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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Perennial Crops Laboratory » Research » Publications at this Location » Publication #320475
Title: Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation

Author
item GREENFIELD, MELINDA - International Center For Tropical Agriculture (CIAT)
item GOMEZ-JIMENEZ, MARIA - International Center For Tropical Agriculture (CIAT)
item ORTIZ, VIVIANA - International Center For Tropical Agriculture (CIAT)
item Vega, Fernando
item Kramer, Matthew
item PARSA, SOROUSH - International Center For Tropical Agriculture (CIAT)

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2016
Publication Date: 1/9/2016
Citation: Greenfield, M., Gomez-Jimenez, M.I., Ortiz, V., Vega, F.E., Kramer, M.H., Parsa, S. 2016. Beauveria bassiana and Metarhizium anisopliae endophytically colonize cassava roots following soil drench inoculation. Biological Control. 95:40-48.

Interpretive Summary: Cassava (Manihot esculenta) can be affected by more than 200 arthropod pests, whose attack is thought to be the most limiting production factor across many regions. Accordingly, cassava may be an excellent candidate crop to examine the full spectrum of endophytic biological control by the fungal insect pathogens Beauveria bassiana and Metarizium anisopliae. As a first step in this direction, this article describes a soil inoculation method that was effective in introducing both fungi as endophytes in the root. This information will be of use to mycologists, entomologists, microbiologists, and practitioners of biological control of insect pests.

Technical Abstract: The fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae were investigated to determine if endophytic colonization could be achieved in cassava. An inoculation method based on drenching the soil around cassava stems using conidial suspensions resulted in endophytic colonization of cassava roots by both entomopathogens. Neither B. bassiana nor M. anisopliae were found in the leaves or stems of the treated cassava plants, indicating that endophytic colonization was restricted to the roots. Both fungal entomopathogens were detected more often in the proximal end of the root than in the distal end. Colonization levels of B. bassiana were higher (84%) when plants were sampled at 7-9 days post-inoculation compared to 40% at 47-49 days post-inoculation. In contrast, the colonization levels of M. anisopliae remained constant from 7-9 days post-inoculation (80%) to 47-49 days post-inoculation, which suggests M. anisopliae is better able to persist as an endophyte in cassava roots over time. Colonization by some B. bassiana fungal treatments had a positive effect on plant growth parameters including stem length, leaf chlorophyll content, root length, and root weight.