Physical traits in raspberry provide resistance to pests and diseases

Plants with physical resistance traits can be remarkably effective against insect herbivores. In this study we looked at a root trait (root mass) and a leaf trait (adaxial hairiness) in Rubus idaeus and demonstrated significant differences between varieties. The responses of two insect pests, the vine weevil, Otiorhynchus sulcatus, and the large raspberry aphid, Amphorophora idaei, differed to raspberry varieties. Larval mass of O. sulcatus exhibited a complex relationship with root mass while mass of A. idaei insects was largest on varieties with hairier adaxial leaf surfaces. We discuss the importance of understanding the mechanisms underlying physical resistance traits and the potential for exploiting robust genotypic differences in pest and disease resistance in soft fruit breeding programmes.