Table 1.
Designations, hosts, isolation data and GenBank accession numbers of the rDNA-ITS and ACT sequences of the 26 Ampelomyces strains included in the current work.
Table 2.
Morphological characteristics of Ampelomyces spp. fungi subcultured on Czapex-Dox agar medium supplemented with 2% malt (MCzA).
Fig 1.
Phylogenetic tree with the highest likelihood value resulting from the maximum likelihood (ML) analysis of ITS and ACT sequences of 129 Ampelomyces strains, including 26 isolated in this study (written in bold) in Japan.
The tree is rooted to Phoma herbarum strain CBS56763 based on an earlier study [17]. Bootstrap values calculated from 1000 replicates in ML analysis are written as percentages (values below 70% and in subclades are not shown). These are followed by posterior probabilities resulting from Bayesian analysis (no values are shown below 0.9 and in subclades), separated by slashes. Bar indicates 0.02 expected changes per site per branch. Additional data on Ampelomyces strains (place and data of collection, host fungal species) and GenBank accession numbers of sequences included in the analyses are listed in earlier studies [17, 22].
Table 3.
Results of the mycoparasitic tests with eight Ampelomyces strains and five powdery mildew species, and morphological characteristics of pycnidia produced in conidiophores of tomato powdery mildew KTP-03.
Fig 2.
Digital (A and B) and light micrographs (C) of Ampelomyces strain Xs-q on tomato powdery mildew KTP-03 mycelia. A, mature (Py1) and immature pycnidia (Py2) formed onto KTP-03 mycelia. B, Pycnidium (Py) produced in KTP-03 conidiophores (Cp). C, Spores (Sp) appeared from a pycnidium after adding a drop of distilled water (10 μL). Micrographs were taken at 14 days after spray inoculation of spores onto 10-day-old KTP-03 mycelia. Bars represent 50 μm (A) and 30 μm (B and C). Hp, Hypha of tomato powdery mildew KTP-03.
Fig 3.
Digital (A and B) and light micrographs (C to F) of Ampelomyces strain Xs-q in tomato powdery mildew KTP-03. A, KTP-03 hyphae infected tomato type I trichome cells. B, Xs-q hyphae invaded into KTP-03 conidium. Arrow shows invasion site of Xs-q hypha. C, Xs-q hyphae grown into KTP-03 hyphae and primary conidiophore. D, Xs-q hyphae grown and pycnidium produced in a KTP-03 conidiophore. E, Xs-q pycnidium produced in a KTP-03 conidiophore and abundant spores appeared from the pycnidium. F, Xs-q pycnidia produced in KTP-03 conidiophores formed on tomato type I trichome cell. Bars represent 60 μm (A and F) and 20 μm (B to E). Ahp, Xs-q hypha; Co, KTP-03 conidium; Cp, KTP-03 conidiophore; Hp, KTP-03 hypha; Py, Xs-q pycnidium; Sp, Xs-q spore; Tc, Tomato type I trichome cell.
Fig 4.
Infection process of Ampelomyces strain Xs-q in tomato powdery mildew KTP-03.
KTP-03 vigorously grew on tomato type I trichome cells. Digital micrographs were taken at 0 (A), 2 (B), 3 (C), 5 (D), 6 (E) and 7 days (F) after inoculation of a pycnidium onto tomato leaf in the vicinity of the trichome cells. KTP-03 conidiophores (Cp) and hyphae (arrowed) atrophied after invasion of Xs-q hyphae (Ahp) into KTP-03 hyphae. Bars represent 20 μm.
Fig 5.
Pycnidial formation processes of Ampelomyces strain Xs-q in KTP-03.
A KTP-03 mycelium was formed on tomato leaf at 10 days after inoculation of a KTP-03 conidium with micromanipulation technique. Digital micrographs were taken at 0 (A), 5 (B), 7 (C), 10 (D) and 12 days (E) after spray inoculation of Xs-q spores onto the 10-day-old KTP-03 mycelium. KTP-03 conidiophores (Cp), formed near the trichome cell (Tc), completely atrophied after invasion of Xs-q hyphae (Ahp) into KTP-03 hyphae (arrows). Xs-q pycnidia (Py) were successfully produced in KTP-03 conidiophores. Bars represent 20 μm.