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411.
Andrew Merchant Stefan K. Arndt Douglas M. Rowell Sabine Posch Andrew Callister Michael Tausz Mark A. Adams 《Annals of Forest Science》2010,67(1):104-104
412.
Three methods of automatic classification of leaf diseases are described based on high-resolution multispectral stereo images.
Leaf diseases are economically important as they can cause a loss of yield. Early and reliable detection of leaf diseases
has important practical relevance, especially in the context of precision agriculture for localized treatment with fungicides.
We took stereo images of single sugar beet leaves with two cameras (RGB and multispectral) in a laboratory under well controlled
illumination conditions. The leaves were either healthy or infected with the leaf spot pathogen Cercospora beticola or the rust fungus Uromyces betae. To fuse information from the two sensors, we generated 3-D models of the leaves. We discuss the potential of two pixelwise
methods of classification: k-nearest neighbour and an adaptive Bayes classification with minimum risk assuming a Gaussian mixture model. The medians of
pixelwise classification rates achieved in our experiments are 91% for Cercospora beticola and 86% for Uromyces betae. In addition, we investigated the potential of contextual classification with the so called conditional random field method,
which seemed to eliminate the typical errors of pixelwise classification. 相似文献
413.
Vijai Bhadauria Sabine Banniza Li-Xia Wang Yang-Dou Wei You-Liang Peng 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(1):81-95
Proteomics, the systematic analysis of the proteome, is a powerful tool in the post-genomic era. Proteomics studies have examined
global changes in proteomes of phytopathogenic fungi, oomycetes and their hosts during compatible or incompatible interactions.
This article compiles proteomics reports in order to decipher the molecular mechanisms underlying fungal development (infection-related
morphogenesis), fungal or oomycete—host plant interactions, and phytopathogenesis. 相似文献
414.
No diurnal variation in rate or carbon isotope composition of soil respiration in a boreal forest 总被引:1,自引:0,他引:1
Characterization of soil respiration rates and delta(13)C values of soil-respired CO(2) are often based on measurements at a particular time of day. A study by Gower et al. (2001) in a boreal forest demonstrated diurnal patterns of soil CO(2) flux using transparent measurement chambers that included the understory vegetation. It is unclear whether these diurnal patterns were solely the result of photosynthetic CO(2) uptake during the day by the understory or whether there were underlying trends in soil respiration, perhaps driven by plant root allocation, as recently demonstrated in Mediterranean oak savannah. We undertook intensive sampling campaigns in a boreal Picea abies L. Karst. forest to investigate whether diurnal variations in soil respiration rate and stable carbon isotope ratio (delta(13)C) exist in this ecosystem when no understory vegetation is present in the measurement chamber. Soil respiration rates and delta(13)C were measured on plots in which trees were either girdled (to terminate the fraction of soil respiration directly dependent on recent photosynthate from the trees), or not girdled, every 4 h over two 48-hour cycles during the growth season of 2004. Shoot photosynthesis and environmental parameters were measured concurrently. No diurnal patterns in soil respiration rates and delta(13)C were observed in either treatment, despite substantial variations in climatic conditions and shoot photosynthetic rates in non-girdled trees. Consequently, assessment of daily soil respiration rates and delta(13)C in boreal forest systems by single, instantaneous daily measurements does not appear to be confounded by substantial diurnal variation. 相似文献
415.
Cetacean occurrence,habitat preferences and potential for cetacean–fishery interactions in Iberian Atlantic waters: results from cooperative research involving local stakeholders 下载免费PDF全文
Sabine Goetz Fiona L. Read Marisa Ferreira Julio Martínez Portela Maria Begoña Santos José Vingada Ursula Siebert Ana Marçalo Jorge Santos Hélder Araújo Silvia Monteiro Mara Caldas Marcos Riera Graham J. Pierce 《水产资源保护:海洋与淡水生态系统》2015,25(1):138-154
416.
Sabine H. G. Stenkamp Manuel S. Becker Bernd H. E. Hill Rolf Blaich Astrid Forneck 《Euphytica》2009,165(1):197-209
This project studied the genetic variation of the periclinal grape chimera Pinot Meunier, its natural occurring mutations
(loss of trichomes on leaf surfaces) and the German Pinot noir clone Samtrot. Eleven Pinot Meunier clones of French, Italian
and foremost German origin, Pinot Meunier mutations of differing ages and with various dispersions of hairless sectors as
bud-, shoot- and complete vine mutations and six Samtrot clones were investigated with amplified fragment length polymorphisms
(AFLPs) and microsatellites (SSRs). SSR-analysis proved chimerism of all Pinot Meunier clones tested and confirmed identical
genotype for all hairless mutations and Samtrot clones at the analyzed loci. Clonal variation was shown by AFLP-analysis yielding
a total of 670 bands out of 18 primer combinations of which 161 were polymorphic. Pinot Meunier, Samtrot and the naturally
occurring hairless Pinot Meunier mutations could be significantly differentiated. Most of interclonal varying AFLP fragments
(mean 1.5% per sample) originated within the groups of Samtrot or Pinot Meunier mutations, whereas intraclonal identity was
highest within the Pinot Meunier clones. According to the analysis of molecular variance (AMOVA), variation among wild type
and mutated Pinot Meunier leaf halves is significantly smaller than between phenotypically identical Samtrot and Pinot Meunier
mutants. Average gene diversity calculated on variability of loci reduced from Samtrot (0.040 ± 0.023) towards Pinot Meunier
(0.025 ± 0.013) clones. 相似文献
417.
