title: Molecular diversity of arbuscular mycorrhizal fungi in onion roots from organic and conventional farming systems in the Netherlands.
abstract: Diversity and colonization levels of naturally occurring arbuscular mycorrhizal fungi (AMF) in onion roots were studied to compare organic and conventional farming systems in the Netherlands. In 2004, 20 onion fields were sampled in a balanced survey between farming systems and between two regions, namely, Zeeland and Flevoland. In 2005, nine conventional and ten organic fields were additionally surveyed in Flevoland. AMF phylotypes were identified by rDNA sequencing. All plants were colonized, with 60% for arbuscular colonization and 84% for hyphal colonization as grand means. In Zeeland, onion roots from organic fields had higher fractional colonization levels than those from conventional fields. Onion yields in conventional farming were positively correlated with colonization level. Overall, 14 AMF phylotypes were identified. The number of phylotypes per field ranged from one to six. Two phylotypes associated with the Glomus mosseae-coronatum and the G. caledonium-geosporum species complexes were the most abundant, whereas other phylotypes were infrequently found. Organic and conventional farming systems had similar number of phylotypes per field and Shannon diversity indices. A few organic and conventional fields had larger number of phylotypes, including phylotypes associated with the genera Glomus-B, Archaeospora, and Paraglomus. This suggests that farming systems as such did not influence AMF diversity, but rather specific environmental conditions or agricultural practices.
authors.affiliation: Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA, Wageningen, The Netherlands. horticrs@fagro.edu.uy.|Dept. Producción Vegetal, CRS, Facultad de Agronomía, Universidad de la República, Progreso, Uruguay. horticrs@fagro.edu.uy.
authors.forename: Guillermo A
authors.initials: GA
authors.lastname: Galván
authors.affiliation: Mushroom Section of Applied Plant Research, Plant Research International, Wageningen University and Research Centre, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.|Department of Plant Physiology and Molecular Plant Biology, Eötvös Loránd University, P.O. Box 120, H-1518, Budapest, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Parádi
authors.affiliation: Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Karin
authors.initials: K
authors.lastname: Burger
authors.affiliation: Mushroom Section of Applied Plant Research, Plant Research International, Wageningen University and Research Centre, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.|Knowledge Centre Triple E, Sweerts de Landasstraat 46, 6814 DG, Arnhem, The Netherlands.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Baar
authors.affiliation: Department of Soil Quality, Wageningen University and Research Center, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kuyper
authors.affiliation: Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Scholten
authors.affiliation: Plant Research International, Wageningen University and Research Center, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.|Centre for Genetic Resources (CGN), Wageningen University and Research Centre, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
authors.forename: Chris
authors.initials: C
authors.lastname: Kik
mesh_terms: D000383:Agriculture / Q000379:methods; D044822:Biodiversity; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D055137:Glomeromycota / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D038821:Mycorrhizae / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D009426:Netherlands; D019697:Onions / Q000382:microbiology*; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D012988:Soil Microbiology
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal