L. W. Burgess

One fungus, one name

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.

One fungus, one name: defining the genus Fusarium in a scientifically robust way that preserves longstanding use.

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.

Survey of Fusarium species associated with crown rot of wheat and barley in eastern Australia

Fusarium species associated with crown rot were isolated and identified from 409 wheat, barley or durum wheat crops from the eastern Australian grain belt between 1996 and 1999. Fusarium pseudograminearum was almost the only species isolated from crops in Queensland and New South Wales. F pseudograminearum was also the most common species in Victoria and South Australia, but F. culmorum was frequently isolated in these states. F. culmorum accounted for more than 70% of isolates from the Victorian high-rainfall (> 500 mm) region and the South-East region of South Australia. F culmorum comprised 18% of isolates from the Victorian medium-rainfall (350–500 mm) region, and 7% of isolates from each of the Victorian low-rainfall region and the Mid-North region of South Australia. F avenaceum, F crookwellense and F. graminearum were isolated very infrequently. The proportion of F. culmorum among isolates of Fusarium from districts in Victoria and South Australia was strongly correlated with climatic conditions around the end of the growing season, especially with rainfall in November.

Characterization and distribution of Fusarium nygamai, sp. nov.

ABSTRACTFusarium nygamai is described and illustrated. The key features of this species are the formation of microconidia in relatively short chains as well as false heads and the production of rou...

Climatic analysis of the distribution of Fusarium graminearum, F. pseudograminearum and F. culmorum on cereals in Australia

The distributions of Fusarium graminearum (Gibberella zeae), F. pseudograminearum (F. graminearum Group 1) and F. culmorum from cereals in Australia were determined from published survey data and accessions to culture collections. The distributions were analysed in terms of climate, using the climate matching system BIOCLIM. F. graminearum was found mostly in warm temperate to subtropical areas with moderate to high summer rainfall, where mean temperature of the warmest quarter was greater than 18.7°C and rainfall of the warmest quarter was greater than 195 mm. This appeared to be due to the effect of climate on production of maize, the host from which most records were obtained. F. pseudograminearum occurred throughout the main cereal growing areas and its occurrence did not appear to be limited by climate within the Australian grain belt. The distribution of F. culmorum on cereals was more limited than that of F. pseudograminearum. In the southern winter rainfall zone, F. culmorum was restricted to sites with mean summer temperatures less than about 22°C and annual rainfall greater than about 350 mm, whereas in the northern summer rainfall zone F. culmorum was restricted to areas with mean summer temperatures less than about 24.5°C and annual rainfall greater than about 625 mm.

Molecular genetic investigations and reclassification of Fusarium species in sections Fusarium and Roseum.

The genetic relationships of 56 isolates from the taxa traditionally grouped in Fusarium sections Fusarium (syn. Discolor ) and Roseum were studied using the Restriction Fragment Length Polymorphism (RFLP) technique, by Southern hybridisation with random genomic and mitochondrial DNA probes originating from Fusarium species. Pairwise distances between taxa were calculated from the 957 RFLP bands scored on autoradiograms, using Dices coefficient in the RAPDistance computer program. A strong genetic relationship was observed between F. graminearum, F. culmorum and F. crookwellense . However, the morphologically similar taxon, F. pseudograminearum shared only approximately 40 % of genomic DNA RFLP bands with these taxa, demonstrating affinity, but less direct genetic similarity. Of all taxa examined F. pseudograminearum and F. graminearum shared the greatest similarity in mitochondrial DNA RFLP patterns. F. avenaceum subsp. avenaceum , subsp. aywerte and subsp. nurragi displayed very little genetic resemblance with each other, or with F. heterosporum and the cereal infecting pathogens. F. torulosum was closest genetically to subsp. avenaceum , with approximately 22 % of genomic DNA RFLP bands in common. On the basis of these results F. avenaceum subsp. aywerte and subsp. nurragi are elevated to species rank, as F. aywerte comb. nov. and F. nurragi comb. nov., and F. avenaceum subsp. avenaceum is returned to its former species status.

Mycogeography of Fusarium: survey of Fusarium species in subtropical and semi-arid grassland soils from Queensland, Australia

Fusarium species were isolated from grassland soil samples from four areas located along the Tropic of Capricorn between Rockhampton on the east coast and Boulia on the margin of the Simpson Desert in Queensland, Australia. Fusarium species were isolated by plating root debris on Selective Fusarium Agar, and by the dilution plate technique on peptone PCNB agar. The five most frequently isolated species were F. chlamydosporum, F. compactum, F. equiseti, F. nygamai and F. solani, all of which were isolated from each sampling area. F. chalmydosporum, F. compactum and F. equiseti were isolated more frequently from the drier sampling areas. F. solani was isolated more frequently from Rockhampton, a wetter, subtropical area. F. longipes was only isolated from the Rockhampton area. F. beomiforme was isolated frequently from the Rockhampton area, one culture was obtained from the Emerald area, and it was not isolated from the two driest areas. Five species. F. moniliforme, F. napiforme, F. oxysporum, F. scirpi and F. semitectum, and the undescribed population were isolated infrequently.

Mycogeography of Fusarium species in soils from tropical, arid and mediterranean regions of Australia

Twenty-two Fusarium species as well as three undescribed populations were recovered from 42 sites representing three different climatic regions: Darwin (tropical), Alice Springs (arid) and Ceduna (mediterranean). These species were F. acuminatum subsp. acuminatum, F. anthophilum, F. avenaceum subsp. aywerte, F. beomiforme, F. chlamydosporum, F. compactum, F. dimerum, F. equiseti, F. graminearum Group 1, F. lateritium, F. longipes, F. merismoides, F. moniliforme, F. napiforme, F. nygamai, F. oxysporum, F. polyphialidicum, F. proliferatum, F. semitectum, F. scirpi, F. solani, F. subglutinans . Fifteen species were recovered from soils from the tropical region, 13 species and three undescribed populations from the arid region and seven species from the mediterranean region. Species found in all three regions were F. dimerum, F. equiseti, F. solani and F. oxysporum . Species recovered only from tropical soils were F. beomiforme, F. longipes, F. moniliforme and F. subglutinans. F. nygamai and F. scirpi were only recovered from arid soils; and F. a. acuminatum was only recovered from the mediterranean region. F. chlamydosporum and F. compactum were isolated frequently from soils in the tropical and arid regions but were more abundant in the arid soils from Alice Springs.

Characterization, geographic distribution and ecology of Fusarium crookwellense sp.nov.

Fusarium crookwellense is described and illustrated. Initial isolates were from potato tubers from the Crookwell area of New South Wales, Australia. Additional isolates have been recovered from wheat, corn, barley, Paspalum sp., Pinus sp. and debris from temperate and tropical pasture soils from various locations in Eastern Australia. Isolates from a variety of host plants and debris from soil have been obtained from the U.S.A., South Africa, France, Colombia, and China. Descriptions of the sporodochial cultures and macroconidia are given and compared to F. sambucinum, F. culmorum, F. robustum , and F. graminearum. F. crookwellense is generally more abundant in temperate high rainfall or irrigated areas.

Distribution of Fusarium species in sections Roseum, Arthrosporiella, Gibbosum and Discolor recovered from grassland, pasture and pine nursery soils of eastern Australia

Fusarium species in sections Roseum, Arthrosporiella, Gibbosum, and Discolor were common in grassland, pasture, and pine nursery soils of eastern Australia. The grasslands consisted of grazing land...