Pythium monoclinum Abrinbana, Abdollahz. & Badali, 2020

Badali, Farzaneh, Abrinbana, Masoud & Abdollahzadeh, Jafar, 2020, Morphological and molecular taxonomy of Pythium monoclinum Abrinbana, Abdollahz. & Badali, sp. nov., and P. iranense, sp. nov., from Iran, Cryptogamie, Mycologie 20 (11), pp. 179-191 : 185

Pythium monoclinum Abrinbana, Abdollahz. & Badali , sp. nov.

( Fig. 5 )

MYCOBANK. — MB 823189.

TYPUS. — Iran. East Azarbaijan Province, Islami Island, from uncultivated soil; 8.V.2013; coll. F. Badali, IRAN 16695 F as dried culture in Iranian Research Institute of Plant Protection, ex-type culture (IRAN 2421 C).

ADDITIONAL SPECIMENS EXAMINED. — Iran. East Azarbaijan Province, Islami Island, from uncultivated soil; 8.V.2013; coll. F. Badali, living culture in Iranian Research Institute of Plant Protection ( IRAN 2405 C) and Westerdijk Fungal Biodiversity Institute (CBS 143584).

Iran. East Azarbaijan Province: Islami Island, from uncultivated soil; 8. V.2013; coll. F. Badali, living culture in Collection of Urmia University ( CUU 77).

ETYMOLOGY. — Name refers to the mostly monoclinous antheridia.

DESCRIPTION

Colonies

On PCA submerged with a radiate pattern and on CMA partially submerged without a special pattern. Main hyphae up to 5 µm diam.

Sporangia and zoospores

Not observed.

Hyphal swellings

Globose, occasionally subglobose, terminal or intercalary, 15-26 µm diam. (av. 21.65 µm).

Oogonia

Smooth-walled, globose, subglobose, rarely elongated, mostly terminal, occasionally subterminal or intercalary, rarely in chains, sometimes oogonial stalks consisting a swollen element below the terminal oogonia, globose oogonia 16-26 µm diam. (av. 20.94 µm), elongated oogonia up to 35 µm long.

Antheridia

1-2 per oogonium, mostly monoclinous, originating at various distances from the oogonia, occasionally arising from inflated part of oogonial stalk located immediately below oogonium, rarely diclinous, occasionally sessile, antheridial stalks mostly bending towards oogonia. Antheridial cells clavate, swollen, elongated, sometimes with constriction, 10-22 × 5-11 µm (av. 14.92 × 6.62 µm).

Oospores

Globose, subglobose, rarely peanut-shaped, plerotic, rarely aplerotic, usually one but rarely two per oogonium, globose oospores 10-24 µm diam. (av. 18.71 µm), elongated oospores up to 32 µm long, the oospore wall up to 2 µm thick.

Daily growth

On PCA 3 mm at 5°C, 6 mm at 10°C, 9 mm at 15°C, 11 mm at 20°C, 14 mm at 25°C, 10 mm at 30°C, 7 mm at 35 and 0 at 40°C. The isolates were not viable at 40°C.

NOTES

Differs from other known Pythium species by presence of globose to elongated smooth-walled oogonia, a swollen element in oogonial stalks below terminal oogonia, mostly monoclinous antheridia that occasionally arising from swollen part of oogonial stalk and their stalk mostly bending towards oogonia, (sub) globose or peanut-shaped oospores, mostly plerotic oospores and 1-2 oospores per oogonium.

Figures

FIG. 5. — Pythium monoclinum Abrinbana, Abdollahz. & Badali, sp. nov. (IRAN 16695 F, holotype): A, terminal hyphal swelling; B, intercalary hyphal swelling; C, D, monoclinous antheridia with inflated or non-inflated antheridial stalks and antheridial cells attached to oogonia; E, monoclinous antheridium originated from swollen part of oogonial stalk; F, monoclinous antheridium and intercalary oogonium with two oospores; G, intercalary oogonium provided with two onoclinous antheridia;H, diclinous antheridium and intercalary oogonium;I, sessile diclinous antheridium with constriction attached to oogonium;J, chain of ogonia and hyphal swelling; K, plerotic oospores; L, aplerotic oospore; M, peanut-shaped oospore; N, double oospore. Scale bars: A, 10 µm; B-E, 5 µm F-N, 10 µm.