Plant beneficial traits of endophytic bacteria associated with fennel (<i>Foeniculum vulgare</i> Mill.)

Abstract

<abstract> <p>In this study, we used 16S rRNA gene sequence analysis to describe the diversity of cultivable endophytic bacteria associated with fennel (<italic>Foeniculum vulgare</italic> Mill.) and determined their plant-beneficial traits. The bacterial isolates from the roots of fennel belonged to four phyla: <italic>Firmicutes</italic> (BRN1 and BRN3), <italic>Proteobacteria</italic> (BRN5, BRN6, and BRN7), <italic>Gammaproteobacteria</italic> (BRN2), and <italic>Actinobacteria</italic> (BRN4). The bacterial isolates from the shoot of fennel represented the phyla <italic>Proteobacteria</italic> (BSN1, BSN2, BSN3, BSN5, BSN6, BSN7, and BSN8), <italic>Firmicutes</italic> (BSN4, BRN1, and BRN3), and <italic>Actinobacteria</italic> (BRN4). The bacterial species <italic>Bacillus megaterium</italic>, <italic>Bacillus aryabhattai</italic>, and <italic>Brevibacterium frigoritolerans</italic> were found both in the roots and shoots of fennel. The bacterial isolates were found to produce siderophores, HCN, and indole-3-acetic acid (IAA), as well as hydrolytic enzymes such as chitinase, protease, glucanase, and lipase. Seven bacterial isolates showed antagonistic activity against <italic>Fusarium culmorum</italic>, <italic>Fusarium solani</italic>, and <italic>Rhizoctonia. solani</italic>. Our findings show that medicinal plants with antibacterial activity may serve as a source for the selection of microorganisms that exhibit antagonistic activity against plant fungal infections and may be considered as a viable option for the management of fungal diseases. They can also serve as an active part of biopreparation, improving plant growth.</p> </abstract>