Fungi from Malus in Qujing, China: two new species, three new records, and insights into potential host jumping and lifestyle switching

Apple trees [<i>Malus domestica</i> Borkh. (<i>Rosaceae</i>)] are one of the important temperate fruit crops in China. In comparison to other temperate fruits, such as grapes and pears, fungal studies (in Yunnan) associated with <i>M. domestica</i> are fewer in number. In the present study, we investigated fungi associated with <i>M. domestica</i> in Qujing City, Yunnan Province, China. Samples were collected from apple gardens in different locations. Single spore isolation was carried out to isolate saprobic fungi, while the surface sterilization method was carried out to isolate endophytic fungi. Molecular analyses were carried out to determine the phylogenetic placement of the new collections. Based on the combined methods of morphology and phylogeny, <i>Cytospora qujingensis</i> sp. nov. and <i>Hypoxylon malongense</i> sp. nov. are introduced as novel saprobic and endophytic taxa, respectively. Moreover, <i>Aureobasidium pullulans</i> and <i>Cytospora schulzeri</i> are reported as new geological records from southwestern China. <i>Allocryptovalsa castaneae</i> is reported on <i>M. domestica</i> in China for the first time. The checklist of fungi associated with <i>M. domestica</i> in China is presented.