quiz 9 Flashcards
Major classes within the Pezizomycotina
Sordariomycetes
Sordariomycetes- morphological traits
- perithecial ascomata
- (flask-shaped with a pore that releases spores)
- form on or in a stroma - ~fusion~ between distinct gametangia
- hermaphroditic with few female traits
- “female traits”- ascogonium production
- different from mating types
Sordariomycetes- what distinguishes them from other classes?
- diverse anamorphs
- major group of plant pathogens and endophytes (economically important)
- many produce toxins, also making them economically important
how many taxonomic groupings of Sordariomycetes are we learning?
six orders within three subclasses
Gametangia of Sordariomycetes
spermatia (male gametes)
- essentially conidia on an antheridia (which is like a conidiophore)
- ASEXUAL
ascogonia or protoperithecia
- with trichogynes
- SEXUAL- occurs at the same time as asexual stages
the three major subclasses within the Sordariomycetes
Sordariomycetidae
Hypocreomycetidae
Sordariomycetidae- characteristics
- perithecial (flask-shaped) ascomata with colors that range light to dark
- Stroma producing the perithecium: small or non-existent
Four major orders of subclass Sordariomycetidae
Sordariales
Diaporthales
Ophiostomales
Magnaporthales
Sordariales characteristics
- generally saprophytic
- habitat: wood, dung, other saprophytes
- ascospores dark w appendages
- asci w distinct apical ring
Diaporthales
- plant parasites
- stromatic ascomata with long perithecial necks (unlike the rest of the groups of sordariomycetidae)
Ophiostomales
- long perithecial with long necks OR
- prototunicate asci
- associated w insects
Magnaporthales
- sexual stage almost never seen (asexual stage allows spread of disease to happen very quickly)
- infect grasses, rice, turf
- necrotrophic
- infects leaves via penetration of appresorium
- turgid pressure helps it punch thru the leaf
Name the pathogen responsible for Chestnut Blight. Provide its taxonomic grouping (order, subclass and class)
- Cryphonectria parasitica
- class sordariomycetes, subclass sordariomycetidae, order diaporthales
describe/illustrate & label the major components of the asexual and sexual stages of Cryphonectria parasitica
kills phloem cells, clogs xylem, erupts thru bark on cankers
- sexual: perithecia from stroma
- asexual: pycnidia (look very similar to perithecia but produce conidia instead of ascospores)
Describe hypovirulence and how it’s applied to Cryphonectria parasitica.
- researches found that infecting this species with a double stranded RNA virus reduces its virulence
What is anastomosis and how does it play a role in hypovirulence in Cryphonectria parasitica?
- anastomosis allows spread of disease by different strains: hyphae of different strains fuse
- anastomosis isn’t possible for all strains, only those within the same VCG, so all VCGs must be infected
Differentiate between the relationship between bark beetles & fungi, and the relationship between ambrosia beetles and fungi. Which order of fungi are most commonly associated with both of these beetles.
- both in ophistiomatales
- bark beetles spread diseases
- ambrosia beetles aid in fungus farming