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161.
Near-infrared reflectance spectroscopy has been applied for the first time to saffron spice to determine the chemical composition and geographical origin of 111 samples from the there main producers' countries: Iran, Greece, and Spain. The validation procedures with the results obtained by UV-vis and HPLC-DAD measurements demonstrated that this technique is appropriate to determine the following parameters: moisture and volatile content, coloring strength, (250 nm), and (330 nm), established on the ISO 3632 Technical Specification Normative and used to certify saffron quality in the international market. Also, it can be used to estimate the content of the five main crocetin glycosides, the compounds responsible for saffron color, the best correlations being for trans-crocetin di-(beta-D-gentibiosyl) ester (R2= 0.93), trans-crocetin (beta-D-glucosyl)-(beta-D-gentibiosyl) (R2= 0.94), and picrocrocin (R2= 0.92), the compound accepted as responsible for saffron bitterness. Finally, a discriminant analysis among the three geographical origins reveals that Iranian samples are the most different, whereas Greek and Spanish samples are more similar. All of these results reveal that NIRS spectroscopy has an enormous potential for its application to saffron quality control as the results are obtained in 2 min and without any sample manipulation.  相似文献   
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163.
Agro-biodiversity is currently experiencing severe genetic erosion due to mankind’s unsustainable activities. Because of initiatives following the goal of the conservation of biological diversity, so far seven million crop accessions are being conserved ex situ in gene banks worldwide. Many of these accessions are landraces being rich in gene diversity, silently awaiting their proper characterisation. This is a very critical part of any long-term strategy to enhance the productivity and resilience of crops and agricultural systems and—most importantly—to ensure the preservation of our cultural and biological heritage. In this study of an ex situ germplasm evaluation we analysed 27 flax (Linum usitatissimum L.) accessions originating in the Alpine region, provided by five local gene banks/providers. Based on genomic microsatellite markers (gSSRs), a varying extent of accession-specific gene diversity (expected heterozygosity, HE) was revealed ranging from 0.05 to 0.51. Admixture of individuals between accessions was uncovered, pointing towards past processes related to gene bank management activities (e.g. intentional selection, unintentional cross-pollination during regeneration) or towards the evolution of the landrace itself (e.g. same regional origin, traditional naming), highlighting the co-existence of cultural and biological diversity. Such an genetic analysis of accessions stored ex situ not only produces valuable agronomic and breeding data, but also is useful for the clarification of past processes leading to duplicates within and between collections or mislabelling, contributing to the potential for rationalisation of collections, which in turn can help ensure that the limited resources available for regeneration are used most efficiently and effectively.  相似文献   
164.
We have previously found an accession of Lycopersicon pimpinellifolium (Jusl.) Mill. (`TO-937') that appeared to resist attack by the two-spotted spider mite (Tetranychus urticae Koch). L. pimpinellifolium is a very close relative of the cultivated tomato (Lycopersicon esculentum Mill.) and thereby a potential source of desirable traits that could be introgressed to the crop species. The objective of this study was to investigate the genetics of the resistance present in `TO-937'. Resistance to infestation by the spider mite was quantified in 24-plant plots of L. pimpinellifolium accessions `TO-937' and `PE-10', L. pennellii accession `PE-45', L. esculentum cultivars `Moneymaker', `Roma' and `Kalohi' (reported to be partially resistant: Stoner & Stringfellow, 1967), and the interspecific F1 cross, L. esculentum `Moneymaker' × L. pimpinellifolium `TO-937'. Only `TO-937', the F1, and`PE-45' were found to be resistant. Resistance of `TO-937' was complete when evaluated in two small greenhouses completely planted with `TO-937' so as to simulate the genotypic homogeneity usual in commercial crops. Generations (P1, P2, F1, F2, BC1P1, and BC1P2) of a P1 (susceptible) × P2 (resistant) cross (`Moneymaker' × `TO-937') were studied for resistance in a single-plant per plot design. Resistance of `TO-937' was inherited with complete dominance and appeared to be controlled by either two or four genes according to whether segregation in the F2 or the BC1P1, respectively, were considered. However, calculation of the number of genes involved in the resistance was complicated by negative interplot interference due to the high frequency of resistant genotypes within most of the generations. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
165.
The climate change will contribute drought and temperature extremes to rice growing systems, especially when cultivated in equatorial regions. To evaluate opportunities to cultivate and breed drought-tolerant rice, seven rice cultivars were evaluated in Rwanda for recurring morphological drought scores, grain yield and components, and quality characteristics. The cultivation conditions, that is site and drought treatment, impacted morphological drought scores, growth and yield attributes, while cultivar affected quality attributes. Thus, site showed a higher impact on grain yield and components than drought and cultivar, with generally a reduced grain yield at the low-temperature site, as a result of low spikelet fertility. Morphological drought scores were generally increased by drought, while drought at the reproductive stage at the high-temperature site was negative for yield and its components. The cultivars “Intsindagirabigega” and “Jyambere” were adapted to high-temperature site conditions. The cultivar “Intsindagirabigega” had the highest amylose content, and “Mpembuke,” the highest antioxidant capacity. Thus, climate change with increased temperature and drought extremes may increase rice productivity in cool areas, while especially drought at reproductive stage will be detrimental in low altitude areas with high temperature. Cultivar variation indicated opportunities for selection and breeding of climate change tolerant rice cultivars which should be of immediate priority.  相似文献   
166.
