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Poster: Biology & Disease Mgmt: Biological Control


Linking microbial taxa in SDS-suppressive soils of Soybean fields
A. SROUR (1), A. Fakhoury (1), J. Bond (2), L. Leonardo (3), D. Malvick (4) (1) Southern Illinois University, U.S.A.; (2) Southern Illinois University, U.S.A.; (3) Iowa state University, U.S.A.; (4) Univesrity of Minnesota, U.S.A.

Sudden Death Syndrome (SDS) is one of the most important diseases of soybean in the Midwest. SDS is caused by the soilborne fungus Fusarium virguliforme. SDS frequently appears in circular to oblong patches in a soybean field and are often found unevenly distributed across the same field, while conditions in the rest of the field may appear to be naturally suppressive to the disease. In the SDS-suppressive areas, soybean plants may be less affected by the pathogen because of the activity of other soil microbes. There is a lack of comprehensive studies that investigate the role of soil inhabiting bacteria and fungi in affecting the development of the SDS. By coupling metabarcoding with paired-end Illumina MiSeq sequencing, we identified key microbial taxa involved in the suppression or promotion of the SDS pathogen. Statistical analyses revealed significant differences in fungal and bacterial community composition between suppressive and conducive soils. A microbial consortia involving members of Actinobacteria, Fusarium oxysporum, Trichoderma, Penicillium, Metacordycpes,and Purpureocillium were found consistently associated with SDS suppression. In contrast, members of the Fusarium solani sp. complex were frequently present in conducive soils.