Experimental and physiological ecology of ammonia fungi: studies using natural substrates and artificial media

Abstract

Experiments using natural substrates and artificial media were categorized into three groups. Using experiments in these three categories, we investigated dispersion, invasion sequence, and decomposing ability of ammonia fungi in the field on natural substrates. Spore germination and vegetative and reproductive growth of ammonia fungi derived from monocultures and five-species cultures were assessed on natural substrates and on artificial media. These features assist understanding of the colonization and successive occurrence of ammonia fungi in the field based on estimation of interactions among the fungi and the physiological characteristics of each ammonia fungus. The sequential colonization and fruiting of ammonia fungi in the field can be explained primarily by the preference or tolerance of a species to high concentrations of ammonium-N under alkaline to neutral conditions. Succession of ammonia fungi results from their sequential colonization associated with the time needed for each fungus to produce reproductive structures. Colonization likely initiates from mycelia and/or spores preinhabiting the soil and from newly invading airborne propagules. Duration of occurrence of ammonia fungi in the field is shortened by the interactions among them. Saprobic ammonia fungi are the principal agents of litter decomposition under alkaline to neutral conditions.

Effects of pH, NH4-N concentration, temperature, and storage period on basidiospore germination in an ectomycorrhizal ammonia fungus Hebeloma vinosophyllum

“…According to the sequential occurrence of ammonia fungi in the fi eld, they are divided into two types, early-phase fungi (EP fungi) and late-phase fungi (LP fungi). The former type species are saprobic fungi and living propagules of several EP fungi in the fi eld (Suzuki et al 2002;Suzuki 2006) and the spore longevity of the LP fungus H. spoliatum (Suzuki 2003). However, we do not yet have enough data to elucidate the propagation mechanism of each ammonia fungus.…”

Interactions among ammonia fungi on MY agar medium with varying pH

“…Yamanaka (1999Yamanaka ( , 2003 pointed out that the successive appearance of ammonia fungi from EP to LP species may be controlled by the changes in both pH and the form of inorganic nitrogen. Suzuki (1989Suzuki ( , 2006 also proposed that the sequential propagation of each ammonia fungi may be explained by their preference of or tolerance to high concentrations of ammonium nitrogen under alkaline to neutral conditions as well as by their adaptation to different pH conditions.…”

“…In the former, physiological characteristics of spore germination (Suzuki 1978(Suzuki , 1989(Suzuki , 2006Suzuki et al 1982), vegetative growth, and reproductive structure formation (Morimoto et al 1981(Morimoto et al , 1982Enokibara et al 1993;Soponsathien 1998a,b;Yamanaka 1999Yamanaka , 2001Yamanaka , 2003He and Suzuki 2003;Suzuki 2006;Licyayo and Suzuki 2006) have been examined. In the latter, only Suzuki (2006) made preliminary studies of interspecifi c interactions among a few ammonia fungi and reported that the early-stage EP fungi Amblyosporium botrytis and Ascobolus denudatus showed mutual intermingling under acidic to alkaline conditions and that the LP fungus Hebeloma vinosophyllum increased fruiting and invaded into the colony of Amblyosporium botrytis under acidic conditions. The objective of this article is to examine and characterize the in vitro interactions among members of ammonia fungi and to provide insight into how these interactions infl uence their vegetative and reproductive growths in the natural habitat resulting in their successive occurrence.…”

Dynamics of fruit-body production and mycorrhiza formation of ectomycorrhizal ammonia fungi in warm temperate forests in Japan

“…Authors of these studies fi rst considered fruit-body assemblages (Bills et al 1986; ammonia fungi are rarely seen under natural conditions, they are not necessarily dependent on artifi cial disturbance for their growth and reproduction. They are considered to be latent inocula in soils (Sagara 1976b;Suzuki et al 2002;Suzuki 2006) of forests in various areas and to be adapted to many kinds of local but frequent input disturbances, e.g., animal excretions, carcasses, or giant-hornet wastes (Sagara et al 1985;Sagara 1989Sagara , 1995Wang and Sagara 1997;Fukiharu et al 2000a,b;Harmaja 2002;Kasuya 2002;Oda et al 2002).…”