title: Population genetic analysis reveals cryptic sex in the phytopathogenic fungus Alternaria alternata.
abstract: Reproductive mode can impact population genetic dynamics and evolutionary landscape of plant pathogens as well as on disease epidemiology and management. In this study, we monitored the spatial dynamics and mating type idiomorphs in ~700 Alternaria alternata isolates sampled from the main potato production areas in China to infer the mating system of potato early blight. Consistent with the expectation of asexual species, identical genotypes were recovered from different locations separated by hundreds of kilometers of geographic distance and spanned across many years. However, high genotype diversity, equal MAT1-1 and MAT1-2 frequencies within and among populations, no genetic differentiation and phylogenetic association between two mating types, combined with random association amongst neutral markers in some field populations, suggested that sexual reproduction may also play an important role in the epidemics and evolution of the pathogen in at least half of the populations assayed despite the fact that no teleomorphs have been observed yet naturally or artificially. Our results indicated that A. alternata may adopt an epidemic mode of reproduction by combining many cycles of asexual propagation with fewer cycles of sexual reproduction, facilitating its adaptation to changing environments and making the disease management on potato fields even more difficult.
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Meng
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Meng-Han
authors.initials: MH
authors.lastname: He
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: E-Jiao
authors.initials: EJ
authors.lastname: Wu
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Duan
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Ye-Kun
authors.initials: YK
authors.lastname: Xie
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Jin
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Yang
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Shang
authors.affiliation: Fujian Key Lab of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.|Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P. R. China.
authors.forename: Jiasui
authors.initials: J
authors.lastname: Zhan
mesh_terms: D000528:Alternaria / Q000145:classification / Q000235:genetics* / Q000502:physiology; D049770:Genes, Mating Type, Fungal; D014644:Genetic Variation; D005828:Genetics, Population; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012100:Reproduction, Asexual / Q000235:genetics*