title: Bacterial populations on the surfaces of organic and conventionally grown almond drupes.
abstract: OBJECTIVE
  To compare the bacterial populations on organically and conventionally grown almond drupes before and after hull split.
  
  
  RESULTS
  We constructed 16S rRNA gene libraries, containing approx. 3000 sequences each, from the bacteria from organically and conventionally grown drupes before and after hull split. We observed that before hull split both conventionally and organically grown drupes were colonized by relatively few types of bacteria that were mostly common phyllosphere-associated Proteobacteria. However, the organically grown drupes contained significantly more Alphaproteobacteria and the conventionally grown drupes contained significantly more Gammaproteobacteria. The conventionally grown drupes also contained significantly more sequences associated with the phylum Actinobacteria. After hull split, we observed a significant increase in bacterial diversity, with many newly appearing sequences that were not normally associated with the phyllosphere.
  
  
  CONCLUSIONS
  Organic and conventional growing methodologies influence the types of bacteria on almond drupes and hull split results in a burst of microbial diversification.
  
  
  CONCLUSIONS
  Production of organic produce is increasing due to consumer preferences, but it was unknown how this methodology affects the bacterial populations on almond drupes. This is the first study to compare the bacterial populations of organically and conventionally grown almond drupes.
authors.affiliation: Foodborne Toxin Detection and Protection Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, USA.
authors.forename: J A
authors.identifier: http://orcid.org/0000-0001-6877-924X
authors.initials: JA
authors.lastname: McGarvey
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Han
authors.affiliation: University of California Cooperative Extension, Oroville, CA, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Connell
authors.affiliation: Foodborne Toxin Detection and Protection Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Stanker
authors.affiliation: Foodborne Toxin Detection and Protection Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hnasko
mesh_terms: D000383:Agriculture / Q000379:methods*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D020563:Gammaproteobacteria / Q000235:genetics; D015723:Gene Library; D008969:Molecular Sequence Data; D000068181:Prunus dulcis / Q000254:growth & development / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: agriculture; almond; environmental; microbial phylogenetics; microbial structure