Phylogeny and Optimization of Trichoderma harzianum for Chitinase Production: Evaluation of Their Antifungal Behaviour against the Prominent Soil Borne Phyto-Pathogens of Temperate India

Abstract

Trichoderma is the most commonly used fungal biocontrol agent throughout the world. In the present study, various Trichoderma isolates were isolated from different vegetable fields. In the isolated microflora, the colony edges varied from wavy to smooth. The mycelial forms were predominantly floccose with hyaline color and conidiophores among all the strains were highly branched. Based on morphological attributes, all the isolates were identified as Trichoderma harzianum. The molecular identification using multilocus sequencing ITS, rpb2 and tef1α, genes further confirmed the morphological identification. The average chitinase activity varied from 1.13 units/mL to 3.38 units/mL among the various isolates, which increased linearly with temperature from 15 to 30 °C. There was an amplified production in the chitinase production in the presence of Mg+ and Ca2+ and Na+ metal ions, but the presence of certain ions was found to cause the down-regulated chitinase activity, i.e., Zn2+, Hg2+, Fe2+, Ag+ and K+. All the chitinase producing Trichoderma isolates inhibited the growth of tested pathogens viz., Dematophora necatrix, Fusarium solani, Fusarium oxysporum and Pythium aphanidermatum at 25% culture-free filtrate concentration under in vitro conditions. Also, under in vivo conditions, the lowest wilt incidence and highest disease control on Fusarium oxysporum was observed in isolate BT4 with mean wilt incidence and disease control of 21% and 48%, respectively. The Trichoderma harzianum identified in this study will be further used in formulation development for the management of diseases under field conditions.

Trichoderma Species: Our Best Fungal Allies in the Biocontrol of Plant Diseases—A Review

“…Culture filtrate from T. harzianum can inhibit the growth of the bean pathogen Pythium ultimum and, combined with chamomile extract, reduces disease symptoms in Phaseolus vulgaris seeds caused by this pathogen [ 120 ]. Cell-free culture filtrates improved in chitinase activity, showed fungal growth inhibition against the pathogens Dematophora necatrix , F. solani , F. oxysporum , and Pythium aphanidermatum , and the effect is concentration-dependent, were at a concentration of 25% of the filtrate showed the maximum growth inhibition rate for all the pathogens tested [ 121 ]. The G-protein signal regulatory mechanism is involved in fungal processes such as pathogenesis and secondary metabolism synthesis [ 182 ], and the Thga3 subunit from T. harzianum Th33 is involved in its mycoparasitic ability against R. solani , regulating chitinase activity, hydrophobicity, and growth of the fungus [ 117 ].…”

Fungistatic Effect of Ipomea Carnea Extract and Trichoderma Esperellum Against Various Fungal Biological Agents

“…The combination of chitin and cellulose as the main constituents of fungal cell walls becomes the target of biological hydrolysis of chitin into N-acetyl-Dglucosamine monomer which will be further used by Trichoderma fungi as a source of carbon and energy [29,30]. On the other hand, both the isolate Tc-Jjr-02 as a tester and the two isolates tested (Tc-Ba-05 and Tc-Sdj-09) were from the Trichoderma genera which have chitinase enzymes [31,32] which in this test are neutral or neutral. the fungistatic effect of T. asperellum Tc-Jjr-02 did not appear to work against Tc-Ba-05 and Tc-Sdj-09.…”

In Vitro Study of Biocontrol Potential of Rhizospheric Microorganisms Against Fusarium Oxysporum F.SP. Albedinis

“…A disc of each pathogenic strain was placed in the center of the petri dish individually for use as control. Fungal pathogens growth inhibition was expressed as a percentage of radial growth inhibition relative to the control 7 days after incubation at 27 °C (Girish and Bhavya, 2018;Lahlali et al, 2020;Marimuthu et al, 2020;Kumar et al, 2021;Mohiddin et al, 2021). Mycelial growth assessment: After 7 days of inoculation, the inhibition zones were measured and used to determine the inhibition rate using the formula below as described by Benouzza et al (2020) The bacterial strain isolated from the rhizosphere of date palm was characterized by colonies small size, rounded and regular shape, smooth aspect and a white color.…”