the colored zones was used as the criteria for the assessment. The highest activity was shown by T. longibrachiatum strain TKK4 followed by the strains TKK3, TMK5, TKK6, TMK20, and TMK21. The enzymes were then extracted in the modified Richards’s medium. The strain TMK21 showed the highest N-acetyl-β-D-glucosaminidase activity of 0.017 umol/ml/min. Endochitinase activity was noticed by the extent of reduction of colloidal chitin suspension by the tested strains. The highest endochitinase activity was shown by the strain TMK9. The strain TMK20 produced the highest enzyme unit (0.503 EU), while on the other hand, the strain TMK9 had the lowest value (0.033 EU). The crude enzymes were then applied against the phytopathogenic fungal isolates originated from the local diseased vegetables (Green Chili, Onion, Ridge Gourd, Okra, Bottle Gourd, Eggplant, Bitter Gourd and Spinach) including Fusarium spp., Alterneria spp. and Aspergillus spp. The partially purified enzymes extracted from T. longibrachiatum strains TMK20 and TMK21 consistently inhibited the different phytopathogenic fungi (up to 100%). This study demonstrated the inhibitory role of the chitinolytic enzyme extracts against the fungal pathogens.
To Cite this article:
Munir, S., N. Ahmed, M. Abid, S.U. Rehman, M. Ashraf, L. Zhang and M. Anees. 2019. Chitinolytic activity of the indigenous Trichoderma spp. from the north west of Pakistan against the fungal phytopathogens. Pak. J. Bot., 51(2): DOI: http://dx.doi.org/10.30848/PJB2019-2(37)
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