Genetic and environmental variability in starch,fatty acids and mineral nutrients composition in cowpea (Vigna unguiculata (L) Walp)

Fifteen cowpea cultivars grown in three locations (Kano (12°00′N 8°31′E), Mokwa (9°17′N 5°04′E) and Ago-Iwoye (6°58′N 4°00′)) between 1993 and 1994 were analysed for genotype, environmental and genotype×environment variability for starch (g kg⁻¹), fatty acids (% of total oil) and mineral nutrients (g kg⁻¹) composition. There were significant environmental as well as genetic effects on these nutritional qualities. The environmental effect accounted largely for the variability observed in starch (60%), palmitic acid (80%), arachidic acid (100%), potassium (100%), phosphorus (81%) and manganese (86%), while the genotypic effect accounted largely for the variability observed in linoleic acid (50%), linolenic acid (50%) and copper (68%) contents. Correlation coefficient (pooled data) from the three locations indicated that starch was positively correlated to palmitic acid (r = 0·21, 0·01< P < 0·05), potassium (r = 0·80, P < 0·001) and phosphorus (r = 0·65, P < 0·001), but negatively correlated to oleic (r = −0·23, 0·01< P < 0·05), linoleic (r = −0·67, P < 0·001) and linolenic acid (r = −0·74, P < 0·001) contents. Starch showed a strong positive correlation with magnesium content (r = 0·75) and a strong negative correlation with copper (r = −0·73) and iron (r = −0·62) at the genetic level. This research established the degree of variability for these characters in cowpea. © 1998 Society of Chemical Industry.     

Human urine - Chemical composition and fertilizer use efficiency

Stored human urine had pH values of 8.9 and was composed of eight main ionic species (> 0.1 meq L^–1), the cations Na, K, NH₄, Ca and the anions, Cl, SO₄, PO₄ and HCO₃. Nitrogen was mainly (> 90%) present as ammoniacal N, with ammonium bicarbonate being the dominant compound. Urea and urate decomposed during storage. Heavy metal concentrations in urine samples were low compared with other organic fertilizers, but copper, mercury, nickel and zinc were 10–500 times higher in urine than in precipitation and surface waters. In a pot experiment with¹⁵N labelled human urine, higher gaseous losses and lower crop uptake (barley) of urine N than of labelled ammonium nitrate were found. Phosphorus present in urine was utilized at a higher rate than soluble phosphate, showing that urine P is at least as available to crops as soluble P fertilizers.     

明日叶中营养成分及生物活性物质的检测分析

目的:对明日叶中的营养成分和生物活性物质查尔酮的含量进行检测分析。方法:采用国标法对明日叶中的营养成分含量进行检测分析,并用紫外可见分光光度法测定明日叶中查尔酮的含量。结果:明日叶中含有蛋白质4.71%、还原糖1.65%、粗纤维3.64%、脂肪0.19%、水分84.79%、灰分0.72%,VB10.02mg/100g、VB20.71mg/100g、VC45.90mg/100g、叶酸0.30mg/100g、VB123.20μg/100g,钾110.00mg/100g、钙140.21mg/100g、镁1.50mg/100g、铁14.03mg/100g、锗20.67μg/100g;测得的18种氨基酸含量为2.85g/100g,其中8种人体必需氨基酸含量为1.11g/100g,占18种氨基酸总量的38.9%;生物活性物质查尔酮含量为0.75%。结论:明日叶中含有多种有益于人体健康的营养成分,其中蛋白质含量比常见蔬菜高,其氨基酸模式较为理想,且含有丰富的粗纤维、VC、VB2和叶酸,维生素在叶中的含量尤其丰富,还有植物少有的VB12和有机锗及罕见的生物活性物质查尔酮,具有较高的研究价值和保健功效,应用前景广阔。      

大型水库热分层的水质响应特征与成因分析

为研究大型水库热分层期间水质的响应特征及成因,于2018年4月-2018年12月对大黑汀水库坝前水体的水温及溶解氧等理化指标进行了连续性垂向监测,在此基础上分析了大黑汀水库季节性热分层变化规律以及各水质指标的响应特征.结果表明:(1)大黑汀水库水体呈典型的单循环混合模式,热分层期间,溶解氧在垂向分布同样表现出季节性变化...     