In this study, La Rioja wine terroir was investigated by the use of (1)H NMR metabolomics on must and wine samples. Rioja is a small wine region in central northern Spain which can geographically be divided into three subareas (Rioja Alta, Rioja Baja, and Rioja Alavesa). The winemaking process from must, through alcoholic and malolactic fermentation, was followed by NMR metabolomics and chemometrics of nine wineries in the Rioja subareas (terroirs). Application of interval extended canonical variate analysis (iECVA) showed discriminative power between wineries which are geographically very close. Isopentanol and isobutanol compounds were found to be key biomarkers for this differentiation.  相似文献   
167.
Fire and fire management are recognized as important factors in biodiversity conservation. Measuring species-level demographic, behavioural and population responses to different fire regimes is essential for designing adequate management policies. Here we assessed the impact of fire on survival rates, reproduction and movement patterns in Testudo graeca, an endangered terrestrial tortoise inhabiting the Mediterranean region, a system in which fire plays a relevant role in the functioning of their ecosystems. Then we predicted the probabilities of quasi-extinction of T. graeca under several fire regimes and population sizes by means of stochastic population models. Our results showed that fire caused direct and delayed reductions in local survival, young individuals being the most affected. There were not differences in fecundity and movement patterns of tortoises between burned and unburned areas. Population models showed a strong variation in the probability of quasi-extinction of populations depending on the fire regime and the population size. Under fire frequencies similar to those occurring in the wild (<1 fire every 20–30 years) most tortoise populations seemed to buffer the effects of fires. However, when this threshold value of fire frequency was surpassed, the probability of quasi-extinction of populations exploded for all populations, except for those with the largest sizes. T. graeca populations may be able to cope with natural current fire frequencies, but the effects of more recurrent fires may severely threaten the species. Our results have straightforward applications for fire management purposes in those areas of the Mediterranean region where this endangered species is present.  相似文献   
168.
Abstract

The main objective of this work was to determine whether nitrogen-use efficiency was affected by the application of different forms (iodide vs iodate) and dosages (20, 40 and 80 µM) of iodine, to ascertain the influence of this trace element in a biofortification programme in lettuce plants. The parameters analysed were root and shoot biomass, nitrate concentration, and organic and total nitrogen as well as those defining nitrogen-use efficiency in plants: total nitrogen content, total nitrogen accumulation, nitrogen-uptake efficiency and nitrogen-utilization efficiency. In addition to decreasing shoot biomass, iodide treatments reduced leaf levels of nitrates, organic nitrogen, and total nitrogen content. Iodate treatments did not affect the concentration of nitrogen in its different forms. The application of iodide caused total nitrogen accumulation and nitrogen-uptake efficiency to decrease, iodate application improved the latter. Both iodide and iodate applications significantly improved nitrogen-utilization efficiency in comparison to the control. The results obtained show that iodate application rates of 40 µM or lower significantly improved all nitrogen parameters analysed, making it possible to increase lettuce productivity and quality.  相似文献   
169.
Sensor technology represents a relatively novel opportunity for water quality monitoring, and some of its many potential uses have been explored and assessed in this paper. Four Norwegian case studies with sensor recordings of turbidity, pH, conductivity and water level have been used for this assessment. The cases have included rivers, creeks and storm water overflow systems, with both point- and non-point sources of pollution from different types of land use including agriculture, road construction works, road salt application and acidic bedrocks. The results indicated that: (1) good correlations were found between sensor-based turbidity data and concentrations of both suspended particulate matter and phosphorus in grab samples from a small agricultural stream; (2) sensor recordings of turbidity proved superior to both fortnightly grab sampling and time-integrated composite sampling in terms of detecting high values of suspended sediments from both diffuse and point sources. However, the calculation of average concentrations based on fortnightly grab samples and sensor data gave almost similar results; (3) at a road construction site, the use of equipment with multiple sensors revealed that anticipated cause and effect relationships between fish deaths and high sediment loads could not be detected, but episodes of low pH of 5–5.5 did occur during rainstorms, probably as a result of weathering of acidic bedrock; and (4) in an urban road system subject to salt application in the wintertime, sensor technology revealed short-term peaks of salinity, on occasions as high as for sea water. Overall, these findings have demonstrated the usefulness of sensor data compared to traditional methods, in particular due to the possibility of high-frequency recordings of several parameters in systems with rapid changes in water quality.  相似文献   
170.
Summary In former Czechoslovakia virulence of rusts attacking wheat was studied since the sixties. Since the same time genes for resistance in the registered cultivars were identified. The role of Berberis and Thalictrum as alternate hosts for stem rust and leaf rust, respectively, was investigated as well. Determined changes of virulence in rust populations could only partially be ascribed to changes of resistance genes in the grown cultivars. Unnecessary genes for virulence had no negative effect on the fitness of the pathogen. All tested samples of aeciospores from barberries attacked rye, not wheat. None of Thalictrum species occurring in the Czech and Slovak Republics was found to host wheat leaf rust. However, the sexual stage of wheat stem rust and wheat leaf rust could be induced on Berberis vulgaris and Thalictrum speciosissimum, respectively. General epidemiological conclusions are drawn from the results and experience of the last 35 years.  相似文献   
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