TY - JOUR
T1 - Interactions Between Two Invertebrate Pathogens
T2 - An Endophytic Fungus and an Externally Applied Bacterium
AU - Wakil, Waqas
AU - Tahir, Muhammad
AU - Al-Sadi, Abdullah M.
AU - Shapiro-Ilan, David
N1 - Funding Information:
This research work was financially supported (2AV1-257) by Higher Education Commission, Islamabad, Pakistan.
Publisher Copyright:
© Copyright © 2020 Wakil, Tahir, Al-Sadi and Shapiro-Ilan.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
Copyright © 2020 Wakil, Tahir, Al-Sadi and Shapiro-Ilan.
PY - 2020/11/30
Y1 - 2020/11/30
N2 - The members of family Noctuidae exist in diverse environments and many species from this group are of agriculture importance, particularly Helicoverpa spp. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a major pest of many legumes and cereal crops. Due to environmental and regulatory concerns, safe alternatives to broad spectrum chemical insecticides are needed for the control of key noctuid pests such as H. armigera. A strain of Beauveria bassiana (Cordycipitaceae: Hypocreales) was evaluated for its ability to colonize endophytically in chickpea plants, and its effectiveness against second (L2) and fourth (L4) larval instars of H. armigera. B. bassiana was inoculated to chickpea plants through injection and endophytic establishment was confirmed by re-isolating the fungi from leaf samples. A detached leaf assay was used to evaluate pathogenicity. Bacillus thuringiensis was also applied to both larval stages through leaf dip method. In a novel approach, combined treatments of bacteria and endophytic fungi were compared with single-pathogen treatments. Relative to the single treatments, the combined pathogen treatments exhibited an increase in larval mortality, and decrease in pupation, adult emergence and egg eclosion. Specifically, synergistic effects on mortality were observed when larvae were exposed to simultaneous application of B. bassiana (1 × 108 conidia ml–1) with B. thuringiensis (0.75 μg ml−1). Both instars exhibited varying level of growth, development, frass production, diet consumption and fecundity when exposed to the chickpea leaves inoculated with endophytic B. bassiana and dipped with sub-lethal doses of B. thuringiensis. These findings indicate that the integrated application of endophytic colonized B. bassiana and B. thuringiensis can be effectively used against H. armigera.
AB - The members of family Noctuidae exist in diverse environments and many species from this group are of agriculture importance, particularly Helicoverpa spp. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a major pest of many legumes and cereal crops. Due to environmental and regulatory concerns, safe alternatives to broad spectrum chemical insecticides are needed for the control of key noctuid pests such as H. armigera. A strain of Beauveria bassiana (Cordycipitaceae: Hypocreales) was evaluated for its ability to colonize endophytically in chickpea plants, and its effectiveness against second (L2) and fourth (L4) larval instars of H. armigera. B. bassiana was inoculated to chickpea plants through injection and endophytic establishment was confirmed by re-isolating the fungi from leaf samples. A detached leaf assay was used to evaluate pathogenicity. Bacillus thuringiensis was also applied to both larval stages through leaf dip method. In a novel approach, combined treatments of bacteria and endophytic fungi were compared with single-pathogen treatments. Relative to the single treatments, the combined pathogen treatments exhibited an increase in larval mortality, and decrease in pupation, adult emergence and egg eclosion. Specifically, synergistic effects on mortality were observed when larvae were exposed to simultaneous application of B. bassiana (1 × 108 conidia ml–1) with B. thuringiensis (0.75 μg ml−1). Both instars exhibited varying level of growth, development, frass production, diet consumption and fecundity when exposed to the chickpea leaves inoculated with endophytic B. bassiana and dipped with sub-lethal doses of B. thuringiensis. These findings indicate that the integrated application of endophytic colonized B. bassiana and B. thuringiensis can be effectively used against H. armigera.
KW - Bacillus thuringiensis
KW - Beauveria bassiana
KW - chickpea
KW - endophytic colonization
KW - Helicoverpa armigera
UR - http://www.scopus.com/inward/record.url?scp=85097630560&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85097630560&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2020.522368
DO - 10.3389/fmicb.2020.522368
M3 - Article
C2 - 33329412
AN - SCOPUS:85097630560
SN - 1664-302X
VL - 11
SP - 522368
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
M1 - 522368
ER -