Abstract
Crude extracts of in vitro and in vivo cultures of two strains of Photorhabdus l. sonorensis (Enterobacteriaceae) were analyzed by TLC, HPLC-UV and LC-MS. Nine unique compounds with mass/charge ratios (m/z) ranging from 331.3 to 713.5 were found in MS analyses. Bioactivity of extracts was assessed on a selection of plant pathogens/pests and non-target species. Caborca strain extracts showed the highest activity against Helicoverpa zea (Lepidoptera: Noctuidae) neonates at all concentrations tested. Mortality ranged from 11% (at 10 μg/ml) to 37% (at 40 μg/ml). Strain CH35 extracts showed the highest nematicidal activity on Meloidogyne incognita (Tylenchida: Meloidogynidae) at 40 μg/ml. Low to no nematicidal activity was observed against the non-target species Steinernema carpocapsae (Rhabditida: Steinernematidae) and Caenorhabditis elegans (Rhabditida: Rhabditidae). Caborca extracts exhibited a strong antibiotic effect on Pseudomonas syringae (Pseudomonadales: Pseudomonadacedae) at 40 μg/ml, while both Caborca and CH35 extracts inhibited the growth of Bacillus subitillis (Bacillales: Bacillaceae) at 40 μg/ml. All extracts strongly inhibited the growth of the fungus Fusarium oxysporum (Hypocreales: Nectriceae) but not that of Alternaria alternata (Pleosporales: Pleosporaceae). Contrastingly, a moderate to high inhibitory effect was denoted on the non-target biocontrol fungus Beauveria bassiana (Hypocreales: Clavivipitaceae).
Original language | English |
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Pages (from-to) | 45-52 |
Number of pages | 8 |
Journal | Journal of Invertebrate Pathology |
Volume | 141 |
DOIs | |
Publication status | Published - 1 Nov 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Bioactivity
- Crude extracts
- Photorhabdus
- Plant-pathogens
- Secondary metabolites