Suzanne Bullock

Gibberella konza (Fusarium konzum) sp. nov. from prairie grasses, a new species in the Gibberella fujikuroi species complex

The Gibberella fujikuroi species complex (Fusarium section Liseola and allied taxa) is composed of an increasingly large number of morphological, biological and phylogenetic species. Most of the known species in this group have been isolated from agricultural ecosystems or have been described from a small number of isolates. We sampled Fusarium communities from native prairie grasses in Kansas and recovered a large number of isolates that superficially resemble F. anthophilum. We used a combination of morphological, biological and molecular characters to describe a new species, Gibberella konza (Gibberella fujikuroi mating population I [MP-I]), from native prairie grasses in Kansas. Although female fertility for field isolates of this species appears to be low, G. konza is heterothallic, and we developed reliably female fertile mating population tester strains for this species. The F. konzum anamorph is differentiated from F. anthophilum and from other Fusarium species in section Liseola by mating compatibility, morphology, AFLP fingerprint profile and differences in β-tubulin DNA sequence.

Fusarium species associated with plants in Australia

Fusarium species associated with plants as pathogens, saprobes and endophytes in Australia are listed with notes on their pathogenicity and toxicity provided. A list of Fusarium species not known to occur in Australia also is provided and their quarantine significance evaluated.

Natural occurrence of perithecia of Gibberella coronicola on wheat plants with crown rot in Australia

Abstract.The natural occurrence of perithecia of Gibberella coronicola T. Aoki & O’Donnell, the cause of crown rot of wheat, on wheat residues in the Moree district of New South Wales is reported. Cultures established from single ascospores taken from fertile perithecia of the fungus produced its anamorph, Fusarium pseudograminearum O’Donnell & T. Aoki. The morphology of the fungus is compared with published descriptions of perithecia produced in crossing experiments in culture. No differences were observed in the morphology or the dimensions of the fungus from the two sources. Additional keywords: Fusarium pseudograminearum, Ascomycete.

Pathogens of the Wollemi pine, Wollemia nobilis

Cuttings of the Wollemi Pine, Wollemia nobilis, were inoculated with Phytophthora cinnamomi, Botyosphaeria sp., Rhizoctonia sp., Fusarium oxysporum and F. solani. P. cinnamomi and the Botyosphaeria sp. were pathogenic causing plant death over a period of up to 5 weeks. None of the other fungi caused significant disease although two out of nine plants inoculated with F. oxysporum died during the experimental period. The results confirm the necessity to maintain strict hygiene and entry controls on the site where this extremely rare plant is found.

An emended description of Fusarium brevicatenulatum and F. pseudoanthophilum based on isolates recovered from millet in Kenya

Cultures morphologically similar to F. brevicatenulatum and F. pseudoanthophilum were recovered from millet collected in Kenya. Morphological characterisation showed that the production of pyriform microconidia and chlamydospores, key characters separating these species from each other and from other Fusarium species, was variable in these cultures. Sexual compatibility studies of these isolates and holotype cultures of F. brevicatenulatum and F. pseudoanthophilum revealed that they belonged to the same biological species. No fertile crosses were observed between putative isolates of F. brevicatenulatum from millet and tester strains of F. verticillioides, F. sacchari, F. proliferatum, F. subglutinans, F. thapsinum, and F. konzum. Neither were fertile crosses obtained from any self-cross tests, indicating that the cultures were heterothallic. Further studies using AFLP, and sequencing of the β-tubulin, calmodulin, and translation elongation factor 1-α genes revealed that the isolates from the millets and those of the ex-holotype cultures of F. brevicatenulatum and F. pseudoanthophilum belonged to the same species. The species epithet F. brevicatenulatum is preferred on the basis of priority.

Vascular wilt of basil in Australia

Fusarium wilt of basil, caused by Fusarium oxysporum f. sp. basilici, occurs worldwide but has not been officially recorded in Australia. Fourteen isolates of F. oxysporum were collected from diseased basil from a number of locations in Australia. A PCR diagnostic test previously shown to react only with isolates of F. oxysporum f. sp. basilici was used to identify the isolates and Koch’s postulates were performed for a subset of isolates to confirm pathogenicity. Two techniques, vegetative compatibility grouping and DNA fingerprinting using enterobacterial repetitive intergenic consensus (ERIC) targeted primers, were used to analyse all isolates. Diagnostic PCR confirmed that 11 of the isolates were F. oxysporum f. sp. basilici and they were shown to belong to a single VCG and to have a single ERIC profile, indicating that the population is essentially clonal. This is the first report of this pathogen in Australia.

Occurrence of perithecia of Gibberella fujikuroi mating population A (Fusarium moniliforme) on maize stubble in northern Vietnam

Perithecia of Gibberella fujikuroi were found on old maize (Zea mays) stalks in northern Vietnam. Single ascospores from these perithecia produced cultures of the anamorph Fusarium moniliforme but ...

First record of vascular wilt of flannel flower caused by Fusarium oxysporum

Fusarium oxysporum was isolated from flannel flowers (Actinotus helianthi) which were severely wilted. Isolates of the fungus were used to inoculate healthy seedlings. Symptoms, similar to those observed in the original seedlings, were observed after 17 weeks and the fungus re-isolated.

Stem rot of Sturt’s desert pea caused by Botrytis cinerea

A stem rot of Sturt’s desert pea was observed in a nursery in New South Wales. Plants were grown under cover and the weather coinciding with the disease outbreak was 2–3 weeks of high humidity. Botrytis cinerea was sporulating profusely on the base of the stem and was isolated from sections of stem tissue. Pathogenicity tests confirmed this fungus as the pathogen.

News from the executive

The executive has decided the Constitution of APPS is in urgent need of updating. Many of the Clauses are now irrelevant and others have not been followed for a number of years. In 1986, Members were invited, through their Regional Councillors, to send any amendments they felt appropriate to the Secretary and these have been used as the basis for many changes. The Executive will propose that the Constitution be amended at the General Meeting in Adelaide in May 1987. Copies of the present Constitution and the proposed amendments will be sent to all Regional Councillors by the end of February 1987. Any Member who wishes to study them may do so by contacting their Regional Councillor. Two further motions will be put to the General Meeting. Firstly, the Executive will propose that the