Investigations into Endophytes in Pimenta dioica L Merr

Abstract

Endophytes are a class of endosymbiotic microorganisms that colonise the inter- and/or intracellular regions of plants. They are frequently bacteria or fungi. These organisms live their entire or a portion of their lives inside their hosts, displaying no outward signs of illness. In the present study endophytic bacteria and endophytic fungi were isolated from various parts (root, stem, leaf and seeds) of Pimenta dioica (L.) Merr. (Allspice). A total of 18 endophytic bacteria and 21 endophytic fungi were isolated and screened for plant growth promoting traits such as phosphate and potassium solubilization, production of phytohormone (IAA). Antifungal activity of endophytic bacteria was checked against three fungal phytopathogens namely, Fusarium solani, Alternaria alternatae and Aspergillus niger. newlineFor the purpose of qualitative and quantitative plant growth promoting trait estimation, promising isolates having plant growth promoting traits were chosen. Plant growth promoting isolates were morphologically, biochemically and molecularly characterized. For molecular characterization of endophytic bacteria and endophytic fungi 16S rRNA and 18S rRNA gene sequencing techniques were used. newlineOut of the 18 identified bacterial isolates, three endophytic bacteria were used for pot experiments and experiments were conducted on Solanum lycopersicon cv. F1 hybris LHT- Anmol (tomato). Out of the 10 identified fungal isolates, four endophytic fungi were used for pot experiments using tomato. Application of isolates to tomato plants increased plant growth over control. In case of bacteria, maximum plant growth was promoted by Bacillus halotolerans (PdSeB2), followed by (Bacillus tequilensis) PdSeB1 and Bacillus subtilis (PdRB2). newlineIn case of endophytic fungi maximum root length was promoted by Colletotrichum crassipes (PdFR5), followed by Colletotrichum siamnese (PdFS5), Colletotrichum brevisporum (PdFSe1) and Colletotrichum gloeosporioides MR3 (PdFL1). On the other hand maximum shoot length was promoted by PdFSe1 followed by PdFR5, PdFS5 and PdFL1. newline newline