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91.
Top down preselection using marker assisted estimates of breeding values in dairy cattle 总被引:1,自引:0,他引:1
Jörn Bennewitz Norbert Reinsch Friedrich Reinhardt Zengting Liu Ernst Kalm 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2004,121(5):307-318
Top down preselection of young bulls before entering progeny testing has been proposed as a practicable form of marker‐assisted selection (MAS), especially in dairy cattle populations with large male paternal half‐sib families. Linkage phase between the superior (Q) and the inferior (q) QTL alleles of heterozygous sires (Qq at the QTL) with informative markers is established within each paternal half‐sib family and may be used for selection among grand‐progeny. If, additionally to sires, bulldams are also genotyped and data from consecutive generations are used, then a marker‐assisted best linear unbiased prediction (MA‐BLUP) model can be employed to connect the information of all generations and families of a top down design, and to select across all families. A customized ‘augmented’ sire model (with sires and dams of sires as random effects) is introduced for this purpose. Adapted formulae for the mixed model equations are given and their equivalence to a corresponding animal model and to a certain variant of previously proposed reduced animal models is shown. The application of the augmented sire model in MA‐BLUP estimation from daughter‐yield deviations and effective daughter contributions is presented. 相似文献
92.
Cheng-Zhi Qin A-Xing Zhu Tao Pei Bao-Lin Li Thomas Scholten Thorsten Behrens Cheng-Hu Zhou 《Precision Agriculture》2011,12(1):32-43
As an important topographic attribute widely-used in precision agriculture, topographic wetness index (TWI) is designed to
quantify the effect of local topography on hydrological processes and for modeling the spatial distribution of soil moisture
and surface saturation. This index is formulated as TWI = ln(a/tanβ), where a is the upslope contributing area per unit contour length (or Specific Catchment Area, SCA) and tanβ is the local slope gradient for estimating a hydraulic gradient. The computation of both a and tanβ need to reflect impacts of local terrain on local drainage. Many of the existing flow direction algorithms for computing
a use global parameters, which lead to unrealistic partitioning of flow. β is often approximated by slope gradient around the pixel. In fact, the downslope gradient of the pixel is a better approximation
of β. This paper examines how TWI is impacted by a multiple flow routing algorithm adaptive to local terrain and the employment
of maximum downslope gradient as β. The adaptive multiple flow routing algorithm partitions flow by altering the flow partition parameter based on local maximum
downslope gradient. The proposed approach for computing TWI is quantitatively evaluated using four types of artificial terrains
constructed as DEMs with a series of resolutions (1, 5, 10, 20, and 30 m), respectively. The result shows that the error of
TWI computed using the proposed approach is generally lower than that of TWI by the widely used approach. The new approach
was applied to a low-relief agricultural catchment (about 60 km2) in the Nenjiang watershed, Northeastern China. The results of this application show that the distribution of TWI by the
proposed approach reflects local terrain conditions better. 相似文献
93.
Marco Heurich Tobias Ochs Thorsten Andresen Thomas Schneider 《European Journal of Forest Research》2010,129(3):313-324
The survey and continuing inventory in the Bavarian Forest National Park of deadwood areas resulting from a spruce bark beetle
calamity are being performed by means of visual evaluation of colour infrared aerial photographs. With the aid of the object-oriented
image analysis software eCognition, it was possible to develop a partially automated method for this purpose. In order to
verify the classification results, a test area was classified, and the results compared with those obtained by the previously
used method. In addition, the classification results from two consecutive years were compared, and accuracy assessment methods
were used to scrutinize the results. Classification in the deadwood areas yielded a total classification accuracy of 91.5%.
In regard to objectivity and degree of detail, the newly developed method is significantly superior to the former method,
which is based on visual interpretation with a stereo workstation. One problem, however, was the insufficient spatial accuracy
of the respective orthophotos. Because of this, it was not possible to detect changes over the course of specified time intervals.
Therefore, a practical application of this method would require that the orthophotos from various dates or times be precisely
spatially assigned. This requirement can be achieved with the production of new orthophotos. 相似文献
94.
德国的森林业和木材工业已经成为面向国际市场的高质量针叶材和阔叶材产品的重要供应者。德国的制材工业与中国保持着欣欣向荣的贸易关系,而中国作为其新兴的贸易伙伴,正在借助现代木材产品的优势来构建一种可持续的生活方式。 相似文献
95.
