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Feeding behaviour and performance of different populations of the black currant‐lettuce aphid, N asonovia ribisnigri , on resistant and susceptible lettuce
Author(s) -
ten Broeke Cindy J.M.,
Dicke Marcel,
Loon Joop J.A.
Publication year - 2013
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/eea.12084
Subject(s) - biology , virulence , aphid , population , locus (genetics) , botany , population dynamics , herbivore , horticulture , gene , genetics , fecundity , demography , sociology
When crops are bred for resistance to herbivores, these herbivores are under strong selection pressure to overcome this resistance, which may result in the emergence of virulent biotypes. This is a growing problem for crop species attacked by aphids. The Nr ‐gene in lettuce confers near‐complete resistance against the black currant‐lettuce aphid, N asonovia ribisnigri ( M osely) ( H emiptera: A phididae). Since 2007, populations of N . ribisnigri have been reported in several locations in E urope to infest resistant lettuce varieties that possess the Nr ‐gene. The objective of this study was to analyse the behaviour and level of virulence of several N . ribisnigri populations observed to have colonized Nr ‐locus‐containing lettuce lines. We analysed the stylet penetration and feeding behaviour, and the performance of these N . ribisnigri populations on resistant and susceptible lettuce lines. Large variation in the degree of virulence to the Nr ‐locus‐containing lettuce lines was found among populations of the Nr:1 biotype. The G erman population was highly virulent on the Nr ‐containing resistant lettuce lines, and showed similar feeding behaviour and performance on both the susceptible and resistant lettuces. The F rench population from P aris was the second most virulent, though reproduction on the resistant lines was reduced. The F rench population from P erpignan and a population from B elgium, however, showed reduced performance and feeding rate on the resistant compared to the susceptible lettuces. The lettuce background in which the Nr ‐gene is expressed influences the level of resistance to the various Nr:1 aphid populations, because the performance and feeding behaviour differed between the aphids on the cultivars (romaine lettuce) compared to the near‐isogenic lines (butterhead/iceberg lettuce). This study also shows that being able to feed on a plant not automatically implies that a population can successfully develop on that plant, because aphids showed phloem ingestion during the 8‐h recording period on resistant lettuce, but were not able to survive and reproduce on the same lettuce line.