under exposure of simulated rain at pH 2.5 (Meier et al. 1989). These wide habitat
ranges of C. geophilum suggest the adaptability of the fungus against severe
environment.
Shaw and Sidle (1982) reported that the ability of live sclerotia to survive for
several years can provide sufficient inoculum to colonize host species effectively.
Indeed, C. geophilum sclerotia can be one of the most common resistant propagules
of ectomycorrhizal fungi in forest soils; they can survive drought treatments in forest
soils and germinate and form ectomycorrhizal roots on bioassay seedlings
(Glassman et al. 2015). Furthermore, Obase et al. (2018) demonstrated that genotypic diversity of C. geophilum is significantly higher in sclerotia than
ectomycorrhizal roots in the same soil samples. The results of these experiments
indicate excel abilities of C. geophilum sclerotia for maintaining genetic diversity of
the fungus and functions in forest ecosystems.
The features of sclerotia of C. geophilum has been precisely noted by Trappe
(1969) and Massicotte et al. (1992), which tend to be particularly abundant near
Cenococcum mycorrhiza, as 0.05 ~ 4 mm or more in diameter, and viable, mature
ones are jet-black, hard, smooth, mostly spherical, and often with emergent hyphae.
Trappe (1969) also noted “live sclerotia” are denser than water and have a high
content of ethanol-soluble oil (supposedly reserve substances), while “dead sclerotia”—which can persist indefinitely in soil—look much like live ones but float in
water and lack the ethanol-soluble oil. Figure 1.2 shows mycelia hyphae, mycorrhiza, sclerotia of Cg associated with thin root of various arborescent species.
Sclerotium grains can be easily found in natural forest soil, due to their shining
black spherical structure (Fig. 1.3). Attentions to sclerotium grains are able to be paid
Fig. 1.2 Top: Mycelial hyphae of C. geophilum isolate (Cg AT 353) from Pinus mycorrhiza.
Bottom Left: Mycorrhiza, hyphae, and sclerotia of C. geophilum associated with the seedling roots
of Quercus crispula Blume. Bottom Right: Thin roots of Salix reinii (Mineyanagi) attached by
jet-black hyphae and sclerotium of Cg. Sclerotium grain is denoted by an arrow
1 Introduction
5
ranges of C. geophilum suggest the adaptability of the fungus against severe
environment.
Shaw and Sidle (1982) reported that the ability of live sclerotia to survive for
several years can provide sufficient inoculum to colonize host species effectively.
Indeed, C. geophilum sclerotia can be one of the most common resistant propagules
of ectomycorrhizal fungi in forest soils; they can survive drought treatments in forest
soils and germinate and form ectomycorrhizal roots on bioassay seedlings
(Glassman et al. 2015). Furthermore, Obase et al. (2018) demonstrated that genotypic diversity of C. geophilum is significantly higher in sclerotia than
ectomycorrhizal roots in the same soil samples. The results of these experiments
indicate excel abilities of C. geophilum sclerotia for maintaining genetic diversity of
the fungus and functions in forest ecosystems.
The features of sclerotia of C. geophilum has been precisely noted by Trappe
(1969) and Massicotte et al. (1992), which tend to be particularly abundant near
Cenococcum mycorrhiza, as 0.05 ~ 4 mm or more in diameter, and viable, mature
ones are jet-black, hard, smooth, mostly spherical, and often with emergent hyphae.
Trappe (1969) also noted “live sclerotia” are denser than water and have a high
content of ethanol-soluble oil (supposedly reserve substances), while “dead sclerotia”—which can persist indefinitely in soil—look much like live ones but float in
water and lack the ethanol-soluble oil. Figure 1.2 shows mycelia hyphae, mycorrhiza, sclerotia of Cg associated with thin root of various arborescent species.
Sclerotium grains can be easily found in natural forest soil, due to their shining
black spherical structure (Fig. 1.3). Attentions to sclerotium grains are able to be paid
Fig. 1.2 Top: Mycelial hyphae of C. geophilum isolate (Cg AT 353) from Pinus mycorrhiza.
Bottom Left: Mycorrhiza, hyphae, and sclerotia of C. geophilum associated with the seedling roots
of Quercus crispula Blume. Bottom Right: Thin roots of Salix reinii (Mineyanagi) attached by
jet-black hyphae and sclerotium of Cg. Sclerotium grain is denoted by an arrow
1 Introduction
5