Ascomycetes cont

– Taphrina caerulescens
Powdery mildew of rose – Sphaerotheca pannosa
Ergot of

rye – Claviceps purpurea

Today
Brown rot of stone fruit – Monilinia fructicola
Nectria canker of apple and other trees – Nectria cinnabarina
Dutch elm disease – Ophiostoma novo-ulmi

of stone fruit
Greatly influenced weather
A fruit disease but can cause

blossom blight and twig blight
Fungal penetration of fruit can result in latent infection that develops only after the fruit has ripened

trees
Results in cankers that can reduce vigor or kill small

trees
Cankers can produce sexual and asexual spores every year
Control by pruning and using dormant spray afterwards

Produces sexual spores in perithecia and asexual spores on sporodochia

spread to the east
and west coasts

severe on American elm
Death of tree may occur in weeks

or years
A heterothallic fungus – require strains of opposite mating types
Two types of asexual conidia produced as well as sexual spores
Infect plant xylem and clogs the conductive tissue with gels, gums, tyloses, and fungal tissue

bark beetles
Produces sticky spores in the galleries and at the

gallery exits.
When mature beetles exit to find new trees, they are covered with fungus spores
The spores are deposited in the wounds at the beetle feeding sites

Perithecia
5) Pseudothecia

Sporocarps

stages.
These fungi are those that may have lost the

need to produce sexual spores, or for which no sexual state has yet been identified.

This is a problem, because fungal identification is based on production of sexual spores.

If no sexual stage, then what? Answer = artificial group (Deuteromycetes). Within this artificial group, there is classification based on conidia production.

important diseases

Often the secondary disease cycle

Spore stage is conidia

the "Mycelia Sterilia" or sterile mycelia. Ex: Sclerotium, Rhizoctonia

Fungal nomenclature:
This

means that a given fungus can be assigned one Genus name for the sexual stage and another for the asexual stage. However the sexual stage is always the correct name.

it for years and call it by its imperfect name,

then someone discovers the sexual stage and renames it?
From then on, the fungus must be officially referred to by the sexual name. But often both names are kept, especially if there is a large body of literature under the old name.
Then you'll see reference to sexual name (= teleomorph, i.e., married name) first followed by asexual name (= anamorph, i.e., maiden name) in parentheses.
Ex: Rhizoctonia solani / Thanatephorus cucumeris
Thanatephorus cucumeris (anamorph Rhizoctonia solani)

by the sexual stage, then Genus names for the asexual

stages are not used.
Ex: Cryphonectria parasitica is the teleomorph. The asexual spore is produced in a pycnidium, but the pycnidial stage is never identified with a name.
It is referred to as the pycnidial stage of the chestnut blight fungus.

Ex: Ophiostoma ulmi produces 2 asexual stages - Graphium stage, Cephalosporium stage.

Most imperfect fungi have perfect stages that are in Ascomycetes. A few (ca. 25 or so) are Zygomycetes or Oomycetes, and fewer still are Basidiomycetes.