Phytophthora alpina Bregant, Montecchio and Linaldeddu (2020)

Bregant C, Sanna GP, Bottos A, Maddau L, Montecchio L, Linaldeddu BT. 2020. Diversity and pathogenicity of Phytophthora species associated with declining alder trees in Italy and description of Phytophthora alpina sp. nov. Forests 11 (8): 848.

Mycobank

MB836109

Etymology

refers to the alpine environment where the species was originally found

Typification

Type: ITALY: Vigo di Cadore, isolated from rhizosphere of a declining green alder tree, 14 October 2019, collected by Carlo Bregant, holotype CBS H-24392, a dried culture on CA

Ex-type: culture OV3 = CBS 146801

Sequences for ex-type in original manuscript:  ITS MT707332, cox1 MT729668, β-tubulin MT729673

Position in ITS phylogenetic tree

Clade 1a

Colonies and cardinal temperatures

Colony morphology stellate on PDA and MEA, uniform on CA. Minimum growth temperature 2°C, optimum 20°C, and maximum 35°C.

Conditions for growth and sporulation

Sporangia produced in non-sterile pond water after 24–36 hours. Oogonia are formed in single culture on CA after 10–20 days.

Asexual phase

Sporangia were papillate, caducous and predominantly globose to ovoid in shape. Sporangia averaged 33 x 27 µm (overall range 18 – 54 x 14 – 39 µm); Sporangiophores simple or loose sympodia. Hyphal swellings present. Chlamydospores present.

Sexual phase

Heterothallic. Oogonia smooth-walled, average 31 µm. Oospores aplerotic, averaged 26 µm. Antheridia both paragynous and amphigynous

Most typical characters

Morphologically similar to other species in Clade 1a especially P. cactorum.

Additional specimen(s) evaluated

ITALY: Vigo di Cadore, isolated from a bleeding canker on green alder, 26 May 2020, collected by Carlo Bregant, culture OV23

Distribution: Italy
Substrate: roots and trunk
Disease note: bleeding cankers and rhizosphere of declining green alder trees in Italy
Host: Alnus viridis

none available

Fact sheet author

Treena Burgess, Ph.D., Phytophthora Science and Management, Harry Butler Institute, Murdoch University