title: Ecotypes of the model legume Lotus japonicus vary in their interaction phenotypes with the root-knot nematode Meloidogyne incognita.
abstract: OBJECTIVE
  Knowledge of host factors affecting plant-nematode interactions is scarce. Here, relevant interaction phenotypes between a nodulating model host, Lotus japonicus, and the endoparasitic root-knot nematode Meloidogyne incognita are assessed via a genetic screen.
  
  
  METHODS
  Within an alpha experimental design, 4-week-old replicate plants from 60 L. japonicus ecotypes were inoculated with 1000 nematodes from a single egg mass population, and evaluated for galling and nematode egg masses 6 weeks after inoculation.
  
  
  RESULTS
  Statistical analysis of data for 57 ecotypes showed that ecotype susceptibilities ranged from 3.5 to 406 galls per root, and correlated strongly (r = 0.8, P < 0.001, log scale) with nematode reproduction (ranging from 0.6 to 34.5 egg masses per root). Some ecotypes, however, showed a significant discrepancy between disease severity and nematode reproduction. Necrosis and developmental malformations were observed in other infected ecotypes.
  
  
  CONCLUSIONS
  The first evidence is provided of significant variability in the interactions between L. japonicus and root-knot nematodes that may have further implications for the genetic dissection and characterization of host pathways involved in nematode parasitism and, possibly, in microbial symbiosis.
authors.affiliation: Plant-Pathogen Interactions Division, Rothamsted Research, Harpenden AL5 2JQ, UK. hector.cabrera@bbsrc.ac.uk
authors.forename: H L Cabrera
authors.initials: HL
authors.lastname: Poch
authors.forename: R H Manzanilla
authors.initials: RH
authors.lastname: López
authors.forename: S J
authors.initials: SJ
authors.lastname: Clark
mesh_terms: D000818:Animals; D006790:Host-Parasite Interactions / Q000502:physiology; D000070116:Lotus / Q000145:classification / Q000254:growth & development* / Q000469:parasitology; D009348:Nematoda / Q000254:growth & development*; D010935:Plant Diseases / Q000469:parasitology; D018517:Plant Roots / Q000254:growth & development* / Q000469:parasitology; D013045:Species Specificity