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81.
82.
John A. Henning M. Shaun Townsend David H. Gent Nahla Bassil Paul Matthews Emily Buck Ron Beatson 《Euphytica》2011,180(3):411-420
Hop powdery mildew [Podosphaera macularis (Wallr.) U. Braun & S. Takam.] is best controlled via the production of resistant varieties. Recent evidence supports selection
against plant susceptibility genes to fungal pathogens as a more durable resistance mechanism than selection for resistance
genes. The objective of this study was to identify molecular-based QTLs, their genetic effects and epistasis among QTLs associated
with susceptibility to powdery mildew. Parents and offspring from the cross, ‘Perle’ × ‘USDA 19058M’, were clonally replicated
and inoculated in a greenhouse using a CRD experimental design in Corvallis, OR. DNA was extracted, purified and analyzed
via three different marker systems. Analysis of the resulting markers was based upon the “two-way pseudo-testcross” procedure.
QTL mapping using multiple interval mapping and Bayesian interval mapping analyses were performed using WinQTL Cartographer
2.5_003. Comparison amongst mapping analyses identified three persistent QTLs on three linkage groups without significant
epistatic effect upon expression. The persistent QTL on linkage group C7 had both additive and dominant effects controlling
phenotype expression. The presence or absence of the two AFLP markers bordering the QTL on C7 defined susceptibility in offspring.
This is the first report in hop identifying molecular markers linked to QTLs associated with disease susceptibility. 相似文献
83.
Sauer J. Dewert A. Hondelmann P. Meyhöfer R. Hommes M. Buck H. Ulrichs C. Vogler U. 《植物病害和植物保护杂志》2021,128(3):865-870
Journal of Plant Diseases and Protection - The carrot psyllid Trioza apicalis Förster 1848 is a carrot pest in Europe that can cause serious damages in case of massive occurrence. Damages up... 相似文献
84.
Agroforestry policy issues and research directions in the US and less developed countries: insights and challenges from recent experience 总被引:8,自引:0,他引:8
L. E. Buck 《Agroforestry Systems》1995,30(1-2):57-73
Efforts to improve the performance of agroforestry systems, and to expand the land area and number of people able to benefit from this integrative approach to agriculture and natural resource management, are constrained throughout the world by non-supportive land use policies. A growing sense of urgency that policy change is needed to enable agroforestry to flourish has contributed during the past two years to an unprecedented level of agroforestry policy assessment and planning activity.In the US, agroforestry has emerged from academia, where it has incubated since the mid-1980s, into the professional resource management arena. A multi-organizational agroforestry evaluation process has driven national policy and program formation to the forefront of the agenda of the agroforestry community, as it seeks to influence the 1995 Farm Bill. Internationally, the Consultative Group on International Agricultural Research and collaborators fostered a sequence of policy issue identification activities as a basis for setting strategic research priorities for forestry and agroforestry.Following a brief review of forces driving agroforestry development in industrialized and less developed countries, the paper highlights recent policy assessment initiatives in each sphere. Observations on the issues driving and the priorities emerging from these processes are offered, to lend perspective to the critical challenges facing the agroforestry policy research community. An explanation for pervasive constraints and inconsistencies in policy effectiveness is then explored, from which a promising approach to research intervention is forwarded.It is argued that social scientists might influence agroforestry policy most favorably at this critical juncture, as perceptions of inter-dependence increase among different stakeholders in the policy system, by employing interventionist, actor-oriented perspectives and participatory methods to facilitate policy innovation and evaluation. The approach is consistent with participatory technology design processes that earlier helped to establish agroforestry as a prototype for sustainable development. 相似文献
85.
86.
Brassica napus is one of the crops at the forefront of biotechnological development. The procedures used to produce transgenic varieties
are all prone to generating plants with multiple transgene copies. There has been considereable interest in the behaviour
of such multi-copy lines because gene dosage rarely appears to correlate simply with gene expression. Here we report the analysis
of a population of 107 progeny from a B. napus transformant containing multiple copies of a GUS marker gene construct. A total of 12 GUS sequence copies were identified
including one that was non-functional. The expression of GUS increased with increasing copy number but this increase only
made up a small proportion of the total variation between lines. There was no evidence of interaction between the various
GUS copies and they appeared to segregate independently. The variation between progeny lines indicated that the number of
gene copies was not a good guide to the expression of the gene product and hence that the expression of the gene in progeny
from a multiple-copy parent could not be predicted. The importance of these findings in relation to plant breeding and the
risk assessment process is discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
87.