日粮中添加乳化剂对肉鸡脂肪代谢的影响

研究在猪油日粮中添加500g/t乳化对内鸡生产性能、养分表观利用率及胴体品质的影响.结果表明:添加乳化剂提高了肉鸡前期、后期及全期的平均日增重(P>0.05),降低了料重比(P>0.05),提高了肉鸡前期粗蛋白质(P<0.01)、能量(P<0.05)的表现利用率;乳化剂能降低42日龄肉鸡肌间脂肪宽度(P<0.05)和皮下脂肪厚度(P<0.01),提高胸肌和腿肌重(P<0.05);乳化剂也使21日龄肉鸡腹脂重明显降低(P<0.05).     

三峡水库支流水华机理及其调控技术研究进展

三峡水库自2003年蓄水以来,水库干支流水环境状况及支流水华问题已成为广泛关注的问题,国内外不少科研单位及学者对此进行了大量的研究。本文在介绍三峡水库蓄水以来水库水质状态及支流水华情势的基础上,系统总结了关于三峡水库干支流水动力特征及其环境效应、水华机理及其调控措施的研究发现,并提出了有待进一步研究的内容。主要研究发现包括:(1)三峡水库蓄水后支流库湾普遍存在分层异重流现象,产生的原因是干支流温度差及泥沙浓度差引起的水体密度差,其中水体温度差是主要因素;(2)在分层异重流的驱动下,支流库湾水体呈现\"双混斜\"及\"半U\"型特殊水体分层模式,支流库湾营养盐也主要来自于水库干流倒灌;(3)流速变缓只是支流暴发水华的表观原因,分层异重流驱动下的混合层(Zm)与临界层(ZCr)的关系变化才是决定水华生消的关键;(4)水库水位升降可通过影响分层异重流的形态、改变支流水体分层状态进而调控支流水华的生消过程,基于此提出了防控支流水华的\"潮汐式\"生态调度方法。如何将上述新发现上升为具有三峡水库特色的系统理论与方法,实现支流水华的精准预测预报,开展能够协调水库传统效益和防控支流水华等生态效益的三峡及上游梯级水库群联合多目标优化调度实践,应是今后进一步努力的方向。     

保水缓释肥在药用植物板蓝根上的试验研究

为了解决干旱作物农业地区养分不足和水资源短缺的问题,将保水剂与化学肥料按比例配合制得了既能吸水保水抗旱保墒,又具有缓释肥料功效的保水缓释肥。采用药用植物板蓝根为试验对象进行盆栽试验,对其保水效应及板蓝根生长状况进行观察分析,得出了保水缓释肥可以提高土壤的水分利用率、合理释放土壤有效养分、促生长作用明显的结论。     

Consumption,intake patterns,and exposure

Despite the wide public and scientific interest in antioxidant nutrients and their roles in disease prevention, limited data are available to assess population consumption, individuals’ intake patterns, and trends in exposure. This article reviews data on levels of these nutrients in the food supply, intake patterns from food and supplement use derived from national surveys, and trends in exposure. The food supply and intake data indicate that levels of vitamins E and C and the carotenoids in the diet have increased since the 1970s, but the increases are not consistent among all age groups. Dietary supplements make a major contribution to intakes of vitamins E and C. Nutrient and nonnutrient antioxidants added to the food supply do not contribute appreciably to antioxidant exposure. Groups at high risk of poor dietary intakes of antioxidant nutrients are the poor, tobacco users, nonsupplement users, and the elderly, especially those living alone.     

Relationships between minerals in Australian brown rice

Ninety samples of brown rice cv Amaroo, which has occupied over 50% of the area sown to rice in southern Australia in the last two seasons, were collected from the rice growing regions of southern Australia at the end of the 1991–1992 season. The samples were analysed for total nitrogen using the Kjeldahl technique, and for P, K, S, Mg, Ca, Na, Al, Cu, Fe, Mn, Mo and Zn using inductively coupled plasma emission spectroscopy. The analysis of concentrations of elements show that Mn concentrations in Australian rice were higher and Ca concentrations lower than typical values reported for brown rice grown in other countries. For all other elements the concentrations had a similar range to those reported for overseas rice. Highly significant correlations were found between the major nutrients P, K and Mg, and also N and S. The Mg to K ratio ranged from 1·3 to 1·6 which indicates that, if Japanese criteria are used, the taste/stickiness quality within this cultivar of Australian rice could vary from undesirable to highly desirable.