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Gojko Jelenkovic, Sharon Billings, Qi Chen, James Lashomb, George Hamilton, and Gerald Ghidiu

A population of 300 putative transgenic eggplants (Solanum melongena L.) carrying the syn cryIIIA gene was produced and tested for resistance to the Colorado potato beetle [CPB; Leptinotarsa decemlineata (Say)]. Toxicity tests in planta and in vitro demonstrated that 69% of the transformed plants were resistant to neonate larvae and adult CPB. Transgenicity of the plants was confirmed by studies of GUS expression and Southern and northern analysis. Primary transformants, having a single insert of the construct, upon selfing, produced progenies cosegregating for the uidA and syn cryIIIA genes at the expected 3:1 ratios with a few exceptions in which only one of the genes was expressed. The latter was attributed to the gene silencing phenomenon. The segregating resistant R1 seedlings showed the same level of resistance as the parental genotypes in growth chamber tests and under field conditions. One genotype carrying two copies of the construct, upon selfing, segregated at a 15:1 ratio for GUS expression and resistance to CPB, while Southern analysis revealed a 9:3:3:1 genotypic segregation ratio for individual copies of the construct.

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Conrad Cloutier

Tests in experimental plots over two seasons have shown that it is possible to obtain excellent control of eggs and larvae of the Colorado potato beetle (CPB) (Leptinotarsa decemlineata) under Quebec growing conditions by augmentative releases of a generalist predator, the twospotted stinkbug P. bioculatus. The stinkbugs were mass-reared on CPB eggs and larvae in the laboratory, and were released as second or third instar nymphs at the time of peak beetle oviposition. They were introduced manually at ratios of 2-4 predators : beetle egg mass in plots comprising ≈1000 `Kennebec' potato plants. Short-interval sampling after introduction indicated good rates of establishment and survival of the released P. bioculatus nymphs. Analysis of CPB egg recruitment and mortality indicated high rates of destruction of CPB eggs by the stinkbug. Egg destruction was followed by significant predation of late-instar bugs on CPB larvae, resulting in significant reductions of CPB prepupal and adult densities, and excellent foliage protection in treated plots compared to untreated controls. The results will be discussed with reference to traits of P. bioculatus that make it a good candidate for biocontrol of the CPB, and to problems yet to be resolved before augmentative releases of the predator can be used as an integrated pest management tactic in larger scale potato production.

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Qi Chen, Gojko Jelenkovic, Chee-Kok Chin, Sharon Billings, Jodi Eherhardt, Joseph C. Goffreda, and Peter Day

Three constructs of a coleopteran toxic cryIIIB Bacillus thuringiensis gene were engineered and incorporated into eggplant (Solanum melongena L.). Southern blot analysis of the eight primary transformants and segregational analysis of their R, progenies indicated that the chimeric cryIIIB constructs in each of the transgenic plants were stably incorporated at a single locus or at multiple sites within the same linkage group and that they were regularly transmissible to the progeny. The results of Northern blot and RNase protection analyses demonstrated that transcription of the cryIIIB mRNA takes place in plant cells, but only a small amount of the expected entire length transcripts were produced. The amount of the 5' end mRNA fragment produced was at least 30 to 40 times more abundant than the amount of the 3' end mRNA fragment. This could be interpreted to mean that either the two ends of the mRNA are of different stability or that the transcription process is often interrupted and only a few mRNAs complete the entire process to the end. When the transgenic plant mRNA was reverse-transcribed, amplified by polymerase chain reaction, and hybridized to the cryIIIB probe, two smaller molecular weight mRNA species were identified. Thus, the preponderance of the cryIIIB mRNA in transgenic plants exists as a truncated species, a situation similar to that of cryI genes when expressed in transgenic plants. Seedlings from the eight independent transgenic plants were tested for Coleopteran insect resistance. However, they did not demonstrate any significant resistance to the first and second instar larvae of the Colorado potato beetle (Leptinotarsa decemlineata Say).

