透气型砂栽培研究进展与前景分析

透气型砂栽培（Sandponics）是生态环保、低成本、低技术的无土栽培技术,符合当前中国国情和世界无土栽培发展趋势。阐明透气型砂栽培系统的组成结构,提出透气型砂栽培基质的粒径、含盐量、含泥量和酸碱度等理化指标,探讨砂栽培营养液元素种类和要求,分析透气型砂栽培生产可持续性理论基础,建立透气型砂栽培技术标准,为透气型砂栽培的进一步研究和生产实践提供参考。分析透气型砂栽培蔬菜产品的含糖量、亚硝酸盐含量、重金属含量等营养品质。总结透气型砂栽培的特点和所具备的生态意义、社会意义,分析透气型砂栽培在都市农业和南海岛屿蔬菜生产实践中的应用前景。     

狼毒根原料特点及其中柱制备糠醛研究

瑞香狼毒是我国北方草原上典型的多年生草本毒植物,资源化利用是新的治理思想和方式。以青海湖南岸的狼毒为研究对象,对其根部原料特征、化学成分和中柱部分制备糠醛进行了测定分析。结果表明:狼毒根皮层厚度与其最大直径呈直线关系;含水量为4.5%时,狼毒根中柱密度(0.72 g/cm~3)略高于皮层密度(0.69 g/cm~3);狼毒根中柱与皮层的化学成分有较大差异。由于狼毒根中柱部分聚戊糖含量较高,适合作为制备糠醛的原料,本研究中糠醛的得率为8.2%,与目前工业常用的原料蔗渣相仿。研究结果可为狼毒资源化提供参考依据。     

A new sustainable formulated feed based on discards from food industries for rearing the sea urchin Paracentrotus lividus (Lmk)

During a 18‐week experiment in a sea‐based system, Paracentrotus lividus was fed with two formulations of a new sustainable feed whose main ingredients were food farming discards, mostly outermost lettuce leaves, in different percentage. Egg white was added as protein source and binder, and a little amount of commercial fish feed was added as lipid source. At the end of the experiment, a high survival rate (>80%) and an increase in test diameter (22%), total weight (130%), gonad weight (240%) and gonad index expressed as size‐adjusted gonad weight (288%) were recorded. Gonads achieved a good colour and high levels of essential and polyunsaturated fatty acids, hence representing a commercially valuable product. Comparing the two feed formulations, the one with the lower lettuce content (57% vs. 67%) led to the best product quality, in terms of gonad features (gonad index and colour) and content of essential fatty acids. In order to move towards a higher sustainability of the aquaculture sector, this study proposes a low‐cost feed, produced with cheap and sustainable ingredients such as food farming discards.     

A Study of Lipid Bioaccessibility in Canned Sardine (Sardina pilchardus) and Chub Mackerel (Scomber japonicus)

The lipid composition and bioaccessibility in canned sardine (Sardina pilchardus) and chub mackerel (Scomber japonicus) were studied. Triacylglycerols were absent from the bioaccessible fraction in both products and each FA had a different bioaccessibility level. While total fat bioaccessibility was in the 60–64% range, the bioaccessibility of ω6 PUFA and DHA was <55%. Bioaccessibility depended on canned fish product species: fat, EPA, DHA, and ω3 PUFA bioaccessibility levels seemed to be higher in canned sardine than in canned mackerel. Daily consumption of 278 g of canned mackerel or 47 g of canned sardine would ensure the recommended daily intake of EPA+ DHA.     

Putting the pieces together: Recent growth,nutritional condition,and mortality of Engraulis anchoita larvae in the Southwest Atlantic

Dynamics of clupeiform fish populations such as anchovy are frequently impacted by environmental variations which can affect the success of the species recruitment. Herein, we have analyzed recent otolith growth rate, RNA/DNA nutritional condition index (sRD), and mortality rate of argentine anchovy larvae Engraulis anchoita from three different nursery areas in the Southwest Atlantic. We have evaluated the relationship between the environmental variables (abundance of copepod nauplii, temperature, chlorophyll‐a concentration, and abundance of E. anchoita larvae) and larval endogenous variables (size, weight, age, and otolith radius) to sRD and recent growth rate. Fast larval growth rates were observed toward the northern sector of the studied area, characterized by higher temperature. High values of sRD were associated with higher nauplii abundance in the proximity of coastal fronts. The larvae with the lowest growths and lowest minimum values of nutritional condition coincided with the area where there was less abundance of nauplii and higher larval mortality. Larval size and nauplii abundance were positive explanatory factors for both recent growth rate and sRD index. Temperature had a positive effect on recent growth rate and a negative effect on sRD index. This condition index was poorly explained in terms of model fit in comparison with the growth model. The results herein provided could be significant to better understand the recruitment of the species, as to determining favorable areas for the growth and survival of anchovy larvae.     

