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1.
Robert A. Moreau David B. Johnston Kevin B. Hicks 《Journal of the American Oil Chemists' Society》2007,84(11):1039-1044
All commercial corn oil is obtained by pressing corn germ and/or extracting the germ with hexane. In the current study, six
types of corn oil were prepared by extracting corn germ, corn fiber and ground corn, each with hexane or with ethanol. The
levels of lutein, zeaxanthin and other carotenoids were quantitatively analyzed in the six corn oils. The levels of lutein + zeaxanthin
in the oil ranged from 2.3 μg/g for hexane-extracted corn germ oil to 220.9 μg/g for ethanol-extracted ground corn oil. These
results indicate that a diet that includes 30 g (~2 tbsp) per day of the unrefined corn oil obtained by extracting ground
corn with ethanol would provide ~6 mg of lutein + zeaxanthin, the daily dosage that is currently considered to be necessary
to slow the progression of age-related macular degeneration.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
2.
硼在玉米中的分布特征及化学形态的研究 总被引:1,自引:0,他引:1
对施硼肥和不施硼肥的土壤上种植的玉米中硼的分布及化学形态进行了研究 ,结果表明 ,靠近根部的玉米叶子中含硼最多 ,中部和上部叶子中含硼量依次递减 ,玉米种子中的含硼量低于叶子中的含硼量。通过研究不同溶剂对玉米叶子和种子中硼的浸提能力 ,探明了以 10 %醋酸浸提下来的硼最多 ,其次是用 0 .0 1mol/LEDTA浸提下来的硼 ,用水浸提下来的硼的含量最少。 相似文献
3.
Germplasm with shorter duration than that of the currently grown varieties is being generated to maximize productivity of irrigated rice. However, short-duration varieties often produce yields lower than the medium- and long-duration varieties. Experiments were conducted during the 1980–82 dry and wet seasons to increase productivity through the use of very early-maturing rices and the improved management of nitrogen (N) fertilizers.Results over three years showed that IR58 and IR9729-67-3 (growth duration 100 ± 5 days) yield as well as or higher than IR36 although earlier maturing. They generally had a higher productivity (kg ha–1 day–1) than IR36 (110 ± 5 days).Three years' data suggest that the improved timing of broadcast applications of urea in split doses increased grain yield comparable with the basal incorporation of slow-release sulfur-coated urea (SCU) or deep point-placement of urea supergranules (USG).Results on elite breeding lines showed that the early-maturing IR9729-67-3 produced higher protein yield ha–1 than longer duration varieties such as IR8 and IR42 in the dry season. Furthermore, contrary to earlier results, single basal incorporation of slow-release SCU increased the protein yield of rice by 53 kg ha–1 and deep point-placement of USG by 43 kg ha–1 over split application of prilled urea. 相似文献
4.
5.
采用孕穗期干旱处理前喷施有效微生物群(EM)研究干旱对玉米叶片膜脂过氧化和抗性酶及产量的影响。结果表明:EM能明显降低MDA含量,提高SOD和CAT活性,增强玉米的抗旱性并提高产量。 相似文献
6.
LAMP实时浊度法是采用环介导等温扩增(Loop Mediated Isothermal Amplification,LAMP)技术通过实时浊度仪实时检测反应过程中所产生的白色沉淀,从而实现对扩增全过程的监控,弥补了显色法只能观看反应终点的缺陷,使引物筛选和反应体系的优化有数据可依。本研究以转基因玉米MON810为研究对象,针对外源基因苏云金芽孢杆菌杀虫毒蛋白CryIA(b)与内源基因边界序列设计6条特异性引物,通过实时浊度法在63 ℃的恒温条件下完成检测,对检测的灵敏度、特异性、稳定性进行了评价。建立了转基因玉米MON810的LAMP实时浊度检测方法,该方法最低检出限为0.5%,与LAMP显色法和实时荧光PCR法进行结果比对,符合率为100%,经评价具有特异性高、稳定性强、准确简便等优点,非常适合转基因玉米MON810的快速检测,有较好的应用价值。 相似文献
7.
