Statistical modelling of measurement error in wet chemistry soil data     

Cynthia C. E. van Leeuwen  Vera L. Mulder  Niels H. Batjes  Gerard B. M. Heuvelink 《European Journal of Soil Science》2022,73(1):e13137

  相似文献   

Gas sensor array for blueberry fruit disease detection and classification     

Changying Li  Gerard W. Krewer  Pingsheng Ji  Harald Scherm  Stanley J. Kays 《Postharvest Biology and Technology》2010,55(3):144-149

A conducting polymer gas sensor array (electronic nose) was evaluated for detecting and classifying three common postharvest diseases of blueberry fruit: gray mold caused by Botrytis cinerea, anthracnose caused by Colletotrichum gloeosporioides, and Alternaria rot caused by Alternaria sp. Samples of ripe rabbiteye blueberries (Vaccinium virgatum cv. Brightwell) were inoculated individually with one of the three pathogens or left non-inoculated, and volatiles emanating from the fruit were assessed using the gas sensor array 6–10 d after inoculation in two separate experiments. Principal component analysis of volatile profiles revealed four distinct groups corresponding to the four inoculation treatments. MANOVA, conducted on profiles from individual assessment days or from combined data, confirmed that the four treatments were significantly different (P < 0.0001). A hierarchical cluster analysis indicated two super-clusters, i.e., control cluster (non-inoculated fruit) vs. pathogen cluster (inoculated fruit). Within the pathogen cluster, fruit infected by B. cinerea and Alternaria sp. were more similar to each other than to fruit infected by C. gloeosporioides. A linear Bayesian classifier achieved 90% overall correct classification for data from experiment 1. Tenax? trapping of volatiles with short-path thermal desorption and quantification by gas chromatography–mass spectrometry was used to characterize volatile compounds emanated from the four groups of berries. Six compounds [styrene, 1-methyl-2-(1-methylethyl) benzene, eucalyptol, undecane, 5-methyl-2-(1-methylethyl)-2-cyclohexen-1-one, and thujopsene] were identified as contributing most in distinguishing differences in the volatiles emanating from the fruit due to infection. A canonical discriminant analysis model using the relative concentration of each of these compounds was developed and successfully classified the four categories of berries. This study underscores the potential feasibility of using a gas sensor array for blueberry postharvest quality assessment and fungal disease detection.  相似文献   

Determinants and Utility of the Anion Gap in Predicting Hyperlactatemia in Cattle   总被引：2，自引：0，他引：2  

Peter D. Constable BSc  Phd    Robert N. Streeter  Gerard J. Koenig  Nigel R. Perkins  Hani M. Gohar  Dawn E. Morin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1997,11(2):71-79

The objectives of this study were to investigate the determinants of the anion gap (AG) in cattle and to evaluate the utility of AG in detecting hyperlactatemia in sick neonatal calves and adult cattle. The AG was calculated as AG = ([Na+] + [K+]) - ([Cl^-] + [HCO₃]), with all values in mEq/L. The AG of healthy neonatal calves (n = 16) was 29.6 ± 6.2 mEq/L (mean ± SD), and the blood L-lactate concentration ranged from 0.5 to 1.2 mM/L. The AG was significantly (P > .05) correlated with serum phosphate (r = .66) and creatinine (r = .51) concentrations. The AG of neonatal calves with experimentally induced diarrhea (n = 16) was 28.6 ± 5.6 mEq/L, and the blood L-lactate concentration ranged from 1.1 to 2.9 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .67), serum phosphate concentration (r = .63), creatinine concentration (r = .76), and blood pH (r = -.61). The AG of adult cattle with abomasal volvulus (n = 41) was 20.5 ± 7.8 mEq/L, and the blood L-lactate concentration ranged from 0.6 to 15.6 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .60), serum phosphate concentration (r = .71), creatinine concentration (r = .65), albumin concentration (r = .47), total protein concentration (r = .54), blood pyruvate concentration (r = .67), and blood pH (r = -.41) but not plasma β-OH butyrate concentration. The results indicate that the AG in cattle is only moderately correlated with blood L-lactate concentration and is similarly correlated with serum phosphate and creatinine concentrations in neonatal calves and adult cattle, as well as with serum albumin and total protein concentrations in adult cattle. Anion gap determination is of limited usefulness in predicting blood L-lactate concentration in sick cattle, whereas the correlation between AG and serum creatinine concentration in sick cattle suggests that an increased AG should alert the clinician to the potential presence of uremic anions.  相似文献   

