Surrounded: Inoculum Sources of <i>Colletotrichum gloeosporioides</i> Complex Pathogens Around Florida Ericales Crops: Tea, Camellia, and Blueberry

Tea, <i>Camellia sinensis</i>, is a globally important crop plant that is currently under investigation for production in the Southeastern United States. Both in the United States and in traditional tea production regions, one of the most damaging diseases of tea is anthracnose, or brown blight, caused by various species of <i>Colletotrichum</i>. In the United States, only a single species had previously been reported on tea, whereas at least 12 species are known to cause disease in other regions, raising the question: Is the absence of additional species in U.S.-grown tea caused by differences between U.S. and Asian pathogen populations, or simply due to the limited acreage and duration of tea production in North America? We conducted a survey of <i>Colletotrichum</i> spp. in tea, in targeted plants likely to share pathogens with tea (ornamental camellias and blueberry), and in weeds around all three target hosts and conducted subsequent pathogenicity tests with representative isolates on tea. We identified 22 new host-fungus combinations for <i>Colletotrichum</i> species in the United States, 21 of which are also first reports globally. Further, we confirmed a second species of <i>Colletotrichum</i> causing anthracnose on tea in the United States, isolated <i>Colletotrichum camelliae</i> from multiple unrelated hosts, and demonstrated that isolates of both species recovered from other hosts are capable of causing disease on tea.