8.
Jens M. Vesterager Niels E. Nielsen Henning Høgh-Jensen 《Nutrient Cycling in Agroecosystems》2008,80(1):61-73
Symbiotic N2-fixation, N uptake efficiency, biomass- and crop production of cowpea and maize as affected by P source, sole- and intercropped,
and introduction of break crops were studied on a farmer’s fields in semi-arid Tanzania. Cowpea fixed around 60% of its N
from the atmosphere amounting to 70 kg N ha−1 under sole and 36 kg N ha−1 under intercropping as estimated by the 15N isotope dilution method around peak biomass production. The amount of N2-fixed was 30–40% higher when P was applied as either TSP or MRP whereas cowpea yield were unaffected. Intercropped maize
with 19,000 plant ha−1 accumulated the same amount of N as 38,000 sole cropped maize plants although intercropping reduced the dry matter accumulation
by 25%. The N uptake efficiency of the applied 15N labelled fertiliser was 26%, which equal a total pool of early available plant N of 158 kg N ha−1. Under the N deficient conditions, P application did not increase the grain yield of maize. The LER indicate that sole cropping
required 18% more area than intercropping in order to produce the same grain yield, and 35% more land when LER was based on
N uptakes. Introduction of break crops in the maize systems, more than doubled accumulation of dry matter and N in the grain
compared to continuous maize cropping. During maturation sole crop cowpea shedded leaves containing 41 kg N ha−1. The current findings underline the importance of crop diversity in Sub Saharan Africa agriculture and emphasise the need
for including all residues, including shedded leaves, in nutrient balance studies. 相似文献
9.
The efficacy and persistence of two commercially available enhanced diatomaceous earth (DE) products (Dryacide® and Protect-It®) against four common tropical storage pests (Prostephanus truncatus, Sitophilus zeamais, Callosobruchus maculatus and Acanthoscelides obtectus) were studied when admixed with typical host commodities at different application rates and relative humidities. Persistence of the enhanced DE treatments was considered after 3 and 6 months storage by assessment of both adult mortality and F1 progeny emergence. Both DEs usually increased parental mortality and reduced progeny emergence of all four insect species in comparison with the untreated control at both 50% and 60% r.h., and at all storage periods. However, efficacy was inversely related to duration of storage and over time the host commodity also became less suitable for insect development. Each insect species differed in its susceptibility to the DE treatments, highlighting the need for field application rates to be based upon the entire spectrum of pest species likely to be present during storage. 相似文献
10.
Nitrous oxide emission from upland crops and crop-soil systems in northeastern China 总被引:2,自引:0,他引:2
X. Chen M.L. Cabrera L. Zhang J. Wu Y. Shi W.T. Yu S.M. Shen 《Nutrient Cycling in Agroecosystems》2002,62(3):241-247
Although it is known that crops can directly emit N2O, their contribution to the total N2O emission from crop-soil systems under field conditions is not well understood. This study was conducted to study the contribution
of crops to total N2O emission from soybean-soil and maize-soil systems in northeastern China. The effects of N fertilization on N2O emission and NO
3
−
-N concentration in plants were also studied. The emission from crop-soil systems was measured with the closed chamber method,
whereas the direct emission from crops was measured with the soil surface-sealed method. The addition of fertilizer N significantly
increased the NO
3
−
-N concentration in crops and enhanced the N2O emission from crop-soil systems and from crops alone. The amount of N2O emitted directly from soybean plants accounted for 6 to 11% of the total soybean-soil emission. Similarly, the amount of
N2O emitted directly from maize plants accounted for 8.5 to 16% of the total maize-soil emission. The proportion of the applied
N lost through direct N2O emission from plants ranged from 0.19 to 0.34%, whereas the proportion of the applied N lost through N2O emission from the crop-soil system ranged from 1.1 to1.9%. These results suggest that the use of chambers that do not include
plants may lead to an underestimation of the total N2O emission from crop-soil systems.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献