Fungi
Passionfruit powdery mildew
Oidium passiflorae J. Politis Ascomycetes, Erysiphales
Status
Exotic (but present in Australia)

 

 

fructifications-LM

Caption: Oidium passiflorae on Passiflora foetida (VPRI 20581). (a-c) Lobed or hooked mycelial appressorium (arrow). (d-f) Conidiophores and lobed mycelial appressorium (arrow). (g-k) conidiophores. (l) conidium. (m-s) Germinated conidium. (Bar = 10 µm).
Source: Liberato (2006) DPI&F

The fungus: On living leaves. Mycelium epiphyllous. Hyphae branched, septate, sub-straight to flexuous, hyaline, cells 30―68 × 4―6 μm, mycelial appressoria multilobed, individually or in pairs. Conidiophores produced from the external mycelium, hyaline, smooth, septate, foot-cells usually straight, 16―60 × 5―8 μm, followed by (0―) 1―2 cells. The second cell of conidiophore is 10―40 × 6―10 μm and they are usually wider than the foot-cell. Conidia produced singly at the apex of the conidiophores, cylindrical or doliiform, 24―44 × 10―17 μm, l/w ratio 1.5―3.5, hyaline, smooth. Germ tube, one at shoulder of the conidium, rarely two, small (up to 1 × the length of the conidium), ending in a lobed or apically swollen appressorium. Teleomorph: unknown (Liberato 2006).

Note: Braun (1998) reported hyphal cells 2.5―5 μm wide, foot-cells 15-50 x 4-10 μm and conidia 25-55 x 10-18 μm.