EFFICACY OF Trichoderma species FROM HILL BANANA AGRO-ECOSYSTEM AGAINST Fusarium oxysporum f.sp. cubense
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Date
2018
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Publisher
AAU, Jorhat
Abstract
The use of biological control agents (BCAs) has gained its popularity in
agriculture as a way to decrease the application of synthetic pesticides. In the genus
Trichoderma, a great number of fungal strains have been studied and utilized as
BCAs. Exploration of biocontol agents from hill agro- ecosystem has not been
intensified from the North Eastern states of India. Under the backdrop, the present
investigation was carried out to explore potential Trichoderma spp. from the state of
Nagaland. Eight numbers of Trichoderma spp. isolated from hill banana rhizospheric
soils from different sub-divisions of the districts, Wokha, Kohima, and Dimapur had
been culturally and morphologically characterized. In vitro antagonistic activity of all
the eight isolates were carried out against Fusarium oxysporum f.sp. cubense (FoC),
the causal organism of Fusarium wilt of banana. The study revealed that all the 8
isolates significantly inhibited the growth of FoC at different levels in all intervals of
incubation (72, 120 and 168 hours). Of the isolates, three viz S37-4, S41G and S39
found to be most effective in inhibiting the mycelial growth of the test pathogen with
77.8 per cent, 75.0 per cent and 75.0 per cent respectively. The strains were identified
as Trichoderma asperellum (S37-4) and Trichoderma virens (S41G and S39).
Enzymatic assays of the isolates revealed significant increase in chitinase and β-1, 3
glucanase. Trichoderma asperellum (S37-4) was found with the maximum activity of
cell wall degrading enzymes (CWDEs) i.e., chitinase (32.4 nkat/sec) and β-1, 3
glucanase (171.85 nkat/sec) in comaparison to other two isolates. An investigation
was also carried out to study the production of volatile and non-volatile compounds
by the Trichoderma spp. and found significant reduction of mycelial growth of the
test pathogen was recorded. Trichoderma asperellum (S37-4) recorded the maximum
inhibition of the growth of the test pathogen in both the cases of volatile (59.33%) and
non-volatile (74.4%) compounds.