Linseisen J Rohrmann S Norat T Gonzalez CA Dorronsoro Iraeta M Morote Gómez P Chirlaque MD Pozo BG Ardanaz E Mattisson I Pettersson U Palmqvist R Van Guelpen B Bingham SA McTaggart A Spencer EA Overvad K Tjønneland A Stripp C Clavel-Chapelon F Kesse E Boeing H Klipstein-Grobusch K Trichopoulou A Vasilopoulou E Bellos G Pala V Masala G Tumino R Sacerdote C Del Pezzo M Bueno-de-Mesquita HB Ocke MC Peeters PH Engeset D Skeie G Slimani N Riboli E 《Public health nutrition》2006,9(4):449-464
418.
419.
Biogas plants in Germany are producing an increasing amount of biogas residues to be recycled via agricultural crop production. To test whether the wide range of various substrates used in the anaerobic digestion can affect the chemical composition and nutrient availability, seven biogas residues derived from different substrates were investigated with respect to their N supply to ryegrass. Both the short‐term and the long‐term N availability were studied in a 309‐d pot experiment lasting for five successive growth cycles each starting with a fertilizer application. The organic fertilizers were applied based on an equal amount of ammonium‐N (300 mg N per pot) and compared to mineral N from ammonium nitrate of equal dosage. Biogas residues varied greatly in their chemical composition (ammonium‐N 0.20% to 0.51%, Ntotal 0.36% to 0.75%, and Corg 1.85% to 4.75% in fresh matter). After the first growth cycle, the N availability of the biogas residues applied based on ammonium‐N was at least equal to that from ammonium nitrate. Differences in N offtake after one fertilizer application were negatively correlated to the Corg : Norg ratio of the organic fertilizers. After five successive fertilizer applications, the N utilization of most of the organic fertilizers was increased compared to that of the mineral fertilizer. It is concluded that biogas residues provide plant‐available N at least corresponding to their ammonium content and that the accumulation of organic N in soil through repeated application of biogas residues contributes to N release. 相似文献
420.
Complex soil microbial data produced by molecular profiling techniques, such as terminal restriction fragment length polymorphism (T-RFLP), are often analysed using multivariate statistical methods. Despite this, there has been little evaluation of the sensitivity of multivariate methods to routine data manipulations such as the application of noise thresholds. We examine effects of three percentage area thresholds (0.1%, 0.5% and 1.0%; i.e. ranging from low to commonly applied) on non-metric multidimensional scaling (NMDS) ordinations of soil fungal T-RFLP profiles. We then interpret threshold effects by introducing the concept of structural redundancy in T-RFLP data.NMDS ordinations compared 20 soil samples (encompassing seven sites, two forest types, and three locations) for T-RFLP presence/absence data, which were produced using primers specific to the rDNA internal transcribed spacer (ITS) region, and three separate restriction enzymes (HinfI, AluI and TaqI). Increasing thresholds from 0.1% to 1.0% led to decreases in average number of detected reproducible fragments per site of 57% (HinfI), 75% (AluI), and 69% (TaqI). However, despite the removal of many fragments unique to site/forest type/location, the application of increasing thresholds did not significantly change NMDS patterns for any enzyme in both the complete data and in a more weakly structured sub-group (involving one forest type and two locations). Thus, our data indicate that application of area thresholds up to 1.0% would have minimal impact on NMDS-based comparisons of soil fungal composition.Robustness of NMDS patterns to considerable fragment loss with increasing threshold suggested a degree of ‘structural redundancy’ in our T-RFLP data – that is, multiple fragments per soil sample were interchangeable in the way they contributed to between-sample NMDS patterns. Indeed, for each restriction enzyme, we found 3–4 peels of data (i.e. mutually exclusive sub-sets) that were capable of reproducing overall patterns in presence/absence data at the 0.1% threshold. Despite potential in the T-RFLP method for production of more than one fragment per fungal species/phylotype, we present arguments to support at least some translation of structural redundancy in T-RFLP data to structural redundancy in fungal community comparisons (i.e. the between-soil similarity patterns can be explained by, or are imprinted in, multiple groups of fungal phylotypes). Our analyses highlight structural redundancy as an efficient method for identifying key phylotypes responsible for differences in community composition among soils, and as a promising starting point for improved understanding of many aspects of spatial soil ecology. 相似文献