I. Theuns P. Windels S. De Buck A. Depicker E. Van Bockstaele M. De Loose 《Euphytica》2002,123(1):75-84
A T-DNA fingerprinting method is presented based on amplified fragmentlength polymorphism with an anchored polymerase chain reaction step. Thismethod allows discrimination between different T-DNA inserts in stablytransformed plants. The technique was evaluated by analyzing 51 transgenicArabidopsis lines that had been characterized in detail by genomicblotting. Comparison of the obtained fingerprints with the availableintegration information demonstrated that fingerprints were correlated tothe predicted patterns, except for the inverted repeat junctions and forthose inserts with large deletions at the left or right border. Ourexperiments show that by using T-DNA fingerprinting multi-copy transgeniclines can be eliminated efficiently so that the technique can be used toenrich a population of transgenic plants for putative single-copytransformants. 相似文献
88.
Roxanne K. Buck Leith R.C. Meyer George F. Stegmann Sabine B.R. Kästner Maya Kummrow Christina Gerlach Geoffrey T. Fosgate Gareth E. Zeiler 《Veterinary anaesthesia and analgesia》2017,44(1):138-143
Objective
To characterize a propofol–medetomidine-ketamine total intravenous anaesthetic in impala (Aepyceros melampus).Study design
Prospective clinical study.Animals
Ten adult female impala.Materials and methods
Impala were immobilized at 1253 m above sea level with 2.0 mg thiafentanil and 2.2 mg medetomidine via projectile darts. Propofol was given to effect (0.5 mg kg?1 boluses) to allow endotracheal intubation, following which oxygen was supplemented at 2 L minute?1. Anaesthesia was maintained with a constant-rate infusion of medetomidine and ketamine at 5 μg kg?1 hour?1 and 1.5 mg kg?1 hour?1, respectively, and propofol to effect (initially 0.2 mg kg?1 minute?1) for 120 minutes. The propofol infusion was titrated according to reaction to nociceptive stimuli every 15 minutes. Cardiopulmonary parameters were monitored continuously and arterial blood gas samples were analysed intermittently. After 120 minutes' maintenance, the thiafentanil and medetomidine were antagonized using naltrexone (10:1 thiafentanil) and atipamezole (5:1 medetomidine), respectively.Results
All impala were successfully immobilized. The median dose [interquartile range (IQR)] of propofol required for intubation was 2.7 (1.9–3.3) mg kg?1. The propofol–medetomidine–ketamine combination abolished voluntary movement and ensured anaesthesia for the 120 minute period. Propofol titration showed a generally downward trend. Median (IQR) heart rate [57 (53–61) beats minute?1], respiratory rate [10 (9–12) breaths minute?1] and mean arterial blood pressure [101 (98–106) mmHg] were well maintained. Arterial blood gas analysis indicated hypoxaemia, hyper- capnia and acidaemia. Butorphanol (0.12 mg kg?1) was an essential rescue drug to counteract thiafentanil-induced respiratory depression. All impala regurgitated frequently during the maintenance period. Recovery was calm and rapid in all animals. Median (IQR) time to standing from antagonist administration was 4.4 (3.2–5.6) minutes.Conclusions and clinical relevance
A propofol–medetomidine–ketamine combination could provide adequate anaesthesia for invasive procedures in impala. The propofol infusion should begin at 0.2 mg kg?1 minute?1 and be titrated to clinical effect. Oxygen supplementation and airway protection with a cuffed endotracheal tube are essential. 相似文献89.
Diagnosis of bromethalin toxicosis in the dog 总被引:2,自引:0,他引:2
D C Dorman J Simon K A Harlin W B Buck 《Journal of veterinary diagnostic investigation》1990,2(2):123-128
Dogs given a single oral dose of bromethalin at 6.25 mg/kg developed a toxic syndrome characterized by hyperexcitability, tremors, seizures, depression, and death within 15-63 hours after bromethalin administration. Gross lesions included mild cerebral edema (2/5) and mild pulmonary congestion (2/5). Histologic lesions included diffuse white matter spongiosis (5/5), mild microgliosis (3/5), optic nerve vacuolization (3/5), mild thickening of Bowman's capsule (2/5), and occasional splenic megakaryocytes (2/5). Ultramicroscopic examination of midbrain stem revealed occasional swollen axons, intramyelinic vacuolization, and myelin splitting at the intraperiod line. Bromethalin was detected in kidney, liver, fat, and brain tissues, using gas chromatography with electron capture detection. Photodegradation of extracted bromethalin may limit accurate quantification of tissue residues. 相似文献
90.
R W Coppock R D Reynolds W B Buck B J Jacobsen S C Ross M S Mostrom 《Journal of the American Veterinary Medical Association》1989,195(10):1380-1381
Aflatoxicosis was diagnosed in 600 feeder pigs, of which 400 died, 150 were destroyed, and 50 were marketed. The pigs were exposed to 2,500 to 3,500 micrograms of aflatoxins/kg of feed. Drought-stressed damaged corn infected with Aspergillus flavus was stored under ambient conditions in a glass-lined silo, and this storage environment provided conditions that favored rapid fungal growth and mycotoxin production. 相似文献