Interactions of Bacillus Mojavensis and Fusarium Verticillioides With a Benzoxazolinone (Boa) and Its Transformation Product, Apo

En:Journal of Chemical Ecology (2007, vol. 33, n. 10, p. 1885-1897)The benzoxazolinones, specifically benzoxazolin-2(3H)-one (BOA), are important transformation products of the benzoxazinones that can serve as allelochemicals providing resistance to maize from pathogenic bacteria, fungi, and insects. However, maize pathogens such as Fusarium verticillioides are capable of detoxifying the benzoxazolinones to 2-aminophenol (AP), which is converted to the less toxic N-(2-hydroxyphenyl) malonamic acid (HPMA) and 2-acetamidophenol (HPAA). As biocontrol strategies that utilize a species of endophytic bacterium, Bacillus mojavensis, are considered efficacious as a control of this Fusarium species, the in vitro transformation and effects of BOA on growth of this bacterium was examined relative to its interaction with strains of F. verticillioides. The results showed that a red pigment was produced and accumulated only on BOA-amended media when wild type and the progeny of genetic crosses of F. verticillioides are cultured in the presence of the bacterium. The pigment was identified as 2-amino-3H-phenoxazin-3-one (APO), which is a stable product. The results indicate that the bacterium interacts with the fungus preventing the usual transformation of AP to the nontoxic HPMA, resulting in the accumulation of higher amounts of APO than when the fungus is cultured alone. APO is highly toxic to F. verticillioides and other organisms. Thus, an enhanced biocontrol is suggested by this in vitro study. =580 $aEn:Journal of Chemical Ecolog

New Species of Ascomycetes and a New Genus of Sphaeropsidaceae from Transvaal*

A new genus of Sphaeropsidaceae, Oncostroma Batista & Marasas, and its type species O. toddaliae Batista & Marasas, are described. Five new species of Ascomycetes,  Brasiliomyces entadae Marasas & Rabie,  Thyriopsis sphaerospora Marasas,  Microcyclus halleriae Marasas & Rabie,  Phyllachora ehrhartae Marasas and  Trichopeltum africanum Batista & Marasas, are described. Two new com­binations,  Trichopeltum carissae (Doidge) Marasas and  Trichopeltum kentaniensis (Doidge) Marasas, are made

Cotton Staining caused by Crebrothecium ashbyi (= Eremothecium ashbyi) in South Africa

A description is given of  Crebrothecium ashbyi (Guill.) Routien  (— Eremothecium ashbyi Guill.) which was isolated from yellow stained cotton fibres. This fungus, in association with cotton Stainer insects, caused extensive cotton staining in the Vaalharts area o f the Cape Province during 1969-1970

The Genus Pithomyces in South Africa

Descriptions are given of South African isolates of  Pithomyces sacchari (Speg.) M. B. Ellis, Pithomyces chartarum (Berk. & Curt.) M. B. Ellis and  Pithomyces karoo  Marasas & Schumann, sp. nov.  P. sacchari and P. chartarum were isolated from Medicago sativa L. seed.  P. chartarum was also isolated from dead leaves of Lolium perenne L. and  Sporobolus capensis (Willd.) Kunth. plants from artificial pastures in the eastern Cape Province.  P. karoo was isolated from stems of Gnidia polycephala (C.A. Mey.) Gilg and  Rhigozum trichotomum Burch, from the Karoo, Cape Province and from Avena sativa L. stubble collected in the Orange Free State

Notes on Southern African Tuberales

Three species of Tuberales have been found in Southern Africa.  Terfezia pfeilii Henn. occurs in the Kalahari Desert and adjacent areas of the Cape Province, Botswana and South-West Africa. The other two,  Terfezia austroafricana sp. nov. and  Choiromyces echinulatus sp. nov., are known only from the Cape.  C. echinulatus is the first representative of that genus to be collected in Africa or the Southern Hemisphere

A new species of <i>Phaeoramularia</i> (Fungi Imperfecti: Dematiaceae) from South Africa

A dematiaceous Hyphomycete isolated fro n wheat and oat straw, as well as lucerne seed in South Africa, is described as Phaeoramularia kellermaniana Marasas & Bred ill, sp. nov. The relationships ofP. kellermaniana to  Cladosporium resinae (Lindau) de Vries and other species of Phaeoramularia are discussed

Two Species of Erysiphaceae from Pretoria

No abstract availabl