title: Eelgrass slabs, a soilless culture substrate that inhibits adhesion of fungi and oomycetes and enhances antioxidant activity in tomato.
abstract: Composed of a marine plant,  Zostera  sp., eelgrass slabs are a novel organic substrate for soilless cultures used in tomato production. The benefit of using eelgrass slabs for growing tomatoes was assessed by comparing it with coconut fiber slabs in regard to contamination by  Pythium  spp. and to the antioxidant properties of tomato fruits. First, tomato root contamination by Pythium spp. was studied by direct plate counting, and a molecular comparison of fungal and oomycete communities was conducted using PCR-DHPLC. Second, the antioxidant properties of tomato fruits were analyzed by measuring total phenol and carotenoid contents and by evaluating radical scavenging activity. Compared to plants grown on coconut fiber slabs, those on eelgrass slabs presented a lower rate of Pythium spp. root contamination. Moreover, culture on eelgrass slabs produced fruits with better radical scavenging activity and higher total phenol content compared to controls. Carotenoid content was not affected by the type of substrate. This study highlights the value of detrital leaves of Zostera sp. as a substrate for soilless culture that reduces root contamination and also promotes the production of tomato fruits with better nutritional value.
authors.affiliation: Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, EA 3882, IFR148 ScInBioS, ESMISAB, Technopôle Brest-Iroise, 29280 Plouzané, France. laetitia.duros@gmail.com
authors.forename: Laetitia
authors.initials: L
authors.lastname: Meot-Duros
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Le Floch
authors.forename: Benoit
authors.initials: B
authors.lastname: Meot
authors.forename: Patricia
authors.initials: P
authors.lastname: Letousey
authors.forename: Bruno
authors.initials: B
authors.lastname: Jacob
authors.forename: Georges
authors.initials: G
authors.lastname: Barbier
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D002338:Carotenoids / Q000032:analysis; D003059:Cocos; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development*; D005658:Fungi; D018551:Solanum lycopersicum / Q000254:growth & development* / Q000382:microbiology* / Q000469:parasitology; D010636:Phenols / Q000032:analysis; D018517:Plant Roots / Q000382:microbiology / Q000469:parasitology; D011775:Pythium; D035962:Zosteraceae
chemical_list: D000975:Antioxidants; D010636:Phenols; D002338:Carotenoids