Didymella macrostoma (Mont.) Q. Chen & L. Cai 2015

Brien (1934) described this fungus from apple fruit held in cold store in New Zealand. Ainsworth and Bisby (1961) stated that the genus Polyopeus Horne is synonymous with Phoma. Unfortunately no herbarium material was kept from Brien's studies. In recent researches on apple fruit rots (Brook 1960; Cooper and Padfield, 1965) it has not been recorded. It is suggested that the name in New Zealand could have been confused with the Phomopsis stage of Diaporthe perniciosa.

Gadgil, P.D. (in association with Dick, M.A.; Hood, I.A.; Pennycook, S.R.) 2005: Fungi on trees and shrubs in New Zealand. Fungi of New Zealand. 4. Fungal Diversity Press.

Phoma macrostoma Mont. 1849

Description

Type: Foliicolous Fungi; Description: Conidiomata pycnidial, scattered to gregarious, immersed to superficial, globose to subglobose, rusty brown to black, 0.1–0.3 mm in diameter, with a distinct large (10–30 μm in diameter) ostiole; on leaf spots or on necrotic tissue of other plant parts. Conidia ellipsoid to oval, 0-septate (rarely 1-septate), 4–8 × 2–4 μm, smooth, hyaline.

Distribution

Distribution: Northland, Auckland, Bay of Plenty, Wanganui.; 1st Record: Cunningham (1921: as Phoma pomi).

Notes

Pathogenicity

Significance: Causes a leaf spot of minor importance in Eriobotrya japonica (loquat) and spotting of apples (Dingley 1969).; Host(s): Actinidia deliciosa, Eriobotrya japonica, Magnolia sp., Malus ×domestica.

Johnston, P.R. 1981: Phoma on New Zealand grasses and pasture legumes. New Zealand Journal of Botany 19(2): 173-186.

Phoma macrostoma var. incolorata (A.S. Horne) Boerema & Dorenb. 1970

Collections Examined

REPRESENTATIVE CULTURES: PDDCC 6628, 6629, 6814.

Description

COLONY MORPHOLOGY OA: Colonies 40-70 mm diam. after 7 days. Mycelium; sparse, cottony or stringy, white to pale grey; numerous pycnidia with orange conidial ooze scattered over colony surface and often forming a densely aggregated band half-way between centre and edge of colony. Reverse; pale grey or colourless. ME: Colonies 30-60 mm. Mycelium; sparse, white to pale grey or pale olivaceous, pycnidia scattered, over whole colony, often with a more closely grouped band at the colony edge. Reverse; colourless, pale olivaceous or yellow, pycnidia showing through as dark spots or as orange spots if oozing conidia. CHLAMYDOSPORES: None. CONIDIA: Variable in size and shape, occasionally 1-septate. (5-)6-8(-11) x (2-)2.5-3.5(-4) µm. PYCNIDIA: Often with several ostioles, solitary or aggregated into groups with adjacent pycnidia having confluent walls.

Habitat

OCCURRENCE: Common and plurivorous. Saprophyte or weak wound parasite.

Johnston, P.R. 1981: Phoma on New Zealand grasses and pasture legumes. New Zealand Journal of Botany 19(2): 173-186.

Phoma macrostoma Mont. 1849 var. macrostoma

Collections Examined

REPRESENTATIVE CULTURES: PDDCC 6603, 6803.

Description

COLONY MORPHOLOGY OA: Colonies 50-70 mm diam. after 7 days. Mycelium; cottony to stringy, white or olivaceous with a red tinge. Numerous pycnidia on agar surface, often with buff coloured conidial slime. Reverse; bright yellow or red. ME: Colonies 40-50 mm. Mycelium; cottony, grey, olivaceous, or reddish; concentric bands of pycnidia forming at edge of colony. Reverse; rust coloured. CHLAMYDOSPORES: None. CONIDIA: Variable in shape, often irregular, occasionally 1-septate. (4.5-)6-9(-12) x (2-)2.5-3.5(-4) µm. PYCNIDIA- Often with several ostioles, solitary or aggregated into groups of 5-10 with adjacent pycnidia having confluent walls.

Habitat

OCCURRENCE: Plurivorous saprophyte or weak wound parasite, more commonly found on woody plants.

Taxonomic concepts

Name

Cited name

Reference

Preferred name

Parent name

Didymella macrostoma (Mont.) Q. Chen & L. Cai 2015

Didymella macrostoma (Mont.) Q. Chen & L. Cai 2015

Chen, Q.; Jiang, J.R. et al. (2015)

Didymella macrostoma (Mont.) Q. Chen & L. Cai 2015