Lecture #11

Aphyllophorales

Polypores, Chantharelles, Tooth Fungi, Coral Fungi and Corticoids

Approximately 1200 described species

Aphyllophorales can be grouped as those hymenomycetes that possess holobasidia but usually lack gills

Most species are saprobic in soil, litter, bark, dead wood or the non-conducting xylem (heart wood) of living trees

Some species may be truely parasitic or pathogenic on trees, non-woody crops, nonvascular plants; also mycorrhizal forms associated with forest trees

Many polypores decay wood of trees that are already dead, however, some fungi of the Polyporaceae, Hymenochaetaceae, Stereaceae and Heriaceae enter via the wounds of living trees and decay heart wood

Heart-rot and Butt-rot examples

Some heart-rot and butt rot fungi are pathogenic and can kill living trees by attacking functional vascular tissue. Phellinus pini is important in the decline of the Douglas-fir stage of succession in cedar-hemlock forests.

Several heart and butt rot fungi (e.g.,Heterobasidium annosum, Phellinus weirii and Inonotus tomentosus) are able to survive as mycelium in dead root systems for long periods of time (decades) and provide an inoculum to infect roots that come into contact with dead fungus-bearing roots. These long-lived fungi are a significant problem in second growth and managed forests.

Fungal rots are also common in houses, utility poles, pilings, etc.; dry rot

Some wood inhabiting fungi which include members of the Polyporaceae, Corticiaceae, Cantharellanceae and Thelephoraceae are ectomycorrhizal with forest trees

Importance to animals

Red-cockaded Woodpecker: the reduction in number of birds has been linked to the loss of older southern pines with extensive heart rot caused by Phellinus pini (Conner and Locke, 1982)

Managed southern stands are harvested on a shorter rotation of 80 years that is necessary for substantial heart-rot to take place

The extinction of the Ivory-billed Woodpecker was most probably a similar situation with the substantial decrease on mature old growth hardwood forests with substantial decay.

Medicinal and Cultural uses

Ganoderma lucidum- Ling Chi; chinese herbal medicine; reported as cures for multiple diseases: venereal disease to cancer, purification of blood, lowering of cholesterol.

Up to 12 species of Phellinus have been used in Indian folk medicine (Vaibya & Rabba, 1993)

Antibiotics have been isolated from several members of Aphyllophorales (Quack et al., 1978)

Fompitopsis officinalis

• Basidiocarps or conchs were carved into figures and used by the shamans of AmeriIndians of the Pacific Northwest
• Basidiodarp preparations were also administered medicinally and associated with supernatural healing forces

• Sparassis crispa
  
• Albatrellus spp.
  
• Grifola frondosa
  
• Hericium erinaceum
  
• Laetiporus sulphureus
  
• Cantherellus spp.
  

Wood Decay

White rotters

• More common
• Fungi produce extracellular enzymes that breakdown cell components lignin, hemicellulose and cellulose simultaneously and approximately equal rates

Brown rotters

• Usually associated with conifers in more boreal regions
• Not all brown rotters are Aphyllophorales
• Approximately 10% of wood decaying fungi in North America are brown rotters, but 80% of these occur on conifers; significant rot of conifers
• Extensive depolymerization of cellulose and hemicellulose but minimal degradation of lignin
• brown rot residues known as humus, may remain in soil for 3000 years and are essential to the continued renewal of coniferous ecosystems

Taxonomy

Generative hyphae - septate, may be clamped, walls thin, present in all badidiocarps; give rise to basidia and to vegetative hyphae

Vegetative hyphae - lack septae and consist of two types

• Skeletal hyphae - unbranched, walls thick, and growth may be indeterminant
• Binding hyphae - ligative hyphae, branched and sinous, walls thick to thin, more restricted growth

Monomitic- basidiocarp consisting of only generative hyphae

Dimitic- basidiocarp consisting of generative hyphae and either skeletal or binding hyphae

Trimitic- basidiocarp consisting of generative, skeletla and binding hyphae

Gloeopleurous hyphae- thin walls, highly refractive contents and bright staining with phloxine or Melzer's reagent

Sterile elements

Xanthochroic reaction - blackening of tissue in KOH

Cystidia - sterile elements that arise in the hymenium of subhymenium; typically long and slender and extend beyond hymenium; maybe encrusted with crystals of calcium oxalate

Cystidioles - resemble immature basidia, distinguished by pointed tips (lance-like)

Major Families

• Largest most diverse group; the "chaotic mass" (Donk, 1971)
• Over 700 species
• Mono-, di- & trimitic
• White & brown rotters
• Basidiospores are usually hyaline and lack ornamentation
• Setae do not occur in basidiocarp hymenium or trama
• No xanthochroic reaction
• Basidiocarps may be crusts, shelves, conchs or mushrooms

