Genus/species(alias): Coniella petrakii (White rot)
Classification: Ascomycete
Morphology:
- Cell/Zygote: Pycnidia globose and slightly depressed to subglobose, in some cases tapering slightly towards the ostiole, 200–350 μm wide, smooth, initially hyaline with a dark central conidial mass, becoming dark brown, ostiole central, up to 100 μm wide, with cells darker brown around the ostiole; wall 15–25 μm thick, consisting of 3–5 layers of medium browntextura angularis; pycnidia containing a basal, central cushion of hyaline cells that give rise to conidiophores.
- Colony: PDA in 90 mm Petri dishes and incubated in the dark for 7 days: colonies flat, buff colored on surface, and honey in reverse, reaching 36 mm after 7 d at 25°C
- Spore: hyaline when immature, becoming pale to medium brown, inequilateral, smooth, frequently with a hyaline, lateral appendage, narrowly ellipsoidal, apices tapering, subobtusely rounded, bases subtruncate, multiguttulate, straight to slightly curved, wall of medium thickness
- Ascus: dense, slender, simple or branched below, 0–3-septate, surrounded by a mucous coating
- Liquid Growth: (ie dispersed, pellicle, film, clumpy) unknown
- Physiological Traits: 3 – 8 day incubation period after infection, (growth substrates, end products) unknown
Ecological Traits:
Soil borne fungi, need warm temperature and simultaneous wetness on the berry or rootstock surface to infect, masses of pycnidia forming pycnospores arise from the berry surface and overwinter on the ground.
Distinguishing Features:
Causes white rot, damaged rootstocks will show brown spots, infected berries become yellowish, shrink, and have brown pustules, the pustules cause the cuticle to detach from the epidermis.
Role in wine:
Causes white rot in the vineyard, which leads to infected berries that need to be removed before entering the winery
Sensitivities:
- SO2: Unknown
- Sorbate: Unknown
- DMDC: Unknown
- pH: Unknown
- Acids: Unknown
- Ethanol: Unknown
- Anaerobiosis: Unknown
- Heat: 35°C