Identification of Penicillium species from citrus fruits and various bread types in Shiraz

Members belonging to the genus Penicillium have a worldwide distribution and to date contains 359 accepted species divided among 25 sections, some of which have a considerable economic effect. The most important foodstuff which is the ecological nich of species of this genus are bread, as microbial decay agents, and citrus fruits, as postharvest pathogens. In this study, during winter 2018, spring and autumn 2019, samples were collected from infected citrus fruit (orange, tangerine, sour orange, lemon, lemon thistle, Key lime, bergamot, grapefruit, bael and kumquat) and various types of infested wheat bread. Species were identified based on morphological characteristics including microscopic (i.e. conidia dimensions, conidial ornamentation, phialide and metulae length, conidiophore width and ornamentation, and conidiophore branching pattern) as well as macroscopic features (including growth rate, obverse and reverse color of the colony, colony texture, and sporulation rate). Ten species were identified according to morphological features. Four species, including Penicillium italicum, P. ulaiense, P. digitatum and P. discolor, belonging to sections Penicillium, Digitata and Viridicata, were identified on citrus fruits and six species, including P. chrysogenum, P. atramentosum, P. polonicum, P. roqueforti, P. citrinumand P. oxalicum, belonging to sections Chrysogena, Viridicata, Roqueforti, Citrina and Lanata-Divaricata, were characterized from infested bread. Penicillium ulaiense and P. atramentosum , are new for Iran mycobiota and it is the first world report of P. discolor as a citrus pathogen.