Dual Trichoderma consortium mediated elevation of systemic defense response against early blight in potato

Abstract

The annual crop loss caused due to phytopathogens is a serious problem affecting food security. To overcome the losses due to phytopathogens, the application of toxic pesticides is the only alternative but pose a serious threat to human and environmental health. Hence, more eco-friendly and sustainable approaches for efficient management of phytopathogens are urgently required. In this study, we evaluated the effectiveness of Trichoderma viride and Trichoderma harzianum as single as well as in consortium for elevating the systemic defense response and growth promotion activities in potato challenged with early blight pathogen Alternaria solani. The percent of mycelial inhibition of A. solani by T. viride (91.88%) and T. harzianum (80.11%) was recorded and compared with control. Scanning electron microscope (SEM) observations revealed the collapsed hyphae and sunken conidia of A. solani due to antagonistic activity of T. viride and T. harzianum. Induction of defense enzymes including total phenolic content (TPC), phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD) and total protein content was increased 3.19, 3.72, 1.99 and 2.5 folds, respectively in consortia of Trichoderma spp. treated plants as compared to pathogen infected plants at 48 hapi. HPLC analysis demonstrated higher production free poly-phenolic compounds during combined application of Trichoderma spp. treated potato plants in the response of A. solani infection. This study demonstrates that the consortium of Trichoderma spp. is effective in elevating the host defense response by modulating the activities of phenylpropanoid derivatives, pathogenesis related proteins (PR-proteins), enzymes of oxidative stress network, and growth parameters in potato challenged with the early blight pathogen, A. solani. © 2021, Koninklijke Nederlandse Planteziektenkundige Vereniging.