Genetics of wood quality attributes in Western Larch     

Blaise Ratcliffe  Foster J. Hart  Jaroslav Klápště  Barry Jaquish  Shawn D. Mansfield  Yousry A. El-Kassaby 《Annals of Forest Science》2014,71(3):415-424

Context

Wood quality traits are important to balance the negative decline of wood quality associated with selection for growth attributes in gymnosperm breeding programs. Obtaining wood quality estimates quickly is crucial for successful incorporation in breeding programs.

Aims

The aims of this paper are to: (1) Estimate genetic and phenotypic correlations between growth and wood quality attributes, (2) Estimate heritability of the studied traits, and (3) Assess the accuracy of in situ non-destructive tools as a representative of actual wood density.

Methods

Wood density (X-ray densitometry), tree height, diameter, volume, resistance drilling, acoustic velocity, and dynamic modulus of elasticity were estimated, along with their genetic parameters, for 1,200, 20-year-old trees from 25 open-pollinated families.

Results

Individual tree level heritabilities for non-destructive evaluation attributes were moderate ( $ {\widehat{h}}_i^2=0.37-0.42 $ ), wood density and growth traits were lower ( $ {\widehat{h}}_i^2=0.23-0.35 $ ). Favorable genetic and phenotypic correlations between growth traits, wood density, and non-destructive evaluation traits were observed. A perfect genetic correlation was found between resistance drilling and wood density (r _G ?=?1.00?±?0.07), while acoustic velocity and dynamic modulus of elasticity showed weaker genetic correlations with wood density (r _G ?=?0.25?±?0.24;?0.46?±?0.21, respectively).

Conclusion

This study confirmed that resistance drilling is a reliable predictor of wood density in western larch, while the weak genetic correlations displayed by acoustic velocity and dynamic modulus of elasticity suggest limited dependability for their use as fast in situ wood density assessment methods in this species.  相似文献   

A classification and evaluation of Irish water beetle assemblages     

Garth N. Foster  Brian H. Nelson  David T. Bilton  Derek A. Lott  Robert Merritt  Richard S. Weyl  Michael D. Eyre 《水产资源保护:海洋与淡水生态系统》1992,2(2):185-208

1. Modern records of 165 species of wetland beetle (Haliplidae, Hygrobiidae, Noteridae, Dytiscidae, Gyrinidae, Georissidae, Hydrochidae, Helophoridae, Hydrophilidae, Hydraenidae, Scirtidae, Dryopidae, Elmidae, Chrysomelidae, Curculionidae) were assembled for analysis. 2. Two hundred and eighty nine modern lists of seven or more species of water beetle from sites in Ireland were subjected to multivariate analysis. 3. Ten assemblage types were identified using TWINSPAN. Habitats typical of these assemblages are: A. deep rivers; B. rivers with riffles; C. puddles; D. canals and lakes with rich vegetation; E. ponds and ditches; F. turloughs; G. natural, minerotrophic fens; H. base-flushed cutover bogs; I. peat bogs; J. montane flushes. The distribution of these types is discussed. 4. Ordination of site data by DECORANA indicated that the important environmental variables dictating water beetle assemblage type in Ireland were: flow; water permanence; exposure; type of substratum. Acidity could not be isolated as a determinant, except within the analysis of assemblage types conducted using TWINSPAN. DECORANA isolated one brackish site as an outlier but salinity was not otherwise a major factor, probably because few brackish sites were included in the analysis. 5. The number of modern records for each species was used to provide a provisional set of species-quality scores. A simple rationale was devised to weight these scores in favour of relict species and against elusive species, species with short-lived adults and species primarily associated with man-made habitats. 6. The average species-quality score per site and the number of species recorded were used to rank sites within each TWINSPAN end-group. The most diverse sites with the highest quality were some turloughs, rich fens and base-flushed peat cutting complexes. Some montane lakes and flushes with relatively few species had high species-quality scores.  相似文献   

Are cell redox or lactate dehydrogenase kinetics responsible for the absence of gluconeogenesis from lactate in sea raven,hepatocytes?     