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Francis Zvomuya and Carl J. Rosen

Current techniques used in genetic transformation can result in variation of numerous traits in addition to the transformed trait. Backcrossing to the standard genotype can eliminate this variation, but because of the heterozygous nature of potatoes (Solanum tuberosum L), backcrossing is not effective. Therefore, the chances of obtaining altered performance in transformed potato are high. `Superior' potato plants were recently genetically modified to resist attack and damage by the Colorado potato beetle [Leptinotarsa decemlineata (Say)]. The transformed clone, `NewLeaf Superior' (`NewLeaf'), has been shown in previous field trials to be more vigorous than the standard clone. The objective of this 2-year study was to evaluate the performance of `NewLeaf' relative to that of the standard clone at various fertilizer nitrogen (N) levels. The two clones were randomly assigned as subplots to main plots consisting of four N levels (28, 112, 224, or 336 kg·ha-1). Based on regression analysis, total yield was higher for `NewLeaf' than for `Superior' at N rates below 92 kg·ha-1 in 1997. At higher rates, however, `Superior' had higher yields than the transgenic clone. In 1998, the clon×N rate interaction was significant, but there was no consistent trend to the response of the two clones to N application. At the 112 kg·ha-1 N rate, total yield was higher for `NewLeaf' than for `Superior', but yields were similar for the two clones at other N rates investigated. Nitrogen and biomass accumulation in vines increased more for `NewLeaf' than for `Superior' as N rate was increased from 28 to 336 kg·ha-1. At equivalent N rates, these traits were higher for the transformed than for the standard clone within the range of N rates investigated. However, harvest index at equivalent N rates was higher for the standard clone than for `NewLeaf'. `Superior' and `NewLeaf' produced similar tuber dry weight yields per unit of N supplied and per unit of N absorbed by the plant. Nitrogen uptake efficiency (NUE) was 16% higher for `NewLeaf' than for the standard clone at the low N rate (112 kg·ha-1), whereas at higher N rates NUE was either lower for `NewLeaf' or similar for the two clones. This observation, together with the finding that yield for `NewLeaf' was maximized at lower N levels than the standard clone, suggests that `NewLeaf' may require lower N input than the standard clone. Results from the study indicate that the greater efficiency of `NewLeaf' at lower N levels was associated with acquisition of N from the soil rather than utilization of absorbed N in metabolism.

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Mark E. Clough, George C. Yencho, Barbara Christ, Walter DeJong, Donald Halseth, Kathleen Haynes, Melvin Henninger, Chad Hutchinson, Matt Kleinhenz, Greg A. Porter, and Richard E. Veilleux

.), Fusarium dry rot ( Fusarium spp.), golden nematode ( Heterodera rostochiensis ), and colorado potato beetle ( Leptinotarsa decemlineata ) resistance are long-term priorities. The NE1031 project is highly collaborative and takes advantage of the multiple

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Nina Devrnja, Jelena Milojević, Ljiljana Tubić, Snežana Zdravković-Korać, Aleksandar Cingel, and Dušica Ćalić

(Leptinotarsa decemlineata) J. Nat. Prod. 47 964 969 Skvarla, J.J. Turner, B.L. Patel, V.C. Tomb, A.S. 1977 Pollen morphology in the Compositae and in morphologically related families, p. 141–248. In: Heywood, V.H., J.B., Harborne, and B.L. Turner (eds.). The

Open access

Wenlei Guo, Li Feng, Dandan Wu, Chun Zhang, and Xingshan Tian

al., 2003 ). Our flaming machine could generate combustion temperatures as high as 1040 °C, which was hot enough to heat pests rapidly. It was reported that the legs of colorado potato beetles ( Leptinotarsa decemlineata ) could be irreparably damaged

Open access

Christian T. Christensen, Lincoln Zotarelli, Kathleen G. Haynes, and Charles Ethan Kelly

deterrents of colorado potato beetle [ Leptinotarsa decemlineata ( Bamberg et al., 1996 ; Mweetwa et al., 2011 ; Sinden et al., 1980 )]. S. chacoense naturally produces unreduced gametes ( Capo et al., 2002 ; Leue and Peloquin, 1980 ), which allows for

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Maria A. Estrada, Kelly Zarka, Susannah Cooper, Joseph Coombs, David S. Douches, and Edward J. Grafius

.J. Douches, D.S. Cooper, S.G. Grafius, E.J. Pett, W.L. Moyer, D.D. 2005 Combining natural and engineered host plant resistance mechanisms in potato (S olanum tuberosum L.) for Colorado potato beetle ( Leptinotarsa

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Rebecca J. Long, Rebecca N. Brown, and José A. Amador

beetles ( Leptinotarsa decemlineata Say) on potatoes in both 2013 and 2014. In addition, a spinosad spray, Entrust (Dow AgroSciences, Indianapolis, IN), was used for Colorado potato beetles in 2014. Although most practices adhered to the standards of