The Distribution of Cytoplasm and Nuclei within the Extra-radical Mycelia in Glomus intraradices, a Species of Arbuscular Mycorrhizal Fungi

Nuclear distribution within the extra-radical fungal structures and during spore production in the arbuscular mycorrhizae fungus Glomus intraradices was examined using an in vitro monoxenic culture system. A di-compartmental monoxenic culture system was modified using a nitrocellulose membrane and a coverglass slip for detailed observations. Nuclear distribution was observed using the fluorescent DNA binding probes SYBR Green I and DAPI. Both septate and non-septate mycelial regions were observed, but cytoplasmic contents were only found within non-septate mycelia. Nuclear fluorescent staining revealed that the non-septate hyphal region contained nuclei only with cytoplasm, and that nuclear distribution was limited by septa. Swollen hyphal bodies were often associated with septate and empty-looking hyphae. Cytoplasmic contents filled the swollen hyphal body from the non-septate hyphal region following removal of the septa. As a consequence, the swollen body developed into a new spore. These observations provide understanding about the distribution of AM fungal nuclei within extra-radical mycelia and during spore formation. The results suggest a mechanism by which the development of a cytoplasm-containing mycelium is controlled by the formation or removal of septa to efficiently maintain and proliferate essential contents. This mechanism may provide a survival strategy to the fungus.

Distribution of fungus spores in the air of outdoor and indoor environments from September to November 1999 in Seoul, Korea / 천식및알레르기

BACKGROUND AND OBJECTIVES: Fungi cause allergies and are difficult to avoid in daily life. People spend much of their time indoors, but distribution of fungi spores the indoor and outdoor invironment is not well known in this country. The aim of this study was to measure fungus spores indoor and outdoor environment simultaneously and to investigate any relationships in fungus spores between indoor and outdoor environments. METHOD: We collected samples from 198 households from September to November, 1999. Burkard Personal Volumetric Air Sampler was used to collect airborne fungus spores. RESULTS: Mean number of indoor spores was 603 sp/m2 and 1,214 sp/m2 for outdoors. Cladosporium was the most predominant fungus both indoors and outdoors, followed by Leptospheria spp., Massarina spp., Alternaria spp. in order from September( indoor 928 sp/m2, outdoor 2,123 sp/m2) to November( indoor 95 sp/m2, outdoor 344 sp/m2). There were significant correlations between number of spores, and temperature and wind velocity(p<0.05), but no significant correlations with humidity. CONCLUSION: Cladosporium spp. followed by Leptospheria, Massarina and Alternaria were the predominant fungi for both indoor and outdoor environments from September to November in Seoul.