Molecular mapping and characterization of traits controlling fiber quality in cotton   总被引：34，自引：1，他引：34  

Russell J. Kohel  John Yu  Yong-Ha Park  Gerard R. Lazo 《Euphytica》2001,121(2):163-172

Cotton (Gossypium spp) is the world's leading natural fiber crop. Genetic manipulation continues to play a key role in the improvement of fiber quality properties. By use of DNA-based molecular markers and a polymorphic mapping population derived from an inter specific cross between TM-1 (G. hirsutum) and 3-79 (G. barbadense), thirteen quantitative trait loci (QTLs) controlling fiber quality properties were identified in 3-79, an extra long staple (ELS) cotton. Four QTLs influenced bundle fiber strength, three influenced fiber length, and six influenced fiber fineness. These QTLs were located on different chromosomes or linkage groups and collectively explained 30% to 60%of the total phenotypic variance for each fiber quality property in the F₂ population. The effects and modes of action for the individual QTLs were characterized with 3-79 alleles in TM-1 genetic background. The results indicated more recessive than dominant, with much less additive effect in the gene mode. Transgressive segregation was observed for fiber fineness that could be beneficial to improvement of this trait. Molecular markers linked to fiber quality QTLs would be most effective in marker-assisted selection (MAS) of these recessive alleles in cotton breeding programs. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Effects of CO2 enrichment on young plant growth of 96 genotypes of tomato (Lycopersicon esculentum)     

Pim Lindhout  Gerard Pet 《Euphytica》1990,51(2):191-196

Summary The early growth of 96 genotypes of tomato was studied at 320 ppm CO₂ and at 750 ppm CO₂ in separate climate rooms. Plants were harvested at 40 and 55 days after sowing. Fresh and dry weights were determined. Large differences between genotypes were found for average plant fresh and dry weights and for relative growth rates. The average overall growth enhancement by CO₂ enrichment was 2.3. Two genotypes showed significant genotype x CO₂ interaction. The consequences of these results for tomato breeding are discussed.  相似文献   

Genetic mapping in Lilium: mapping of major genes and quantitative trait loci for several ornamental traits and disease resistances     

Arwa Shahin  Paul Arens  Adriaan W. Van Heusden  Gerard Van Der Linden  Martijn Van Kaauwen  Nadeem Khan  Henk J. Schouten  W. Eric Van De Weg  Richard G. F. Visser  Jaap M. Van Tuyl 《Plant Breeding》2011,130(3):372-382

  相似文献   

In vitro screening and QTL analysis for drought tolerance in diploid potato     

A. M. Anithakumari  Oene Dolstra  Ben Vosman  Richard G. F. Visser  C. Gerard van der Linden 《Euphytica》2011,181(3):357-369

Drought stress is a major abiotic constraint limiting crop production worldwide. Screening for drought tolerance and the traits that enhance drought tolerance is not straightforward in large mapping populations. In this study, we investigated the possibility of screening a mapping population in vitro for PEG-induced water deficit stress and recovery potential. We have measured several shoot and root growth parameters or traits in the C × E diploid potato mapping population. Significant variation was observed for genotype-specific responses to water deficit and recovery potential. Genetic variation and heritability estimates were high to very high for the measured traits depending on growth conditions. In order to identify potato QTLs for drought tolerance and recovery potential an SNP marker-rich integrated linkage map was used. A total of 23 QTLs were detected under control, stress and recovery treatments explaining 10.3–22.4% of the variance for each phenotypic trait. Among these, 10 QTLs were located on chromosome 2. Three QTLs involved in the important trait root to shoot ratio were identified on linkage groups 2, 3 and 8. These loci explained together 41.1% of the variance for this trait, and may be breeding targets for stress tolerance and yield in the field as well. The SNP markers derived from EST sequences underlying these QTLs led to the identification of putative candidate genes for further study in potato. This study constitutes the first knowledge of in vitro screening of a mapping population for drought tolerance in potato.  相似文献   

