title: Mushroom tumor: a new disease on Flammulina velutipes caused by Ochrobactrum pseudogrignonense.
abstract: Mushroom tumor on Flammulina velutipes has become the main disease during the off-season cultivation of F. velutipes while the causal organism has remained unknown. The present study was aimed at identifying the pathogen confirming its pathogenisity following Koch's Postulates, characterizing it using morphological, physiological, biochemical and molecular features, and studying its current distribution. We determined that mushroom tumor is a new bacterial infection disease caused by Ochrobactrum pseudogrignonense. It produces tumor-like structures on the surface of the substrate, and inhibits the formation of primordia and fruiting of F. velutipes. The molecular studies showed that this new pathogen is closely related to Ochrobactrum based on 16S rRNA sequences. This is the first time that Ochrobactrum has been shown to be a pathogen of a mushroom.
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China Scientific Observing and Experimental Station of Southwestern Region Agromicrobiological Resource Utilization, Ministry of Agriculture, Chengdu 610066, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China Scientific Observing and Experimental Station of Southwestern Region Agromicrobiological Resource Utilization, Ministry of Agriculture, Chengdu 610066, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Peng
authors.affiliation: Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China Scientific Observing and Experimental Station of Southwestern Region Agromicrobiological Resource Utilization, Ministry of Agriculture, Chengdu 610066, China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: He
authors.affiliation: Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China Scientific Observing and Experimental Station of Southwestern Region Agromicrobiological Resource Utilization, Ministry of Agriculture, Chengdu 610066, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China Scientific Observing and Experimental Station of Southwestern Region Agromicrobiological Resource Utilization, Ministry of Agriculture, Chengdu 610066, China.
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Gan
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China zhangxiaopingphd@126.com.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhang
mesh_terms: D055393:Flammulina / Q000737:chemistry / Q000254:growth & development*; D008969:Molecular Sequence Data; D042041:Ochrobactrum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D010802:Phylogeny; D010941:Plant Tumors / Q000382:microbiology*; D014675:Vegetables / Q000382:microbiology*
keywords: bacterial pathogen; off-season cultivation; southwest China; winter mushroom