|SHARMA-POUDYAL, DIPAK - Oregon Department Of Agriculture|
|YIN, CHUNTAO - Washington State University|
|HULBERT, SCOT - Washington State University|
Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2017
Publication Date: 10/3/2017
Citation: Sharma-Poudyal, D., Schlatter, D.C., Yin, C., Hulbert, S., Paulitz, T.C. 2017. Long-term no-Till: A major driver of fungal communities in dryland wheat cropping systems. PLoS One. https://doi.org/10.1371/journal.pone.0184611.
Interpretive Summary: We investigated impact of no till vs conventional tillage on fungal communities, in long-term comparison sites in Washington and Idaho over 3 year. We found that in 2 of 3 location, the number of fungal species were greater in no-till. In no-till, there was a greater abundance of Humicola nigrescens, Cryptococcus terreus, Exophiala sp.,Cadophora sp. Hydnodontaceae spp., and Exophiala sp. In conventional tillage, there was a greater abundance of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum. The weak pathogen Microdochium bolleyi was more abundant in no-till. We suspect that no-till fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. Conventional tillage fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia.
Technical Abstract: In the dryland Pacific Northwest wheat cropping systems, no-till is becoming more prevalent as a way to reduce soil erosion and fuel inputs. Tillage can have a profound effect on microbial communities and soilborne fungal pathogens, such as Rhizoctonia. We compared the fungal communities in long-term no-till (NT) plots adjacent to conventionally tilled (CT) plots, over three years at two locations in Washington and one location in Idaho. We used pyrosequencing of the fungal ITS gene. We identified 422 OTUs after rarefication. Fungal richness was higher in NT compared to CT, in two of the locations. Humicola nigrescens, Cryptococcus terreus, Exophiala sp.,Cadophora sp. Hydnodontaceae spp., and Exophiala sp. were more abundant in NT, while species of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum were more abundant in CT in most locations. Other abundant groups that did not show any trends were Fusarium, Mortierella, Penicillium, Aspergillus and Macroventuria. Plant pathogens such as Rhizoctonia (Ceratobasidiaceae) were not abundant enough to see tillage differences, but Microdochium bolleyi, a weak root pathogen, was more abundant in NT. We hypothesize that NT fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. CT fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia. But a larger proportion of the fungal community are not affected by tillage and may be niche generalists.