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971.
Cheng Z Su L Moore J Zhou K Luther M Yin JJ Yu LL 《Journal of agricultural and food chemistry》2006,54(15):5623-5629
This research evaluated the effects of postharvest treatment and heat stress on the availability of wheat antioxidants using Ankor and Trego wheat varieties. The grain, bran, and 40-mesh bran samples of both Ankor and Trego wheat were kept at 25, 60, and 100 degrees C for 9 days. Samples taken at day 0, 1, 2, 3, 5, and 9 were extracted with pure ethanol and examined for antioxidant properties including the scavenging activity against peroxyl (ORAC), cation ABTS, and 2,2-diphenyl-1-picryhydrazyl (DPPH.) radicals, as well as total phenolic content (TPC) and phenolic acid composition. Both heat stress and postharvest treatment significantly altered the antioxidant properties of wheat grain fractions. The ORAC values of Ankor bran and corresponding 40-mesh bran samples kept at 100 degrees C for 9 days reduced to 61 and 40% of that at day 0 on a per dry weight basis, respectively, while the ORAC values of the grain samples showed no significant change. The overall loss of DPPH. scavenging capacity was 38 and 100% for the bran and 40-mesh Ankor bran samples, respectively, and was 47 and 60% in the bran and 40-mesh Trego bran samples, respectively, whereas no reduction was detected in the grain samples under the same heat stress. Heat stress and postharvest treatment had similar effects on ABTS.+ scavenging capacities and TPC values of grain and fractions of both varieties. These data suggest that whole grain as opposed to its fractions is a preferred form of long-term storage for better preserving natural antioxidants and that the reduction of the particle size may accelerate the loss of natural antioxidants in wheat bran during storage and thermal processing but may enhance the releasable amount of wheat antioxidants from bran. 相似文献
972.
Hernán Laurentin 《Genetic Resources and Crop Evolution》2009,56(2):277-292
Characterizations of plant genetic resources based on molecular markers have been increased in the last years. Studies using
a broad range of markers applied on hundreds of plant species are the theoretical basis for inferring genetic diversity to
propose both breeding and conservation strategies. Despite increased importance of molecular characterization in plant genetic
resources, there is scarce information about analysis of this type of data. To fill this gap of information, this review discuss
the rationale behind analyses achieved to study genetic relationship among accessions (within and between groups) and to identify
accession, and also discuss the adequacy of some analyses and/or parameters for specific purposes. Genetic diversity within
groups may be either quantified for the whole group (parameters to choose will depend on type of marker), or quantified and
visualized for the relationships among individuals. Quantification parameters will be chosen depending on type of marker,
reproduction mode and relatedness of individuals. Visualization is achieved by hierarchical and non-hierarchical methods.
Genetic diversity between groups should be quantified either by analysis of molecular variance, or Nei’s parameters, or Wright’s
F-statistics. Efficiency of accession identification can be evaluated by maximal probability of identical match by chance
and number of resolved genotypes. 相似文献
973.
松材线虫危害后马尾松林土壤氮素的矿化特性 总被引:1,自引:0,他引:1
选择合肥大蜀山森林公园受松材线虫危害程度不同的马尾松林为研究对象,采用室内模拟试验对林氮素的转化性质,增加了土壤氮素淋失的危险性。地土壤氮素矿化特征进行了研究。结果表明:不同林分土壤氮素转化速率差异显著(P<0.05),受损严重的林分氮素矿化速率显著高于轻度受损林分,特别是硝化速率更为显著(P<0.01)。松材线虫病危害改变了马尾松林土壤 相似文献
974.
