HortScience (2001) 36, 967-970

D.S. Douches, T.J. Kisha, J.J. Coombs, W. Li, W.L. Pett and E.J. Grafius (2001)
Effectiveness of natural and engineered host plant resistance in potato to the Colorado potato beetle
HortScience 36 (5), 967-970
Abstract: The Colorado potato beetle, Leptinotarsa decemlineata (Say), is the most serious insect pest of potatoes throughout the eastern and north central United States. Host plant resistance to the Colorado potato beetle has been identified in wild Solanum species and Bt-transgenic potato lines. Detached-leaf bioassays (72 h) were conducted on insecticide-resistant, first instar Colorado potato beetles to study the effectiveness of individual and combined host plant resistance traits in potato. Potato lines tested include non-transgenic cultivars ('Russet Burbank', 'Lemhi Russet', and 'Spunta'), a line with glandular trichomes (NYL235-4), a line with high foliar leptines (USDA8380-1), and transgenic lines expressing either codon-modified Bt-cry3A or Bt-cry5 (Bt-cry1Ia1). Bt-cry3A transgenic lines, foliar leptine line, and foliar leptine lines with Bt-cry5 had reduced feeding compared to non-transgenic cultivars. Glandular trichome lines and glandular trichome lines with Bt-cry5 did not reduce feeding in this no-choice feeding study. Some Bt-cry5 transgenic lines, using either the constitutive promoters CaMV35s or (ocs)₃mas (Gelvin super promoter), were moderately effective in reducing larval feeding. Feeding on Bt-cry5 transgenic lines with the tuber-specific patatin promoter was not significantly different than or greater than feeding on the susceptible cultivars. Mortality of first instars was highest when fed on the Bt-cry3A lines (68% to 70%) and intermediate (38%) on the Bt-cry5 'Spunta' line SPG3 where the gus reporter gene was not included in the gene construct. Host plant resistance from foliar leptines is a candidate mechanism to pyramid with either Bt-cry3A or Bt-cry5 expression in potato foliage against Colorado potato beetle. Without multiple sources of host plant resistance, long-term sustainability is questionable for a highly adaptable insect like the Colorado potato beetle.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): David S. Douches

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Leptinotarsa decemlineata	Potato (Solanum tuberosum)
Bacillus thuringiensis genes in crops (entomopathogen)	Leptinotarsa decemlineata	Potato (Solanum tuberosum)
Bacillus thuringiensis Cry3A-toxin (entomopathogen)	Leptinotarsa decemlineata	Potato (Solanum tuberosum)