title: Plant growth-promoting fungus Penicillium spp. GP15-1 enhances growth and confers protection against damping-off and anthracnose in the cucumber.
abstract: Plant growth-promoting fungi (PGPF) have the potential to confer several benefits to plants in terms of growth and protection against pests and pathogens. In the present study, we tested whether a PGPF isolate, Penicillium spp. GP15-1 (derived from zoysiagrass rhizospheres), stimulates growth and disease resistance in the cucumber plant. The use of the barley grain inoculum GP15-1 significantly enhanced root and shoot growth and biomass of cucumber plants. A root colonization study revealed that GP15-1 was a very rapid and efficient root colonizer and was isolated in significantly higher frequencies from the upper root parts than from the middle and lower root parts during the first 14 d of seedling growth. Inoculating the cucumber seedlings with GP15-1 significantly reduced the damping-off disease caused by Rhizoctonia solani, and the disease suppression effects of GP15-1 were considerably influenced by the inoculum potential of both GP15-1 and the pathogen. Treatment with the barley grain inoculum or a cell-free filtrate of GP15-1 increased systemic resistance against leaf infection by the anthracnose pathogen Colletotrichum orbiculare, resulting in a significant decrease in lesion number and size. Molecular and phylogenetic analyses of internal transcribed spacer sequences of the genomic DNA of GP15-1 revealed that the fungal isolate is a strain of either Penicillium neoechinulatum or Penicillium viridicatum.
authors.affiliation: United Graduate School of Agricultural Sciences, Gifu University.
authors.forename: Md Motaher
authors.initials: MM
authors.lastname: Hossain
authors.forename: Farjana
authors.initials: F
authors.lastname: Sultana
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Miyazawa
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Hyakumachi
mesh_terms: D020231:Colletotrichum / Q000472:pathogenicity; D018553:Cucumis sativus / Q000254:growth & development* / Q000382:microbiology; D004271:DNA, Fungal / Q000235:genetics; D010407:Penicillium / Q000737:chemistry* / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology* / Q000517:prevention & control*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D012232:Rhizoctonia / Q000472:pathogenicity; D058441:Rhizosphere
chemical_list: D004271:DNA, Fungal; D010937:Plant Growth Regulators