Toghyani M Toghyani M Shahryar HA Zamanizad M 《Tropical animal health and production》2011,43(6):1183-1189
The objective of this study was to evaluate the effects of two methods of early-age water restriction on performance, some
immune responses, serum metabolites, and prevalence of leg weakness in broiler chicks. One-hundred-eighty-seven-day-old chicks
(Ross 308) were allocated to three treatments with four replicates based on a completely randomized design. Treatments included
the control group, where birds had free access to water, and water-restricted groups, where access to water was limited to
three 2-h periods (WRT1) or a 12-h period (WRT2) per day from days 7 to 17. Chicks in the control group were significantly
heavier (P < 0.05) at 17 and 46 days of age compared to the restricted birds. In the WRT2 group, feed intake decreased significantly
over the 17- to 28-day period while feed conversion ratio was poorer during water restriction (P < 0.05). Antibody titers against Newcastle and SRBC were higher (P < 0.05) for chicks with ad libitum access to water. Birds in the restricted groups exhibited a higher heterophil to lymphocyte
ratio compared to the control group (P < 0.05). The treatments had no significant impact on serum metabolites including protein, triglyceride, total cholesterol,
high-density lipoprotein and low-density lipoprotein cholesterols, calcium, and phosphorus concentrations. Walking ability,
tibial dyschondroplasia, foot pad, hock burn, and valgus/varus angulation were not significantly influenced by water restriction.
In conclusion, the current results indicate that early-age water restriction negatively influenced productive traits and immunological
responses of broiler chicks and failed to have any favorable impacts on leg health. 相似文献
975.
Recently, canopy transpiration (Ec) has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to the capacitive exchange between the transpiration stream and stem water storage. Significant errors will be introduced in canopy conductance (gc) and canopy transpiration estimation if the time lag is neglected. In this study, a cross-correlation analysis was used to quantify the time lag, and the sap flow-based transpiration was measured to parameterize Jarvis-type models of gc and thus to simulate Ec of Populus cathayana using the Penman–Monteith equation. The results indicate that solar radiation (Rs) and vapor pressure deficit (VPD) are not fully coincident with sap flow and have an obvious lag effect; the sap flow lags behind Rs and precedes VPD, and there is a 1-h time shift between Ec and sap flow in the 30-min interval data set. A parameterized Jarvis-type gc model is suitable to predict P. cathayana transpiration and explains more than 80% of the variation observed in gc, and the relative error was less than 25%, which shows a preferable simulation effect. The root mean square error (RMSEs) between the predicted and measured Ec were 1.91 × 10?3 (with the time lag) and 3.12 × 10?3 cm h?1 (without the time lag). More importantly, Ec simulation precision that incorporates time lag is improved by 6% compared to the results without the time lag, with the mean relative error (MRE) of only 8.32% and the mean absolute error (MAE) of 1.48 × 10?3 cm h?1. 相似文献
976.
Winfried Schröder Stefan Nickel Simon Schönrock Roman Schmalfuß Werner Wosniok Michaela Meyer Harry Harmens Marina V. Frontasyeva Renate Alber Julia Aleksiayenak Lambe Barandovski Oleg Blum Alejo Carballeira Maria Dam Helena Danielsson Ludwig De Temmermann Anatoly M. Dunaev Barbara Godzik Katrin Hoydal Zvonka Jeran Gunilla Pihl Karlsson Pranvera Lazo Sebastien Leblond Jussi Lindroos Siiri Liiv Sigurður H. Magnússon Blanka Mankovska Encarnación Núñez-Olivera Juha Piispanen Jarmo Poikolainen Ion V. Popescu Flora Qarri Jesus Miguel Santamaria Mitja Skudnik Zdravko Špirić Trajce Stafilov Eiliv Steinnes Claudia Stihi Ivan Suchara Lotti Thöni Hilde Thelle Uggerud Harald G. Zechmeister 《Annals of Forest Science》2017,74(2):31
Key message
Moss surveys provide spatially dense data on environmental concentrations of heavy metals and nitrogen which, together with other biomonitoring and modelling data, can be used for indicating deposition to terrestrial ecosystems and related effects across time and areas of different spatial extension.Context
For enhancing the spatial resolution of measuring and mapping atmospheric deposition by technical devices and by modelling, moss is used complementarily as bio-monitor.Aims
This paper investigated whether nitrogen and heavy metal concentrations derived by biomonitoring of atmospheric deposition are statistically meaningful in terms of compliance with minimum sample size across several spatial levels (objective 1), whether this is also true in terms of geostatistical criteria such as spatial auto-correlation and, by this, estimated values for unsampled locations (objective 2) and whether moss indicates atmospheric deposition in a similar way as modelled deposition, tree foliage and natural surface soil at the European and country level, and whether they indicate site-specific variance due to canopy drip (objective 3).Methods
Data from modelling and biomonitoring atmospheric deposition were statistically analysed by means of minimum sample size calculation, by geostatistics as well as by bivariate correlation analyses and by multivariate correlation analyses using the Classification and Regression Tree approach and the Random Forests method.Results
It was found that the compliance of measurements with the minimum sample size varies by spatial scale and element measured. For unsampled locations, estimation could be derived. Statistically significant correlations between concentrations of heavy metals and nitrogen in moss and modelled atmospheric deposition, and concentrations in leaves, needles and soil were found. Significant influence of canopy drip on nitrogen concentration in moss was proven.Conclusion
Moss surveys should complement modelled atmospheric deposition data as well as other biomonitoring approaches and offer a great potential for various terrestrial monitoring programmes dealing with exposure and effects.977.
