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71.
The aim of this study was to investigate how three vascular plant species (Calluna vulgaris, Eriophorum angustifolium and Eriophorum vaginatum) colonising an abandoned cutover peatland affect fluxes of recent photosynthate to dissolved organic carbon (DOC), soil and plant respiration and shoot biomass. We used in situ 13CO2 pulse labelling to trace carbon (C) throughout a 65 day pulse chase period. Between 16 and 35% of the pulse of 13C remained in shoot biomass after 65 days with significant differences between C. vulgaris and E. angustifolium (P = 0.009) and between C. vulgaris and E. vaginatum (P = 0.04). A maximum of 29% was detected in DOC beneath labelled plants and losses of 13C from peat respiration never exceeded 0.16% of the original pulse, showing that little newly fixed C was allocated to this pool. There were no significant differences between the different plant species with respect to 13C recovered from DOC or via peat respiration. More C was lost via shoot respiration; although amounts varied between the three plant species, with 4.94–27.33% of the 13C pulse respired by the end of the experiment. Significant differences in 13C recovered from shoot respiration were found between C. vulgaris and E. angustifolium (P = 0.001) and between E. angustifolium and E. vaginatum (P = 0.032). Analysis of δ13C of microbial biomass indicated that recently assimilated C was allocated to this pool within 1 day of pulse labelling but there were no significant differences in the 13C enrichment of the microbial biomass associated with the different plant species. The data suggest that peat respiration represents a small flux of recent assimilate compared to other fluxes and pools and that different vascular plant species show considerable variation in the quantities and dynamics of C allocated to DOC. 相似文献
72.
Yonas Moges Gelaw John S. Y. Eleblu Kwadwo Ofori Berhanu Amsalu Fenta Clare Mukankusi Samuel Offei 《Plant Breeding》2023,142(3):357-371
Common bean is one of the widely consumed food security crop in Africa, Asia and South America. It is a rich source of protein, minerals and micronutrients. High genotype by environment interaction is one of the main challenge in breeding for high grain micronutrient concentration. The objective of this study was to estimate SNP markers associated with grain Fe and Zn concentration using 289 common bean genotypes and 11,480 SNP markers. The study revealed that 43 quantitative trait loci (QTLs) were associated with grain Fe and Zn concentration. Five quantitative trait nucleotides (QTNs), that is, QTN Fe_1.1, QTN Fe_6.3, QTN Fe_6.5, QTN Fe_10.3 and QTN Fe_11.6 were detected both at Haramaya and Melkassa locations. Two of the markers, that is, QTN Fe_6.3 and QTN Fe_6.5, were located on chromosome 06 while QTN Fe_1.1, QTN Fe_10.3 and QTN Fe_ 11.6 were residing on chromosomes 01, 10 and 11, respectively. Among these, QTN Fe_11.6 had a large and positive consistent effect across locations. The five stable QTNs along with the potential candidate genes could be used for Fe biofortification through marker assisted selection. 相似文献
73.
74.
Alison M. Miller Julianne M. O’Reilly-Wapstra Brad M. Potts Clare McArthur 《New Forests》2011,42(3):301-316
Mammalian herbivores regularly browse plantation seedlings. In many areas, seedlings require some form of protection if they
are to survive and grow into a productive plantation. Two general approaches for reducing browsing damage to seedlings are
to apply chemical repellents and tree guards. Both methods have existed for a long time, and new variations are constantly
being developed. Seedling stocking guards, a type of tree guard, are being used operationally in Tasmania, Australia, but
there is limited data quantifying their effectiveness and concerns with negative effects on tree performance. Conversely,
although proven effective, repellents are not being used, but are potentially cheaper and less problematic. We therefore aimed
to determine which is more effective under operational conditions, whether this effectiveness can be improved or extended,
and if either treatment has any effects on seedling form or survival. We planted Eucalyptus nitens seedlings with combinations of repellent and stocking guards in six operational plantations to examine and compare their
effectiveness. Seedlings were monitored for 12 months to examine treatment longevity. We found that both stocking guards and
repellent significantly reduced and delayed browsing severity, with their effects being additive. No negative effects on growth
were evident after 12 months, but adverse effects on seedling form warrant further investigation. Both of these methods can
be easily and relatively cheaply applied in the nursery before planting, making them appealing options to reduce browsing.
However, the ideal method for a given site will depend upon local browsing intensity. 相似文献
75.
