Wild Solanum Resistance to Aphids: Antixenosis or Antibiosis?

• Published in: Journal of economic entomology 2008-04, Vol.101 (2), p.584-591
• Main Authors: Le Roux, Vincent, Dugravot, Sébastien, Campan, Erick, Dubois, Françoise, Vincent, Charles, Giordanengo, Philippe
• Format: Article
• Language: English
• Subjects: Animals; antibiosis; antixenosis; Aphids - physiology; Biological and medical sciences; Control; electrical penetration graph; electrical penetration graph technique; feeding behavior; Fundamental and applied biological sciences. Psychology; Generalities; Host-Parasite Interactions; ingestion; leaf age; leaves; Life Sciences; Macrosiphum euphorbiae; Myzus persicae; Nymph; olfactometry; pest resistance; phloem; phloem ingestion; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - immunology; Plant Leaves - parasitology; PLANT RESISTANCE; potatoes; Protozoa. Invertebrates; resistance mechanisms; salivation; Solanum; Solanum - parasitology; Solanum chomatophilum; Solanum stoloniferum; Time Factors; wild plants; wild potatoes
• ISSN: 0022-0493; 1938-291X
• DOI: 10.1603/0022-0493%282008%29101%5B584%3AWSRTAA%5D2.0.CO%3B2

The type (antixenosis or antibiosis) of resistance against the aphids Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) was characterized for the wild tuber-bearing potatoes, Solanum chomatophilum Bitter and Solanum stoloniferum Schltdl. & Bouché through behavioral (olfactometry and electrical penetration graph) and physiological studies. In dual-choice assays, only S. stoloniferum exerted attraction to M. euphorbiae. This ruled out the possibility that plant volatiles of S. chomatophilum and S. stoloniferum may contribute to the high resistance expressed. In electrical penetration graph experiments, aphids feeding on S. stoloniferum showed increased salivation phases, whereas phloem ingestion was drastically reduced for both aphid species. Because reaching phloem elements was not delayed in both species, the resistance mechanism was phloem-located. The antixenosis exhibited by S. stoloniferum was similar on young and mature leaves. S. chomatophilum also showed phloem-located antixenosis against M. persicae. In contrast, M. euphorbiae had no difficulty to reach S. chomatophilum phloem tissues and to ingest sap. S. chomatophilum resistance against M. euphorbiae was antibiosis and only expressed in mature leaves, where a complete nymphal mortality was observed.