采用未处理和溴甲烷熏蒸处理土壤为对照,研究原美草莓重茬病防治剂不同剂量,对大棚重茬草莓根际土壤真菌、放线菌、细菌数量和种类的影响。拟证实原美防治剂的生态安全性和土壤处理效果,确定其有效剂量。试验结果表明:在各不同处理和不同生育期(初花期、盛花期和采果后期),防治剂处理A3(150g/m2)根际土壤真菌、细菌、放线菌数量高于未处理、溴甲烷处理和其它浓度处理,充分提高土壤肥力。草莓产量比溴甲烷处理提高33.6%,比对照提高388.9%。因此认定原美重茬防治剂对草莓生产比溴甲烷处理效果好得多,其有效剂量为150g/m2。同时从不同处理的根际土壤中经分离、纯化得到10个纯真菌菌株,通过形态学特征初步鉴定以疫霉属为优势菌属。 相似文献
978.
Masatomi Hosoi Chuya Shinzato Masaya Takagi Shoko Hosoi-Tanabe Hideki Sawada Eri Terasawa Haruhiko Toyohara 《Fisheries Science》2007,73(2):385-394
ABSTRACT: Taurine is the primary osmolyte in marine molluscs, whose cellular osmo-conforming process is vital for environmental adaptation because of a lack of osmotic homeostasis. Here, cDNA cloning and expression, and functional analyses of taurine transporter (TAUT) from the giant Pacific oyster are reported on. The deduced amino-acid sequence of oyster TAUT (oyTAUT) showed 47–51% identity to those of vertebrate TAUT, whereas identity among the vertebrates is 78–95%. Functional analysis of oyTAUT expressed in Xenopus oocytes revealed that oyTAUT has a lower affinity and specificity for taurine and a requirement for higher NaCl concentration, compared with vertebrate TAUT. Taken together with similar functional properties of TAUT from mussel, indicated by our previous study, it is possible that these functional features reflect the internal environment of the molluscs (i.e. higher taurine and NaCl concentrations). Oyster taurine transporter mRNA expression was induced by not only hyper-osmotic stress, similar to other TAUT, but also hypo-osmotic stress. It is speculated that the expression in response to hypo-osmotic stress was induced by a substantial decrease in tissue taurine content following the decrease in the internal osmolality. 相似文献
979.
高压脉冲电场辅助提取鱼骨钙工艺优化 总被引:1,自引:1,他引:1
为了提高鱼骨钙的提取效果,利用高压脉冲电场从淡水鱼骨中辅助提取鱼骨钙制备高钙鱼骨水解液。单因素试验和二次通用旋转组合设计试验表明,脉冲数、电场强度、柠檬酸与苹果酸比对鱼骨钙的提取率影响显著;建立鱼骨钙提取率与各影响因子间关系的回归数学模型;确定了高压脉冲电场辅助提取鱼骨钙的最佳工艺参数为电场强度为25kV/cm、脉冲数为8个、柠檬酸与苹果酸的质量比为1:1g/g、酸料比为1:1g/g、水料比为12:1mL/g,此时处理4g鱼骨粉所得的鱼骨水解液中钙提取率达84.2%。与超声波辅助提取鱼骨钙对比试验表明,高压脉冲电场辅助提取鱼骨钙的得率较超声波辅助提取提高了17%,且其耗时短。该研究可为高压脉冲电场辅助提取鱼骨钙深入研究及其高钙鱼骨口服液的研制提供借鉴参考。 相似文献
980.