Sphaerodes

Abstract: The present invention relates to a novel ascomyceteous fungus, Sphaerodes mycoparasitia strain IDAC 301008-01, for controlling Fusarium plant pathogens, disease symptoms, and mycotoxins in planta and ex planta. Uses, methods, compositions, sequences, and products are also disclosed herein.

Abstract: The two new species, Sphaerodes quadrangularis and Sphaerodes tenuissima, isolated from soil in Spain, are described and illustrated. The former can be easily distinguished from the other species of the genus by the peculiar polygo- nal section of their ascospores. The most noteworthy feature of Sphaerodes tenuissima is the smooth-walled appearance of its ascospores, which is unusual in the genus. The new combinations Sphaerodes ellipsospora, Sphaerodes levita, and Sphaerodes singaporensis are proposed and a key to the accepted species of the genus is provided. Taxonomic novelties: Sphaerodes quadrangularis D. Garcia, Stchigel & Guarro sp. nov., Sphaerodes tenuissima D. Garcia, Stchigel & Guarro sp. nov., Sphaerodes ellipsospora (Takada) D. Garcia, Stchigel & Guarro comb. nov., Sphaerodes levita (Udagawa & Cain) D. Garcia, Stchigel & Guarro comb. nov., Sphaerodes singaporensis (Morinaga, Minoura & Udagawa) D. Garcia, Stchigel & Guarro comb. nov.

Abstract: Five pyrenomycete isolates found in asso- ciation with different form species of Fusarium oxy- sporum were evaluated for their in vitro ability to par- asitize the watermelon wilt pathogen (E oxysporum f. sp. niveum). Several assays were also developed that attempted to measure damage to the wilt pathogen directly in culture. The pyrenomycetes used for path- ogenicity and parasitism tests included three isolates of Sphaerodes retispora var. retispora, and one each of Melanospora zamiae and Persiciospora moreaui. A col- lection of 24 different isolates of E oxysporum was employed to define a parasitic host range for this group of pyrenomycetes within the species oxyspo- rum. The ability to sporulate on the Fusarium hosts was the primary criterion used for establishing host ranges. Results indicated that all five isolates were ca- pable of parasitizing the wilt pathogen, but P moreaui was the only one that caused no detectable damage in both the aerial hyphal reduction and growth in- hibition assays. Melanospora induced significant dam- age with the growth inhibition assay only. Significant differences were observed among and between the pyrenomycetes and the different form species in terms of ability to parasitize and reproduce.