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Oral: Population Dynamics


Species diversity and population structure of Pythium and Globisporangium in Long Island, NY ornamental greenhouses in 2014
M. Proano (1), C. Ayala (2), A. Chiriboga (2), M. Daughtrey (3), C. Garzon (4), S. Marek (1), H. Melouk (1), S. Marek (4) (1) OKLAHOMA STATE UNIVERSITY, U.S.A.; (2) Universidad de las Fuerzas Armadas ESPE, Sangolquí, Ecuador, Ecuador; (3) Cornell Universi

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Globisporangium and Pythium are plant pathogens that cause root rots, blackleg of cuttings, and damping off of various crops. Growth of the nursery and floriculture production industries, one of the fastest growing agricultural sectors in the United States, has contributed to the increase of the economic impact of ornamental plant diseases. Seasonal assessment of the diversity of species causing Pythium diseases on three ornamental greenhouses from Long Island, NY is providing information about the temporal dynamics of Pythium and Globisporangiumspecies in these agricultural systems. DNA sequences of the ITS region were obtained to confirm the identity of 207 isolates collected seasonally from three ornamental operations in 2014. As in previous years, G. irregularesensu lato was the predominant pathogen isolated (n=126). Simple sequence repeats (SSRs) were used to characterize the structure of G. irregulare s.l. populations. PCoA of ten SSR loci defined four groups based on genetic distances. AMOVA revealed significant genetic differentiation between greenhouse populations and between genetic lineages. The main lineage included most of the isolates present in two greenhouses, which suggest a potential common source of inoculum for those facilities.