Fusiform Ascospores Research Articles

A NEW SPECIES OF ARACHNIOTUS WITH AN OIDIODENDRON CONIDIAL STATE

A new species of Arachniotus is figured and described. This species, A. striatosporus, is characterized by having fusiform ascospores which appear striate in surface view because of the presence of five to nine more or less longitudinal ridges. The ascospores appear stellate in cross section. The species has a conidial state belonging to the form genus Oidiodendron.

Numbers and Viability of Certain Airborne Fungus Spores

SUMMARYAirborne fungus spores were studied for numbers and viability by hour-long samples from 5 AM to 9 PM in 2 series; the first on 20 days from June to September, 1959, and from June to mid-August, 1960, the second on 17 consecutive days from August 27 to September 12, and October 9. Four spore types were studied: Alternaria, Cercospora, Cladosporium, and fusiform ascospores. Spores were obtained on silicone-coated slides exposed in a slit sampler. Viability was tested by incubating spores 48 hr in a moist chamber.Diurnal periodicity was observed in spore numbers of all 4 fungi: Alternaria had peaks 10–40/ft3, occasionally higher, at 11 AM and 6 PM; Cercospora had similar peaks but numbers fewer than 10/ft3; Cladosporium, usually over 100/ft3, was variable, but twin peaks at 11 AM and 6 PM predominated; fusiform ascospores were less than 10/ft3 with a nighttime peak.Spore germination in Alternaria averaged 80% and was constant throughout the day. In Cercospora germination averaged 58% but was low at morning and night, increasing to a peak of 70–90% at 11 AM then declined. Cladosporium and fusiform ascospores averaged 42 and 55%, respectively, with viability decreasing in the morning to a midday low and increasing in the afternoon and evening.

A NEW SPECIES OF CHAETOMIUM FROM INDIAN SOILS

A new species Chaetomium fusisporale Rai & Mukerji, isolated from usar soils of Lucknow (India), is described. It has straight hairs and fusiform ascospores with a single germ pore.