Delimiting cryptic pathogen species causing apple Valsa canker with multilocus data

• DOI: 10.1002/ece3.1030
• Publication Date: 2014-03-19T05:42:46Z
• Authors: Xuli Wang; Rui Zang; Zhiyuan Yin; Zhensheng Kang; Lili Huang
• Keywords: Canker; Coalescent theory

Abstract Fungal diseases are posing tremendous threats to global economy and food safety. Among them, Valsa canker, caused by fungi of their Cytospora anamorphs, has been a serious threat fruit forest trees is one the most destructive apple in East Asia, particularly. Accurate robust delimitation pathogen species not only essential for development effective disease control programs, but also will advance our understanding emergence plant diseases. However, especially difficult because high variability morphological traits many cases lack teleomorph. In this study, we delimitated boundary pathogens causing canker with multifaceted approach. Based on three independent loci, internal transcribed spacer ( ITS ), β ‐tubulin (Btu), translation elongation factor‐1 alpha EF 1 α inferred gene both maximum likelihood Bayesian methods, estimated tree multispecies coalescent approaches, validated delimitation. Through divergence time estimation ancestral host reconstruction, tested possible underlying mechanisms fungal speciation host‐range change. Our results proved that two varieties former V. mali represented distinct species, pyri , which diverged about 5 million years ago, much later than preferred hosts, excluding scenario fungi–host co‐speciation. The marked different thermal preferences contrasting pathogenicity cross‐inoculation suggest ecological divergences between species. Apple was likely . Host‐range expansion led occurrence pear apple. represent an example data might underestimate diversity.