Isolation of endophytic fungi from wild rice species for disease management and growth promotion in cultivated rice (Oryza sativa L.)

Abstract

ABSTRACT The focus of plant health management is shifting from synthetic chemicals to bio-agents, and endophytes are beneficial for this purpose. In the present study, we isolated eleven endophytic fungi from seven wild rice species. Independent treatment of endophytic fungi in rice showed significant improvements in plant growth, higher tillering and percent fertility, panicle number/hill and filled grain number in endophyte-inoculated plants compared to control plants. Growth promotion activities of two endophytes Curvularia lunata (NRRI EF-11) and Hypocreals sp. (NRRI EF-8) were recorded with increased rice yield. These isolates also exhibited higher plant growth promoting chemicals namely, Indole acetic acid (IAA) and Inorganic phosphate (IP) which was realised into better growth promotion in rice. The biocontrol efficacy of endophytic fungi was highest in NRRI EF-11among all isolates as indicated by inhibition of radial growth of pathogens by 76.98–77.06% and in NRRI EF-8 by 74.81–76.61%, which is due to higher production of prussic acid. Defense induction was confirmed by analyzing the expression of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) defense enzymes, where expression of CAT, POD and SOD increased by 19.44–25.86, 2.70–3.16, 11.14–12.95 Units g−1 in treated NRRI EF-11 plants and 18.39–25.84, 2.16–2.94, 10.96–12.62 Units g−1 in treated NRRI EF-8 plants, respectively. These two endophytes have the potentiality to manage crop health in a sustainable way.