IB 371 - GENERAL MYCOLOGY LECTURE 25 THURSDAY, NOVEMBER 20, 2003 LOCULOASCOMYCETES IB 371 - GENERAL MYCOLOGY LECTURE 25 THURSDAY, NOVEMBER 20, 2003

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LOCULOASCOMYCETES Luttrell (1955) - defined the Loculoascomycetes and established five orders (1973). Systematics is controversial - one (von Arx & Müller 1975) to ten (Barr 1987) orders are recognized. Group is probably not monophyletic.

LOCULOASCOMYCETES Ascoma is an ascostroma and is called a pseudothecium when it resembles a perithecium. Stroma develops before the ascogenous hyphae. Centrum with or without pseudoparaphyses at maturity. Asci are fissitunicate (bitunicate).

LOCULOASCOMYCETES Important plant pathogens Lichen associates A few human and mammal pathogens Endophytes Decomposers of wood and other plant materials

FISSITUNICATE ASCUS Consists of two clearly separate walls – an ectoacus & endoascus. At the ultra-structural level each wall may consist of more than one layer. The ectoascus is inelastic & breaks open to release the endoascus. The inner wall is elastic and may extend to great lengths. The ascospores are released through a pore at the apex of the endoascus.

FISSITUNICATE ASCUS

FISSITUNICATE ASCI endoasci endoasci

FISSITUNICATE ASCUS Relatively thin ectotunica and thicker endotunica Complete separation of the ectotunica and endotunica during ascospore discharge Ectotunica ruptures to release endotunica Nasse apical surrounding an apical or ocular chamber Banded pattern in endotunica often present Ascospores forcibly shot from endotunica

HAMATHECIUM Periphysoids - short downward growing filaments Paraphysoids - attached at both base and apex in young ascomata that become apothecioid at maturity Pseudoparaphyses - downward growing or derived from elongation of cells occupying the centrum (cellular or trabeculate)

CELLULAR PSEUDOPARAPHYSES

MYRIANGIALES Ascomata indeterminate in growth, wall consisting of pseudoparenchymatous tissue Locules are uniascal; Elsinoë type centrum Hamathecium absent Asci globose or ovoid Ascospores usually obovoid, aseptate or septate

MYRIANGIALES Epiphytic over scale insects, insect secretions, resin glands, or biotrophic or saprobic on plants Elsinoë fawcetii - citrus scab Elsinoë ampelina - grape anthracnose Elsinoë veneta - raspberry anthracnose

Grape Anthracnose

PLEOSPORALES Ascomata perithecioid, cleistotheciod, or hysterothecioid) Hamathecium of cellular pseudoparaphyses Plant parasites or decomposers More than one ascus per locule

MACROSPORA SCIRPICOLA AQUATIC PLEOSPORALES

PLEOSPORA HERBARUM

Venturia inaequalis Apple scab

MELANOMMATALES Ascomata may be perithecioid, cleistothecioid, or hysterothecioid Pseudoparaphyses are trabeculate (thin, non-septate, surrounded by gel Asci cylindric to clavate Ascospores variable Anamorphs are coelomycetous Common on dead wood

MELANOMMATALES

MELANOMMATALES pseudoparaphyses

MELANOMMATALES

DOTHIDEALES Ascomata uniloculate or multiloculate; each locule containing more than one ascus Asci usually arranged in fascicles Hamathecium absent (no physes)

DOTHIDEALES Parasitic or saprobic on plants Important plant pathogens: Mycosphaerella and Guignardia

DOTHIDEALES Mycosphaerella cercidicola - leaf spot of redbud M. fragariae - leaf spot of strawberry M. sentina - leaf spot of pear M. mycopappi - leaf spot of maple M. musicola - Sigatoka disease of bananas Guignardia bidwellii - attacks grape

From Hanlin, 1990

MYCOSPHAERELLA FRAGARIAE