• Stipitate basidiocarps
• Dimitic with binding hyphae
• White rot
• Once large genus that has been split into many genera (Gilberson &Ryvarden, 1987)

Fomes

• Hard, shelf-like fruiting body
• Trimitic hyphae
• Perennial, produce new hymenophore over old one each season

Trametes versicolor

• Most common species of Polyporaceae
• White rotter
• Velvety pileus surface with distinctive concentric zones of brown, grey or red
• The "turkey-tail" fungus

Hymenochaetaceae

Well delimited based on microscopic characters; quite variable basidiocarp development among species
White rotters
Lack clamo connections
Possess setae
Septal pore cap is not perforated
Positive xanthocroic reaction
Basidiocarps are golden brown to reddish brown
Basidiospores are smooth and hyaline or brown

Poroid forms

• Inonotuswith annual basidiocarps
• Phellinuswith perennial basidiocarps
• Both are common heart and root rots

Resupinate forms

• Hymenochaeteproduces a smooth hymenium
• Hydnochaeteproduces a toothed hymenium

Ganodermataceae

• Poroid species with distinctive basidiocarps
• Pileus surface often with varnished apperance
• Basidiospores - ovoid, usually truncate at one end, golden brown, surface punctate
• White-rotters
• Ganoderma applanatum, oregonense, tsugae

Schizophyllaceae

• Schizphyllum commune
• Basidiocarp - gray, cup-shaped, hirsutate (hairy), small (1-4 cm)
• Lamellae - split lamellae not homologous with gills of mushrooms white-rotter

Cantherellanceae

Cantherellus

• Basidiocarp - pileus that taper gradually to a stalk (cantharelloid) and may have a deeply depressed pileus center (funnel shaped)
• Folds in hymenophore resemble shallow attached gills that descend down the stalk
• Monomitic - generative may or not be clamped according to species
• Cantharelloid growth form is found in a number of unrelated groups

Cantherellus and Craterellus

• Terrestrial and mycorrhizal
• Craterellus- funnel-shaped basidiocarp, dark-colored, no clamp connections
• Cantherellus- brightly colored, possess clamp connections

Clavariaceae

• The club or coral fungi
• Mostly monomitic, some dimitic systems
• +/- clamp connections according to taxon
• Mostly saprobic in soil or dead wood, some mycorrhizal
• Some species of Clavulinopsis are lichenized
• Clavariaceae and Cantherellaceae possess similar slender basidia that may be indicate a relatively close relationship

Sparassidaceae

• Species produce large, light colored monomitic basidiocarps at the base of
• Living trees
• Possess clamp connections
• Resemble pale colored cabbage
• Sparassis crispa- brown rot of roots of western North American conifers

Stereaceae

• Stereum
• Wood-decaying and terrestrial fungi
• Basidiocarps - resupinate, effused-reflexed, or stalked and pileate
  • usually dimitic with skeletal hyphae
  • leathery, corky or woody

• +/- clamp connections
• Most species are white rotters
• Pileus may be zoned as in Trametes but the pores of the hymenophore are minute compared to the large diameter pores of Trametes

Corticiaceae

• Rivals the Polyporaceae in numbers of species
• Artificial grouping based on:
  • resupinate basidiocarp that are primarily lignicolous
  • hyphal construction in usually monomitic
  • +/- clamps
  • hymenophore may be smooth or wrinkled

• Many produce calcium oxalate depositions on hyphae and basidiocarps

Phanerochaete- large crystals encrusting tips of cystidia

Many possess stephanocysts

• Sterile elements arising from mycelium or hymenial layer
• Adhesive organs for the capture of nematodes
• Mucilage on surface of stephanocysts adheres to nematode cuticle

Hydnaceae

• Terrestrial
• Basidiocarp - fleshy, stipitate, pileate
• Hymenophore - toothed; toothed hymenium has occured many times in evolution of fungi
• Monomitic with clamp connections
• Lack cystidia
• Hydnum repandum, imbricatum

Heriaceae

• Hyphal construction is mostly commonly monomitic with clamp connections
• Basidiospores are amyloid
• Possess gloeoporous hyphae
• Hericium erinaceus- the "bear's head" - grows on wounds of living hardwoods
• Hericium abietis- spruce

Thelephoraceae

• Basidiocarp ranging from resupinate to pileate to branched clavarioid forms
• Hymenophore smooth, toothed, poroid or folded
• Monomitic and +/- clamps
• Lignicolous and some species are mycorrhizal
• Thelephora terrestris mycorrhizal member