BACKGROUND: Typical active ingredient (AI) residue patterns are formed during droplet drying on plant surfaces owing to the interaction of spray solution characteristics and leaf micromorphology. Currently, comparatively little is known about the influence of AI deposit patterns within a spray droplet residue area on the penetration and biological efficacy of glyphosate. A scanning electron microscope with energy dispersive X‐ray microanalysis has been used to characterise residue patterns and to quantify the area ultimately covered by glyphosate within the droplet spread area. RESULTS: The easy‐to‐wet weed species Stellaria media L. and Viola arvensis L., as well as the difficult‐to‐wet Chenopodium album L. and Setaria viridis L., differing in their surface micromorphology, have been used. Rapeseed oil ethoxylates (RSO 5 or RSO 60) were added to glyphosate solutions to provide different droplet spread areas. Addition of RSO 5 enhanced droplet spread area more than RSO 60, and both caused distinct glyphosate residue patterns. The biological efficacy of treatment solutions showed no significant correlation with the area ultimately covered by glyphosate. CONCLUSION: The results have implications on herbicide uptake models. This study shows that droplet spread area does not correspond to the area ultimately covered by glyphosate, and that the latter does not affect glyphosate phytotoxicity. Copyright © 2009 Society of Chemical Industry 相似文献
96.
John Kormla Nyameasem Reiner Ruser Christof Kluß Christoph Essich Mareike Zutz Martin ten Huf Caroline Buchen-Tschiskale Heinz Flessa Hans-Werner Olfs Friedhelm Taube Thorsten Reinsch 《Grass and Forage Science》2023,78(3):338-358
The effect of slurry application techniques and slurry N stabilizing strategies on nitrous oxide emission from grasslands is poorly understood and, therefore, can result in large uncertainties in national/regional inventories. Field experiments were, thus, conducted to estimate the effect of different fertilization techniques on nitrous oxide (N2O) emissions. Fertilizer was applied (135–270 kg N ha−1 year−1) as calcium ammonium nitrate (CAN), untreated or treated cattle slurry. The slurry was either treated with sulfuric acid (target pH = 6.0), applied using trailing shoes or treated with 3,4-dimethyl pyrazole phosphate and applied via slot injection. N2O fluxes were sampled using the closed chamber technique. Cumulative N2O emissions ranged 0.1–2.9 kg N ha−1 year−1 across the treatment, sites and years. The N application techniques showed inconsistent effects on soil mineral N content, cumulative N2O emission and N yield. The fertilizer replacement value of slurry was low due to low N use efficiencies at the sites. However, a close positive relationship (r = 0.5; p = .013) between slurry value and biomass yield was observed, highlighting the benefit of high slurry value on crop productivity. N2O-N emission factors were low for all treatments, including CAN, but were 2–6 times higher in 2019 than in 2020 due to lower precipitation in 2020. Variations in N2O emission were largely explained by soil and climatic factors. Even with the low N2O emissions, this study highlights the benefit (significant mitigation of N2O emissions) of replacing the increasingly expensive chemical fertilizer N with input from slurry under favourable conditions for denitrification. 相似文献
97.
Hermann Rodenkirchen Axel Göttlein Alessandra R. Kozovits Rainer Matyssek Thorsten E. E. Grams 《European Journal of Forest Research》2009,128(2):117-128
Saplings of Fagus sylvatica and Picea abies were grown under conditions of intra and interspecific competition in a 2-year phytotron study under combinations of ambient
and elevated ozone (+O3 which is 2 × O3, but <150 nl l−1) as well as carbon dioxide concentrations (+CO2 which is amb. CO2 + 300 μl CO2 l−1) in a full factorial design. Saplings were analysed for various mineral nutrients in different plant organs as well as biomass
production and crown development. The study was based on the assumption that nutritional parameters important for growth and
competitiveness are affected by stress defence under limiting nutrient supply. The hypotheses tested were (1) that nutrient
uptake-related parameters (a) as well as efficiencies in nutrient use for above-ground competition (b) of beech rather than
spruce are impaired by the exposure to elevated O3 concentrations, (2) that the efficiency in nutrient uptake of spruce is enhanced by elevated CO2 concentrations in mixed culture, and (3) that the ability to occupy above-ground space at low nutrient cost is co-determinant
for the competitive success in mixed culture. Clear nitrogen deficiencies were indicated for both species during the 2-year
phytotron study, although foliar nitrogen-biomass relationships were not so close for spruce than for beech. O3 stress did not impair nutrient uptake-related parameters of beech; thus hypothesis (1a). was not supported. A negative effect
of elevated O3 (under amb. CO2) on the N and P based efficiencies in above-ground space occupation (i.e. lower crown volume per unit of N or P invested
in stems, limbs and foliage) of beech supported hypothesis (1b). It appeared that ozone stress triggered a nutrient demand
for stress defence and tolerance at the expense of above-ground competition (trade-off). Crown volume of beech under O3 stress was stabilized in monoculture by increased nutrient uptake. In general, the +CO2-treatment was able to counteract the impacts of 2 × O3. Elevated CO2 caused lower N and S concentrations in current-year foliage of both tree species, slightly higher macronutrient amounts in
the root biomass of spruce, but did not increase the efficiencies in nutrient uptake of spruce in mixed culture. Therefore
hypothesis (2) was not supported. At the end of the experiment spruce turned out to be the stronger competitor in mixed culture
as displayed by its higher total shoot biomass and crown volume. The amounts of macronutrients in the above-ground biomass
of spruce individuals in mixed culture distinctly exceeded those of beech, which had been strongly reduced by interspecific
competition. The superior competitiveness of spruce was related to higher N and P-based efficiencies in above-ground space
occupation as suggested in hypothesis (3).
