Main content area

Relationship between Colorado potato beetle (Coleoptera: Chrysomelidae) and tobacco hornworm (Lepidoptera: Sphingidae) resistance in Lycopersicon hirsutum f. glabratum

Sorenson, C.E., Fery, R.L., Kennedy, G.G.
Journal of economic entomology 1989 v.82 no.6 pp. 1743-1748
Solanum lycopersicum var. lycopersicum, pest resistance, Leptinotarsa decemlineata, Manduca sexta, mortality, host-parasite relationships
Segregation patterns of glandular trichome-mediated resistance to Leptinotarsa decemlineata (Say) and to Manduca sexta (L.) were examined in short-term foliage consumption bioassays for the following plant populations: Lycopersicon esculentum Mill. 'Walter', susceptible parent; L. hirsutum f. glabratum C.H. Mull, PI 134417, resistant parent; F2 (('Walter' X PI 134417) X ('Walter' X PI 134417)); 'Walter' X F1 ('Walter' X PI 134417); and F1 ('Walter' X PI 134417) X PI 134417. The component of L. decemlineata resistance associated with the foliar glandular trichomes segregated in a manner identical to M. sexta resitance. Because the levels of resistance to both insect species were highly correlated in segregating F1 backcross populations (r = 0.827; P less than or equal 0.001), a common mechanism is indicated. PI 134417 also possesses a L. decemlineata resistance component associated with the foliar lamellae which causes extensive mortality (98%) of late instars and pupae compared with beetles reared on foliage of the commercial tomato cultivar 'Walter' (average mortality, 57%). F1 plants from crosses between 'Walter' and PI 134417 were shown to lack the trichome-mediated component of resistance to L. decemlineata but to possess significant levels of the lamella-based resistance component (average mortality, 89%). Thus, the lamella-based and trichome-mediated resistance components are under separate genetic control.