In recent years the biology of resistance to aphids and othersap-sucking insects has been studied in detail, whereas thegenetic basis underlying this resistance is still poorly understood.Genetic resistance to Acyrthosiphon kondoi Shinji (bluegreenaphid; BGA) has been identified in Medicago truncatula Gaertnand backcrossed into susceptible cultivars. One of these M.truncatula cultivars named Jester also has good resistance to anAustralian biotype of pea aphid (PA; A. pisum Harris). Until nowit has been unclear whether resistance to each aphid species ofthe genus Acyrthosiphon is conferred by distinct genes or thesame gene termed AKR for A. kondoi resistance. Infestation ofthe progenitors of the cultivar Jester with both aphid speciesrevealed that resistance to BGA came from a different donor thanresistance to PA, demonstrating that resistance to these aphidspecies is mediated by different resistance genes. However, aninteraction between these genes for resistance to Acyrthosiphonspecies remains a possibility, given that PA resistance was notone of the parameters selected for in the creation of Jester. Theidentification of resistance to the model aphid, PA, and a closelyrelated aphid BGA in the same genetic background of the modellegume M. truncatula makes this system an attractive model forthe study of plant-aphid interactions, as well as R gene specificityand evolution.
|Journal||Plant Signaling and Behavior|
|Publication status||Published - 2009|