This article belongs to the special issue “Growth and defence of Norway spruce and European beech in pure and mixed stands”. 相似文献
98.
Elevated concentrations of carbon dioxide ([CO2]) and ozone ([O3]) affect primary metabolism of trees in opposite ways. We studied their potential interactions on carbohydrate concentrations and contents. Two hypotheses currently under debate were tested. (1) Stimulation of primary metabolism by prolonged exposure to elevated [CO2] does not compensate for the adverse effects of O3 on carbohydrate accumulation and biomass partitioning to the root. (2) Growth in a mixed-species planting will repress plant responses to elevated [O3] and [CO2] relative to conditions in a monoculture. To this end, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) saplings grown under conditions of intra- and interspecific competition were pre-acclimated for 1 year to ambient or elevated [CO2]. In the following 2-year phytotron study, trees were exposed to factorial combinations of ambient and elevated [O3] and [CO2]. The total carbohydrate content (sugar and starch) of spruce was greater in plants exposed to elevated [CO2] than in plants exposed to ambient [CO2]. In beech, the opposite response was observed, especially when this species was grown in combination with spruce. Overall, the data did not support Hypothesis 1, because the adverse effects of O3 were counteracted by elevated [CO2]. Support for Hypothesis 2 was species-dependent. In beech saplings, reduction of carbohydrates by elevated [O3] and stimulation by elevated [CO2] were repressed by competitive interaction with spruce. In contrast, in spruce, stimulation of carbohydrates by elevated [CO2] was similar in mono- and mixed cultures. Thus Hypothesis 2 was supported for beech but not spruce. We conclude that, in juvenile beech and spruce, a 3-year exposure to elevated [CO2] counteracts the adverse effects of O3 on carbohydrate concentrations and contents. For beech, sensitivity to elevated [CO2] and [O3] was high in monoculture but was largely repressed by interspecific competition with spruce. In contrast, the response of spruce to perturbations of atmospheric chemistry was not significantly affected by either intra- or interspecific competition. 相似文献
99.
Saxony Lower Richerzhagen Dominique Racca Paolo Zeuner Thorsten Kuhn Christian Falke Kristina Kleinhenz Benno Hau Bernhard 《植物病害和植物保护杂志》2011,118(5):168-177
Journal of Plant Diseases and Protection - The effect of climate change on the temporal and regional occurrence of Cercospora leaf spot (CLS) of sugar beet in Lower Saxony is analysed using the... 相似文献
100.
Helmy M. Youssef Ravi Koppolu Thorsten Schnurbusch 《Genetic Resources and Crop Evolution》2012,59(7):1319-1328
Labile-barleys (Hordeum vulgare convar. labile (Schiem.) Mansf.) are found in the highlands of Ethiopia, Eretria and North India-Pakistan districts. They represent a distinct spike form showing row-type alterations even within individual spikes of the same genotypes. Variation at the six-rowed spike 1 (vrs1) locus is sufficient to control barley lateral spikelet fertility, which is also modified by alleles at the intermedium-c (int-c) locus. This study aimed at re-sequencing these two loci to investigate whether labile-barleys have a two-rowed genetic background, resulting in increased lateral spikelet fertility, or show reduced lateral spikelet fertility if they possess a six-rowed genetic background. The Vrs1 re-sequencing results of 221 supposedly labile-barley accessions from Ethiopia revealed 13 accessions with two novel vrs1.a1 haplotypes. Following the current nomenclature of vrs1 haplotypes, the new haplotypes were named as haplotypes 66 and 67. Re-sequencing at the int-c locus showed that 118 of the labile-barleys possessed the previously described Int-c.a allele but only one accession was found having a novel Int-c.a haplotype in the homozygous state (termed Int-c.a haplotype1; Hap_1). Interestingly, 101 labile-barleys carried the Int-c.a allele and Int-c.a haplotype1 simultaneously, suggesting maintained heterozygosity or recent gene duplication at this locus. Only one accession had a two-rowed haplotype (Vrs1.b3, int-c.b1) and one accession possessed the Vrs1.t (deficiens) and Int-c.a alleles (six-rowed). These two accessions were considered as misclassified labile genotypes and not included in further analysis. Thus, these results confirmed that all of the 219 labile accessions studied in this work showed six-rowed alleles at vrs1 but reduced lateral spikelet fertility. This reduction is most likely caused by the recessive labile (lab) locus which we are in the process to characterize further. 相似文献