Effect of dietary oxidized oil and vitamin E on growth performance,lipid peroxidation and fatty acid profile of Labeo rohita fingerlings

A 3 × 3 factorial experiment was conducted on Labeo rohita fingerlings to evaluate the effect of dietary oxidized oil and vitamin E. Nine experimental diets were made, based on three degrees of oil oxidation (fresh oil, low oil oxidation and high oil oxidation), and each level of oxidation was further supplemented with three levels of vitamin E (0, 100 and 1,000 mg/kg). Weight gain% and specific growth rate (SGR) of fish fed fresh fish oil and low oil oxidation level were significantly higher than highly oxidized oil. Moreover, vitamin E supplemented fish also showed better growth performance. Oil oxidation caused a significant reduction in the concentrations of α‐tocopherol and increase in TBARS level and antioxidant enzyme activities in fish liver and muscles. However, increasing the dietary vitamin E abrogated these effects. Dietary vitamin E supplementation improved the fatty acid, more specifically polyunsaturated fatty acids profile of oxidized oil fed fish. In conclusion, dietary oxidized fish oil increased the oxidative stress condition of fish but supplementation of high dose of vitamin E prevented lipid oxidation, improved growth performance and fatty acid profile of L. rohita.     

Feed intake,growth, feed utilization,body composition and waste output of juvenile hybrid bream at different feeding frequencies

An eight‐week feeding trial was conducted to evaluate the feed intake, growth, feed utilization, body composition and waste output of juvenile hybrid bream at different feeding frequencies (0.5, 1, 2, 3 or 4 meals/day). Fish (initial body weight of 10.6 ± 0.8 g) were fed to satiation at each feeding. The test diet contained 336 g/kg crude protein and 79 g/kg crude lipid. The weight gain significantly increased with increase in feeding frequency from 0.5 to 3 meals/day (p < 0.05) and afterwards did not change with feeding frequency from 3 to 4 meals/day (p > 0.05). The feed intake increased with increase in feeding frequency (p < 0.05). Fish fed at 3 meals/day exhibited the lowest feed conversion ratio and waste output of nitrogen and phosphorus, however, the highest nitrogen retention efficiency (p < 0.05). No significant differences were found in the phosphorus retention efficiency, the body composition of crude protein, ash and phosphorus among all the feeding frequencies (p > 0.05). The body lipid content increased, whereas the content of moisture decreased, with the increase in feeding frequency (p < 0.05). The present study reveals that the optimum feeding frequency is 3 meals/day for hybrid bream.     

灯盏花成分专用型种源评价与鉴定

收集和鉴定了云南省和贵州省共46份灯盏花种质资源,筛选出适合生产不同药品的成分专用型种源,为专用型品种选育提供参考。利用HPLC测定了灯盏花种源10种活性成分含量,相关分析阐明各成分含量间的相关性,聚类分析对种质资源进行分类。结果表明：16份灯盏花种源灯盏乙素（scutellarin, SE）含量在2.5%以上,是培育灯盏花素专用型品种的优良材料,其中4份种源同时含有高含量（>1.0%）的双咖啡酰奎宁酸酯（dicaffeoylquinic acids, diCQAs）,是培育灯盏细辛专用型品种的优良材料;同时,筛选出8份总黄酮（total flavonoids, TFs）含量高于3.5%的种源,适合选育总黄酮专用品种。相关性分析表明,SE含量与diCQAs和TFs含量均显著正相关,是灯盏花品质育种的标志性成分。聚类分析将灯盏花种源分为三大类,除1个种源的SE含量和diCQAs含量接近（第Ⅲ类）外,其他种源SE均占总活性成分的60%以上,其中第Ⅰ类为高TFs型种源,TFs占到总活性成分的80%以上,diCQAs占总成分的15%以下;第Ⅱ类为高diCQAs型种源,diCQAs占总成分的16.9%~28.9%,TFs占到总活性成分的80%以下。该结果表明灯盏花种源活性成分组成存在多种类型,为专用型品种选育提供了可能,灯盏乙素含量可以作为专用型种源筛选的首要指标。     

Hydrological and water cycle processes of inland river basins in the arid region of Northwest China

The increasing shortage in water resources is a key factor affecting sustainable socio-economic development in the arid region of Northwest China(ARNC). Water shortages also affect the stability of the region's oasis ecosystem. This paper summarizes the hydrological processes and water cycle of inland river basins in the ARNC, focusing on the following aspects: the spatial-temporal features of water resources(including air water vapor resources, runoff, and glacial meltwater) and their driving forces; the characteristics of streamflow composition in the inland river basins; the characteristics and main controlling factors of baseflow in the inland rivers; and anticipated future changes in hydrological processes and water resources. The results indicate that:(1) although the runoff in most inland rivers in the ARNC showed a significant increasing trend, both the glaciated area and glacial ice reserves have been reduced in the mountains;(2) snow melt and glacier melt are extremely important hydrological processes in the ARNC, especially in the Kunlun and Tianshan mountains;(3) baseflow in the inland rivers of the ARNC is the result of climate change and human activities, with the main driving factors being the reduction in forest area and the over-exploitation and utilization of groundwater in the river basins; and(4) the contradictions among water resources, ecology and economy will further increase in the future. The findings of this study might also help strengthen the ecological, economic and social sustainable development in the study region.