Greenhouse evaluation and inheritance analysis of transgenic cotton expressing <Emphasis Type="Italic">PTM3</Emphasis>, a MADS-box gene of Aspen     

Esakky Ramachandran  Suchit Ashish John  Gerard Abraham  Partha Sarathi Bhattacharya 《Journal of Crop Science and Biotechnology》2011,14(4):275-279

The PTM3 (MADS-box) gene characterized from flower of Aspen was ectopically expressed in cotton and was found to result in desirable agronomic traits. Among several transgenic lines, the PTM3 cotton event-10 was found to flower significantly earlier than the control and yield better [Ramachandran et al. (2011)]. We report our findings on performance based on greenhouse evaluation and inheritance of PTM3 cotton event-10. The T₁ progeny of event-10 were grown in pots under RBD design. The progeny were confirmed by kanamycin imbibition test, PCR, and GUS assay which showed the segregation of transgene at about 3:1 ratio. GUS assay was performed with pollen from all transgenic plants; plants that expressed gus in all pollen versus those that showed segregation for expression were found to be at a ratio of 1:2. Similar to observations made in the T₀ generation of event-10, the agronomic evaluation of T₁ progeny exhibited, on an average, earliness of 13 days in flowering, 13.5 days in crop maturity, and 22% of yield enhancement. The T₂ progeny of homozygous lines were grown on field soil in the greenhouse under strip trial design to see the effect as observed from potted plants of T₁ progeny. Inheritance of transgene cassette to T₂ progeny was confirmed by the same tests used to analyze T₁ progeny. As exhibited by T₀ and T₁ progenies, the T₂ progeny also showed earliness of 8 days in flowering, 12 days in crop maturity, and 17% of yield enhancement. The data generated from the progeny over two generations confirms that the PTM3 cotton event-10 is superior in agronomic characters as compared to non-transgenic cotton and is of interest for breeding shorter duration varieties with improved yield.  相似文献   

Developments in indoor sustainable plant production with emphasis on energy saving   总被引：1，自引：0，他引：1  

Gerard P. A. Bot   《Computers and Electronics in Agriculture》2001,30(1-3)

In conventional greenhouse crop production the high level of energy input conflicts with international agreements on reduction of CO₂ emission. To reduce absolute energy consumption, energy friendly greenhouse systems have to be designed. If today's available technology is applied energy saving will be too low to meet the standards in future. Therefore, new technology has to be developed on aspects ranging from improving the greenhouse insulation and light transmittance to climate conditioning and control and energy management. An important aspect is that the production system is converted from a production-driven to a consumer-oriented activity. Modelling and information technology are important aspects in the developments in interaction with other disciplines.  相似文献   

Why is climate sensitivity so unpredictable?     

Roe GH  Baker MB 《Science (New York, N.Y.)》2007,318(5850):629-632

Uncertainties in projections of future climate change have not lessened substantially in past decades. Both models and observations yield broad probability distributions for long-term increases in global mean temperature expected from the doubling of atmospheric carbon dioxide, with small but finite probabilities of very large increases. We show that the shape of these probability distributions is an inevitable and general consequence of the nature of the climate system, and we derive a simple analytic form for the shape that fits recent published distributions very well. We show that the breadth of the distribution and, in particular, the probability of large temperature increases are relatively insensitive to decreases in uncertainties associated with the underlying climate processes.  相似文献