Identification and evaluation of flea beetle (Phyllotreta cruciferae) resistance within Brassicaceae

All currently registered varieties of canola/oilseed rape, Brassica napus a nd B. rapa, are susceptible to attack by flea beetles, although to varying degrees. The development of resistant cultivars would be an environmentally acceptable means to reduce the damage caused by flea beetles. Seedlings fr om 10 species of Brassicaceae were evaluated for levels of antixenosis resi stance to flea beetles in the laboratory, along with 308 Sinapis alba/B. na pus hybrids. Thlaspi arvense and 11 cultivars of S. alba were resistant to feeding by flea beetles. In addition, 34 S. alba/B, napus hybrids were resi stant to feeding by flea beetle in at least one test, although many of thes e failed to demonstrate resistance with repeated testing. One hybrid line w as resistant to feeding by flea beetles each of the four times it was teste d, while another was resistant in three out of four tests. These data indic ate that resistance to flea beetles within the Brassicaceae is a genetic tr ait and can be transferred by interspecific hybridization. This information is the first step towards introgression of genetic sources of flea beetle resistance from resistant relatives into canola varieties.