Segregation of leptine glycoalkaloids and resistance to Colorado potato beetle (Leptinotarsa decemlineata (Say)) in F2Solanum tuberosum (4x) ×S. chacoense (4x) potato progenies     

G. Craig Yencho  Stanley P. Kowalski  George G. Kennedy  Lind L. Sanford 《American Journal of Potato Research》2000,77(3):167-178

Solanum chacoense Bitter is resistant to the Colorado potato beetle (CPB),Leptinotarsa decemlineata (Say). Resistance has been associated with the presence of a rare class of glycoalkaloids, the leptines. In this study, seven tetraploid, F2S. tuberosum xS. chacoense families were evaluated for foliar production of leptines I and II, leptinines I and II, and α-solanine and α-chaconine; and screened for resistance to CPB in the laboratory and field. Resistance was correlated with the concentrations of glycoalkaloids on a family and an individual basis. Leptine concentrations ranged from undetectable to a high of 18.0 mg/g dry weight. All of the progeny produced solanine and chaconine. Family 9623 had the highest mean leptine concentration and the lowest mean leaf disk feeding and CPB defoliation levels. Family 9616 had the lowest mean glycoalkaloid concentration and ranked as one of the most susceptible families. Regression analyses of solanine + chaconine, leptine I and II, and leptinine I and II foliar concentrations versus leaf disk consumption and field defoliation revealed that only increased foliar levels of leptines resulted in decreased CPB feeding. The regression models for leptines versus leaf disk consumption and field defoliation were highly significant, accounting for 17% and 26% of the variation in consumption and defoliation, respectively. To the best of our knowledge, this is the first work reporting the impact of leptine and leptinine concentrations on CPB feeding in tetraploid,S. tuberosum xS. chacoense potato hybrids. Results are discussed within the context of breeding for resistance to CPB.  相似文献   

Public preferences regarding rabies-prevention policies in the UK     

Mark Cox  Edward B Barbier  Piran C. L. White  Geraldine A. Newton-Cross  Lorraine Kinsella  Heather J. Kennedy 《Preventive veterinary medicine》1999,41(4):221-270

The current 6-month quarantine system for all cats and dogs entering the UK has kept the UK rabies-free since 1922. However, pressure is mounting for a change to a system of vaccination, microchip identification and serological testing. In response to the increasing controversy surrounding the quarantine system, the UK government recently set up an independent review panel to assess the alternatives. This paper quantifies public preferences for the current policy and three alternative rabies-prevention measures. A survey was used not only to assess the overall preferences for rabies-prevention policies but also to assess the importance of policy attributes and socio-economic characteristics in determining policy preferences. We interviewed a sample of pet-owners in North Yorkshire. The results showed that the existing system was the single most-preferred policy option. However, a large proportion of the sample preferred the vaccination-based policies. A logistic-regression model and ordered probit models were used to find that safety and animal welfare were the most-important factors determining policy preferences. The respondents' awareness of the rabies-policy review, a desire to take a pet abroad, the amount of foreign travel, occupation and previous experience of quarantine were all important factors in policy choice. Socio-economic characteristics such as income, pets owned and the number of children were not significant determinants of policy preference.  相似文献   

"The clinical scope of porcine reproductive and respiratory syndrome virus infection has expanded since 1987": an alternative perspective.     

J A Ellis  S Krakowa  G Allan  E Clark  S Kennedy 《Veterinary pathology》1999,36(3):262-265

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The incorporation of environmentally derived 87Sr/86Sr and Sr/Ca in early otolith formation of Chinook salmon     

Paul Chittaro  Jens Hegg  Abby Fuhrman  Devin Robichaux  Rothboury Doung  Brian Beckman  Chris Fisher  Jeff Vervoort  Brian Kennedy 《Ecology of Freshwater Fish》2023,32(1):107-119

Effective species management often requires understanding patterns of movement and habitat use. A common approach in identifying where individuals reside relies upon chemical tracers from the environment that are incorporated into an individual's tissues. For fish, isotopes in their otoliths, specifically the portion of their otolith formed during their larval stage, have been used to identify the natal origin. Complicating this work, however, is the fact that during this life stage, there is a shift in the source of isotopes deposited onto the growing otolith from maternally to environmentally derived. The objective of this study was to identify the portion of the otolith representing this transition to environmentally derived isotopes so as to accurately investigate questions of natal origin for a threatened population of fall Chinook salmon (Oncorhynchus tshawytscha). We exposed developing larvae to four treatments that differed in terms of their water strontium isotope ratio (⁸⁷Sr/⁸⁶Sr) and used change-point analysis of otolith ⁸⁷Sr/⁸⁶Sr and strontium to calcium ratio (Sr/Ca) to identify the otolith radius corresponding to the transition to environmentally derived isotopes. Our results indicated this transition occurred, on average, at 132 μm (⁸⁷Sr/⁸⁶Sr; ±50 μm standard deviation) and 127 μm (Sr/Ca; ±29 μm) from the otolith core, which corresponded to the developmental time between hatching and exogenous feeding. A substantial proportion of our otoliths (i.e., 61%) did not show convergence between otolith and water ⁸⁷Sr/⁸⁶Sr by the end of the 113-day experiment, which was likely due to the dietary contribution of marine-based feed. Therefore, we were unable to recommend an otolith radius to target for the purposes of reconstructing natal origin apart from being beyond approximately 130 μm.  相似文献