Two Philippine Photorhabdus luminescens strains inhibit the in vitro growth of Lasiodiplodia theobromae, Fusarium oxysporum f. sp. lycopersici, and Colletotrichum spp.

Abstract Background Fungal phytopathogens are one of the leading causes loss in global food production. Chemical fungicides have always been used to control mitigate losses. However, it is widely known that this approach not sustainable. Thus, essential develop alternative methods, such as use biological agents. Results This study provided a preliminary data on efficacy 2 local Photorhabdus strains, associated with Heterorhabditis indica BSDS and H. MAP, against selected post-harvest fungal phytopathogens, Fusarium oxysporum f. sp. lycopersici, Lasiodiplodia theobromae, Colletotrichum musae, another sp . , by measuring their vitro inhibitory activity. The strains were isolated from hemolymph Ostrinia furnicalis infected MAP grown selectively NBTA media. Firstly, bacterial endosymbionts' generic identity was confirmed through colony PCR based Txp40 toxin-specific marker. Species then elucidated 16s marker-assisted GenBank mining P. luminescens, sharing 99.51–99.58% similarity luminescens subsp. akhurstii (Accession no. AY278643.1). Anti-fungal activity observed bioassay experiments, using cell-free culture filtrates (CFCs), obtained tryptic soy broth suspensions (OD 600 = 2.0) amended PDA medium (25%v/v) percentage growth inhibition. CFCs showed significantly higher suppressive sp., 93.18 ± 0.46%, 74.15 0.54%, 60.51 2.04% inhibition, respectively, while CFC F. lycopersici 21.87 0.71% Conclusions results strongly these can be promising agents phytopathogens. Further extensive research warranted for development biofungicides into practical, economically viable, environment-friendly strategy incorporated any integrated pest management program.