W.M. Muir 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2007,124(6):342-355
Accuracy of prediction of estimated breeding values based on genome-wide markers (GEBV) and selection based on GEBV as compared with traditional Best Linear Unbiased Prediction (BLUP) was examined for a number of alternatives, including low heritability, number of generations of training, marker density, initial distributions, and effective population size (Ne). Results show that the more the generations of data in which both genotypes and phenotypes were collected, termed training generations (TG), the better the accuracy and persistency of accuracy based on GEBV. GEBV excelled for traits of low heritability regardless of initial equilibrium conditions, as opposed to traditional marker-assisted selection, which is not useful for traits of low heritability. Effective population size is critical for populations starting in Hardy-Weinberg equilibrium but not for populations started from mutation-drift equilibrium. In comparison with traditional BLUP, GEBV can exceed the accuracy of BLUP provided enough TG are included. Unfortunately selection rapidly reduces the accuracy of GEBV. In all cases examined, classic BLUP selection exceeds what was possible for GEBV selection. Even still, GEBV could have an advantage over traditional BLUP in cases such as sex-limited traits, traits that are expensive to measure, or can only be measured on relatives. A combined approach, utilizing a mixed model with a second random effect to account for quantitative trait loci in linkage equilibrium (the polygenic effect) was suggested as a way to capitalize on both methodologies. 相似文献
76.
G St Jean R T Skarda W W Muir G F Hoffsis 《American journal of veterinary research》1990,51(8):1232-1236
Xylazine (0.05 mg/kg of body weight diluted to a 5-ml volume, using 0.9% NaCl) or 5 ml of 0.9% NaCl was administered epidurally into the first caudal intervertebral space (Co1-Co2) in 8 cows (mean +/- SD body weight, 583 +/- 150 kg). Cows were observed for responses to deep needle pricking of the caudal dermatomes (S3 to Co), sedation, and ataxia. Heart rate, respiratory rate, body temperature, rate of ruminal contractions, coccygeal arterial blood pressure, pHa, blood gas tension (PaO2, PaCO2), base excess, total solids concentration, and PCV were determined before and after xylazine administration. Epidurally administered xylazine induced sedation and selective (S3 to Co) analgesia for at least 2 hours. Mild ataxia of hind limbs was observed in 6 cows, but all cows remained standing. Heart rate, respiratory rate, rate of ruminal contractions, arterial blood pressure, PaO2, PCV, and total solids concentration were significantly (P less than 0.05) decreased, and PaCO2, base excess, and bicarbonate concentration were significantly (P less than 0.05) increased after xylazine administration. Epidurally administered 0.9% NaCl did not alter sensory perception to needle pricking and did not affect any of the physiologic variables determined. Although epidural administration of xylazine induced analgesia and sedation in healthy cows, it should be avoided for epidural analgesia in cattle with heart disease, lung disease, and/or gastrointestinal disease because of its potent cardiopulmonary and ruminal depressant effects. 相似文献
77.
Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage 总被引:5,自引:0,他引:5
Da Costa Gómez TM Radtke CL Kalscheur VL Swain CA Scollay MC Edwards RB Santschi EM Markel MD Muir P 《Veterinary surgery : VS》2004,33(1):49-55
OBJECTIVES : To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. STUDY DESIGN : An ex vivo experimental model. SAMPLE POPULATION : A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. METHODS : Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.175 mJ/mm2, 4 Hz) ESWT treatments were randomized to the proximal and distal segments and the middle segment was used as a treatment control for pre-existing microcracks. After treatment, bone specimens were bulk-stained with basic fuchsin and microcracks were quantified in transverse calcified bone sections. RESULTS : ESWT had small but significant effects on microcracks. Microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) were increased after focused ESWT, whereas Cr.Le was increased after radial ESWT. In racing Thoroughbreds, Cr.Le increased with increased number of races undertaken. Cr.Dn and Cr.S.Dn were not significantly influenced by the number of races undertaken. CONCLUSION : ESWT has small but significant effects on bone microcracking ex vivo. CLINICAL RELEVANCE : These preliminary data suggest that ESWT has the potential to increase bone microcracking in equine distal limb bone in vivo. Such effects may be more pronounced in Thoroughbreds that are actively being raced, because in vivo microcracking increases with increased number of races undertaken. 相似文献
78.
Cruciate disease is a common cause of chronic lameness in dogs. Midsubstance rupture of the cranial cruciate ligament (CCL) arises from progressive pathological failure, often under conditions of normal loading in adult dogs with CCL instability. A high risk of rupture is associated with inflammation of the synovium and adaptive or degenerative changes in the cells and matrix of the CCL. In contrast, CCL rupture in puppies is usually associated with traumatic injury and avulsion of the CCL from its sites of attachment. 相似文献
79.
Immunohistochemical differentiation of reactive from malignant mesothelium as a diagnostic aid in canine pericardial disease 下载免费PDF全文
E. Milne Y. Martinez Pereira C. Muir T. Scase D. J. Shaw G. McGregor L. Oldroyd E. Scurrell M. Martin C. Devine H. Hodgkiss‐Geere 《The Journal of small animal practice》2018,59(5):261-271