title: Characterization of antibiosis and antixenosis to the woolly poplar aphid (Hemiptera: Aphididae) in the bark of different poplar genotypes.
abstract: The woolly poplar aphid, Phloeomyzus passerinii (Signoret) (Hemiptera: Aphididae), is a major pest of poplar plantations in the Mediterranean basin and the Near East. Aphids colonize poplar trunks and feed upon the cortical parenchyma. Despite the economic importance of poplar, little is known about the mechanisms involved in poplar resistance to this pest. However, Populus x canadensis Moench genotypes show various levels of resistance to P. passerinii. This study has investigated the type of poplar resistance (antibiosis or antixenosis) by assessing aphid settlement, physiology (survival, development, and reproduction), and stylet penetration behavior (electrical penetration graph) on three P. x canadensis genotypes; '1214' (susceptible), 'Brenta' (resistant), and '145/51' (intermediate). Because settlement was reduced, the highly resistant genotype Brenta exhibited surface antixenosis. In addition, nymphal survival was null on Brenta, and twice less adult aphid initiated a sustained intracellular phase in the cortical parenchyma of that genotype compared with the other two genotypes. Thus, Brenta also showed parenchyma-located antixenosis coupled with antibiosis characteristic. In contrast, P. passerinii had no difficulty to initiate a sustained ingestion in the cortical parenchyma of the intermediate genotype 145/51, but decreased fecundity and lower intrinsic rate of natural increase were clear expressions of antibiosis.
authors: UPRES EA 1207, Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, Rue de Chartres, BP 6759, FR-45067 Orleans Cedex, France.
authors: Sophie
authors: S
authors: Pointeau
authors: Arnaud
authors: A
authors: Ameline
authors: Aurélien
authors: A
authors: Sallé
authors: Stéphanie
authors: S
authors: Bankhead-Dronnet
authors: François
authors: F
authors: Lieutier
mesh_terms: D000818:Animals; D000898:Antibiosis; D001042:Aphids / Q000502:physiology*; D005260:Female; D005838:Genotype; D006790:Host-Parasite Interactions; D009758:Nymph / Q000254:growth & development; D024301:Plant Bark / Q000469:parasitology; D032107:Populus / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D012098:Reproduction