The woolly apple aphid can be found from various locations around the world, and we know it occurs more densely within apple growing regions. In the past, rootstocks containing resistance (Er) genes have reliably provided below ground control, but populations around the world are adapting and overcoming resistance. At least one new genotype has emerged that has broken through rootstock resistance. To better understand how adaptation occurred, the distribution of this and related genotypes, and how we can protect apples against adaptation in the future we have developed a project with the following goals:
- We will identify how this insect overcomes rootstock resistance by characterizing its gene structure and function.
- We will identify if this genotype occurs broadly across growing regions (or if others with a similar capacity to adapt also occur) by characterizing genetic diversity of aphids from orchards, nurseries, and native host plants.
- We will identify plant genes/traits that enable or prevent success of the new genotype through functional assays, ultimately to advance rootstock development.
Stay tuned for updates!