Endophytic colonization of Solanaceае family plants by fungal entomopathogen Beauveria bassiana strain 339 to control Colorado potato beetle (Leptinotarsa decemlineata Say)

Mariana Petkova , Velichka Spasova-Apostolova, Veselina Masheva, Daniela Atanasova and Nurettin Tahsin

Abstract: In the current study, molecular identification of Beauveria bassiana isolate 339 was done by partial sequence analysis of ITS1-5.8-ITS2 region of the nuclear ribosomal DNA with universal primers. Biochemical characterization was conducted by Biolog FF MicroPlate. The efficiency of the endophytic colonization of B. bassiana strain 339 was studied by two methods of inoculation – leaf spraying and soil drench in tobacco, tomatoes, eggplant and pepper. The distribution of the fungus within the plant parts was established by incubation of explants on a selective nutrient medium. Colonization of the stems, roots and leaves of the plants from B. bassiana strain 339 was reported on the 7th, 14th and 28th day after inoculation. The results showed that B. bassiana strain 339 endophytically colonized various tissues in the studied plants of the Solanaceae family within 28 days after inoculation. The second objective of the study focused on the efficacy of B. bassiana strain 339 against adults and larvae of the Colorado potato beetle (Leptinotarsa decemlineata Say) in the laboratory experiment. There was a gradual increase in the entomopathogenic effect on the 7th day after treatment, when 90% mortality of larvae and 40% mortality of adult insects were reported. These studies show the possibility of expanding the use of the entomopathogenic fungus B. bassiana to control pests of plants of the family Solanaceae.

Keywords: Beauveria bassiana; endophytic colonization; Leptinotarsa decemlineata; Solanaceae family

Date published: 2021-09-16