Glen D. Foster  J. Zhang  T. W. Moon 《Fish physiology and biochemistry》1994,13(1):59-67

Previous studies have reported very low rates of gluconeogenesis from lactate in sea raven (Hemitripterus americanus) hepatocytes compared to other teleosts studied. This study examines whether hepatic cell redox or lactate dehydrogenase (LDH) characteristics may explain this observation. Sea raven hepatic optimal LDH activities (pyruvate reductase direction) were more than 40 times less compared with rainbow trout liver values (40 vs 1914 μmol·min⁻¹·g⁻¹ protein). The Km(lactate) was 9.24 and 0.86 mM for sea raven and trout hepatic LDH, but the Km(pyruvate) was similar between the two species (0.11 and 0.21 mM, respectively). These results suggested that sea raven liver LDH did not favour lactate use and was more indicative of the mammalian M-isozyme. Gel electrophoresis showed a predominant intermediate isozyme, with a small amount of the M-type LDH. Phosphoenolpyruvate carboxykinase (PEPCK) was localized to the mitochondrial compartment, while there was no apparent mitochondrial glutamate-oxaloacetate transaminase (GOT) activity. No in vitro lactate flux to glucose was found in untreated, 10 mM ethanol-treated, or 3 mM NH₄Cl-treated sea raven hepatocytes, although CO₂ production from lactate was decreased by ethanol and increased by NH₄Cl. These results provide evidence that cell redox does not limit gluconeogenesis from lactate, while low activities and the kinetic characteristics of LDH may partially explain the low lactate gluconeogenesis reported in sea raven hepatocytes. To whom correspondence should be addressed at University of Ottawa.  相似文献   

Heat stress: A major contributor to poor animal welfare associated with long-haul live export voyages     

Malcolm P. Caulfield  Heather Cambridge  Susan F. Foster  Paul D. McGreevy 《Veterinary journal (London, England : 1997)》2014,199(2):223-228

Recent investigations by the Australian Department of Agriculture, Fisheries and Forestry into high mortalities on live export voyages from Australia to the Middle East during the Northern hemisphere summer suggest that animal welfare may be compromised by heat stress. The live export industry has generated a computer model that aims to assess the risk of heat stress and to contain mortality levels on live export ships below certain arbitrary limits. Although the model must be complied with under Australian law, it is not currently available for independent scientific scrutiny, and there is concern that model and the mandated space allowances are inadequate. This review appraises the relevant literature on heat stress in sheep and cattle, including laboratory studies aimed at mimicking the ambient temperatures and humidity levels likely to be encountered on live export voyages. Animal welfare is likely to be very poor as a result of heat stress in some shipments.  相似文献   

Effects of Added Shelter and Stocking Density on Growth of Sleepy Cod Oxyeleotris lineolatus in Ponds   总被引：2，自引：0，他引：2  

Brett W.  Herbert Peter A.  Graham Scot D.  Foster 《Journal of the World Aquaculture Society》2003,34(4):433-440

Sleepy cod Oxyeleotris lineolatus is a species of freshwater goby in demand in Australian markets by consumers of Asian origin. It is related to marble goby Oxyeleotris marmoratus , the most expensive freshwater food fish in Asia, which is cultured throughout southeast Asia in ponds and cages. The performance of sleepy cod in culture conditions was investigated to assess the viability of farming them in northern Australia. Sleepy cod fingerlings (62.8 ± 0.8 mm total length and 2.56 ± 0.095 g) were stocked into experimental ponds at 32,857 fish/ha, and grown out for 8 mo. Shelter was provided in each of three replicate ponds and was absent in three control ponds. The provision of shelter in juvenile growout was found to be of no benefit, although fish in ponds provided with shelter weighed slightly more per unit length than fish in ponds without shelter. Cannibalism was not a problem in growout, and survival was close to 100%. After the shelter trial was completed, fish were graded into large and small classes (three replicates of each), and grown out without shelter at the same density for 158 d. Following that, fish were again graded, and the largest 30% retained from growout at a density of 8,857 fish/ha (large, 198 ± 6.44 g) or 10,000 fish/ha (small, 48.9 ± 1.27 g). These were grown out for 188 d. Growth of selected stock at low densities was slower than earlier growth rates, although smaller fish gained weight more rapidly than larger fish. Growth rates were better than the only published data for marble goby. Further investigation into high density culture and different genotypes of sleepy cod needs to be undertaken to determine the viability of pond culture.  相似文献   

大豆粕在非鲑鳟类海水鱼饲料中的使用     

Lan Foster 《中国水产》2003,(9)

