Penicillium spp. (fruit rots)

Several species of Penicillium * are reported on tomato fruits, causing damage both during cultivation and after harvest ( P. expansum Link, P. citrinum Thom, P. notatum Westling, P. brevi-compactum Dierckx, P. cyaneo-fulvum Biourge, P. cyclopium West., P. puberulum Bainier, P. italicum Wehmer ). They are responsible for soft, moist and dark lesions, which can develop either from the area of ​​implantation of the peduncle (Figures 1 to 3) or elsewhere on the fruit, at the level of a wound. The injured tissues are gradually covered with spore-bearing pads, the color of which may vary depending on the species present and the degree of development of the fruiting bodies (blue, gray, green ).

As an example, we will only describe P. expansum , which is the species most often observed on many fruits (apple, pear, kiwi, orange, tangerine, grapefruit, strawberry ) and on various vegetables such as l garlic or onion. Like many other Penicillium , it is naturally present in the soil and certainly on the various organs of the tomato. It is preserved there in its mycelial form or in the state of spores. The latter, very light and mass produced, are carried by the air until they fall on the surface of a fruit near a wound. They then germinate, and the mycelium grows very extensively, growing in all directions inside the flesh which is gradually broken down thanks to several enzymes. The fungus does not take long to sporulate; conidiophores develop generating conidia (Figures 4 and 5). The number of spores on the surface of a contaminated fruit can run into the millions. As soon as they reach maturity, they separate easily and float in the air for some time before falling back and causing new contamination. Germination is optimal in a humid atmosphere between 20 and 25 ° C, and the growth of the mycelium stops above 30 ° C. It should be noted that P. expansum only attacks revolving or ripe fruits and that it synthesizes two toxins: patulin, a mycotoxin quite common in animal feed, and citrinin.

Generic protection methods are available at the following link .

* Anamorpha of Eupenicillium .
  Classification :  Fungi, Ascomycota, Pezizomycotina, Eurotiomycetes, Eurotiomycetidae, Eurotiales, Trichocomaceae