Penicillium expansum

Penicillium expansum spores on a pear

Penicillium expansum is a mold, which often causes fungal diseases of fruits such as apples and grapes.

Features

Features on culture media

On Czapek agar, a special culture medium, the fungus grows very rapidly and forms flaky, tufted to pin-shaped ( synnematale ) colonies. The back appears cream color to yellow with a brown center, but can also be orange to dark brown. From yeast extract agar they are on the back of creamy yellow to orange. The Konidienmasse is dull green. It is formed a soluble brown pigment. They do not grow at 37 ° C. The colony respond to the Ehrlich reagent strong violet.

Microscopic characteristics

The conidiophores are smooth-walled and 200-500 microns long and dreiwirtelig branched. Metulae cylindrical, so the Hyphenast from which the cells are caused kondienbildenden 12-18 microns long. The cylindrical phialides are also close together, bottle-shaped with a short narrow neck and 8-11 microns long. The conidia are elliptical, smooth, and measure 3-3.5 x 2.5-3 microns

Damage

Infected fruits are covered with a greenish or coffee-colored coating of mold. Especially often comes Penicillium expansum ago in grapes. Come for the wine produced from it on rough off-flavors, such as mold, bitter or Mufftöne. When he calls apple during storage produced the so-called blue mold and produces the toxin patulin.

Ecology and distribution

The infection is spread via air spores. The fungi feed on dead organic material. Important for the spread of infection, the moisture and the sugar on the surface of Frucht.Insbesondere are in orchards and vineyards Penicillium expansum can lead to major crop failure, as it can quickly infect large parts of the plantations with the help of insects. As Sekundärfäuleerreger it infects mainly berries, which are already affected by gray mold (Botrytis cinerea). Also by wasps feeding and hailstorms or other mechanical damage an infection is possible. Through cracks and injuries to the fruits of the fungus penetrates the cells.

It is mainly used on pome fruit such as apple, pear before, but also on cherries, plums and other stone fruits, also on tomatoes, papaya, Albizia gummifera, quince, yam, walnut and many other fruits and plants in front. It is distributed almost worldwide, in Europe, Africa, North America, Australia, Japan and Israel.

Combat

In general, the active fighting the mushrooms in the wild is not possible. The infected fruit should be removed immediately so that they can not serve as a source of further infection.

All measures to prevent rot and injury to grapes, are useful. The most important preventive measure is the avoidance of wounds.

Pathogenicity in humans

For the people of the fungal pathogen classified as not ( danger level BSL -1). But in a few cases it caused keratitis. But Dangerous is the toxin patulin produced by him.