~~大豆粕在非鲑鳟类海水鱼饲料中的使用@Lan Foster$夏威夷海洋研究所  相似文献   

Allergen-specific IgG antibodies in cats with allergic skin disease     

A.P Foster  H.A O'Dair  D.J DeBoer 《Research in veterinary science》1997,63(3):239

An enzyme-linked immunosorbent assay was developed for quantifying feline serum allergen-specific IgG directed against selected house dust, pollen and flea allergens. The assay was used to compare allergen-specific IgG concentrations in sera from healthy cats, cats with non-dermatologic illness, confirmed allergic cats and undiagnosed pruritic cats. Our results demonstrate that cats with confirmed allergic skin disease have significantly more IgG directed against house dust, flea and ryegrass allergens than other cat groups examined. These results support the theory that cats with allergic skin disease have an underlying T_H2 lymphocyte response that directs production of both allergen-specific IgG and IgE.  相似文献   

Shiga toxin-producing Escherichia coli as a perennial cause of abortion in a closed flock of Suffolk ewes     

Sargison ND  Howie F  Mearns R  Penny CD  Foster G 《The Veterinary record》2007,160(25):875-876

  相似文献   

Variation in the expression of self-fertility inLolium perenne L.     

C. A. Foster  C. E. Wright 《Euphytica》1970,19(1):61-70

Summary A series of experiments was conducted to determine the variations arising between replicate selfing units, to compare self-fertility and cross-fertility in the same environment and to measure the variation in expression of self-fertility by different techniques and in different environments.Variation in self-fertility between selfing units within genotypes was relatively high, representing approximately one-third of the total observed variation in a series of duplicate selfings of over 60 genotypes tested in one environment. In order to differentiate clearly between the self-fertility of a limited number of genotypes as many as four replicates were needed, although this number varied with the environment in which the tests were conducted. Levels of self-fertility were similar in bag selfing units placed inside or outside a glasshouse in an average year, but were greater outside than inside in a year which was drier and warmer than average. In a highly humid environment the mean level of self-fertility attained was reduced by a factor of three. Removal of flag leaf laminae had an adverse effect on self-fertility, reducing it by half. Shaking the pollination bags, as is the usual practice to promote pollen dispersal, increased self-fertility very considerably over that of unshaken controls. Assisting pollen dispersal by blowing filtered air into the bags was time-consuming and did not prove to be superior to the shaking technique. It is clear that self-fertility can neither be considered in isolation from the environment in which it is determined, nor can it justifiably be related to cross-fertility unless both are determined in the same environment. A sample of over 60 genotypes tested in one environment was on average 2.2% as self-fertile as they were cross-fertile, with a range for individual genotypes from 0–31%. Optimum conditions for maximum expression of self-fertility, essential in the exploitation of this character in ryegrass breeding, have yet to be fully established.  相似文献   

Dynamic Modelling of Spatially Variable Catchment Hydrochemistry for Critical Loads Assessment     

Helen J. Foster  Matthew J. Lees  Howard S. Wheater  Colin Neal  Brian Reynolds 《Water, air, and soil pollution》2001,130(1-4):1283-1288

Concern about acidification in upland areas has brought about the need to model the stream hydrochemical response to deposition and land-use changes and calculate critical loads. Application of dynamic models such as MAGIC are preferable to steady-state methods, since they are able to produce an estimate of the time scale required to meet some water chemistry target given a reduction in acid deposition. These models typically consider annual changes in stream chemistry at one point. However, in order to protect biota from 'acid episodes', quantification of temporal variability needs to encompass event responses; in addition spatial variability across the catchment also needs to be considered. In this paper, modelling of both spatial and temporal variability is combined in a new framework which enables quantification of catchment hydrochemical variability in time and space. Both low and high flow hydro-chemical variability are quantified in terms of statistical distributions of ANC (Acid Neutralisation Capacity). These are then input as stochastic variables to an EMMA (End-Member Mixing Analysis) model which accounts for temporal variability and ANC is hence predicted as a function of time and space across the whole catchment using Monte-Carlo simulation. The method is linked to MAGIC to predict future scenarios and may be used by iteration to calculate critical loads. The model is applied to the headwaters of the River Severn at Plynlimon, Wales, to demonstrate its capabilities.  相似文献