Effects of water stress at different development stages on yield and water productivity of winter and summer safflower (Carthamus tinctorius L.)

A field study was carried out to determine the effects of water stress imposed at different development stages on grain yield, seasonal evapotranspiration, crop-water relationships, yield response to water and water use efficiency of safflower (Carthamus tinctorius L.) for winter and summer sowing. The field trials were conducted on a loam Entisol soil in Thrace Region in Turkey, using Dincer, the most popular safflower variety in the research area. A randomised complete block design with three replications was used. Three known growth stages of the plant were considered and a total of 8 (including rainfed) irrigation treatments were applied. The effect of irrigation or water stress at any stage of development on grain yield per hectare and 1000 kernel weight, was evaluated. Results of this study showed that safflower was significantly affected by water shortage in the soil profile due to omitted irrigation during the sensitive vegetative stage. The highest yield was observed in the fully irrigated control and was higher for winter sowing than for summer sowing. Evapotranspiration calculated for non-stressed production was 728 and 673 mm for winter and summer sowing, respectively. Safflower grain yield of the fully irrigated treatments was 4.05 and 3.74 t ha⁻¹ for winter and summer season, respectively. The seasonal yield response factor was 0.97 and 0.81 for winter and summer sowing, respectively. The highest total water use efficiency was obtained in the treatment irrigated only at vegetative stage while the lowest value was observed when the crop was irrigated only at yield stage. As conclusions: (i) winter sowing is suggested; (ii) if deficit irrigation is to apply at only one or two stages, Y stage or Y and F stages should be omitted, respectively.     

Irrigation scheduling strategies for cotton to cope with water scarcity in the Fergana Valley, Central Asia

The Central Asian countries face high water scarcity due to aridity and desertification but excess water is often applied to the main irrigated crops. This over-irrigation contributes to aggravate water scarcity problems. Improved water saving irrigation is therefore required, mainly through appropriate irrigation scheduling. To provide for it, after being previously calibrated and validated for cotton in the Fergana region, the irrigation scheduling simulation model ISAREG was explored to simulate improved irrigation scheduling alternatives. Results show that using the present irrigation scheduling a large part of the applied water, averaging 20%, percolates out of the root zone. Several irrigation strategies were analyzed, including full irrigation and various levels of deficit irrigation. The analysis focused a three-year period when experiments for calibration and validation of the model were carried out, and a longer period of 33 years that provided for an analysis considering the probabilities of the demand for irrigation water. The first concerned a wet period while the second includes a variety of climatic demand conditions that provided for analyzing alternative schedules for average, high and very high climatic demand. Results have shown the importance of the groundwater contribution, mainly when deficit irrigation is applied. Analyzing several deficit irrigation strategies through the respective potential water saving, relative yield losses, water productivity and economic water productivity, it could be concluded that relative mild deficits may be adopted. Contrarily, the adoption of high water deficit that produce high water savings would lead to yield losses that may be economically not acceptable.     

cDNA cloning and complete primary structures of myosin heavy chains from brushtooth lizardfish Saurida undosquamis and wanieso lizardfish S. wanieso fast skeletal muscles

ABSTRACT:   The complete cDNA sequences encoding predominant types of myosin heavy chain (MYH) in the fast skeletal muscle were determined for brushtooth lizardfish Saurida undosquamis and wanieso lizardfish S. wanieso , which are used as materials for preparing high-quality surimi-based products. The cDNA consisted of 5973 and 5987 bp, respectively, and both encompassed an open reading frame encoding a polypeptide of 1936 amino acid residues. Brushtooth and wanieso lizardfish MYH showed the amino acid sequence identity of 92–93% to white croaker MYH, which was higher than that of 90% to walleye pollack MYH. The putative binding sites for ATP, actin, and regulatory and essential light chains in the subfragment-1 region of brushtooth lizardfish MYH exhibited a high identity with white croaker counterparts as well as the sequences of subfragment-2 and light meromyosin. In contrast, phylogenetic tree, constructed by the neighbor-joining method based on mitochondrial 16S rRNA gene, revealed that the two lizardfish species formed a cluster with walleye pollack, which was paraphyletic with white croaker. Therefore, a good reputation for lizardfish and white croaker to have a high thermal-gel forming ability seemed to be reflected by MYH rather than biological similarity as revealed by the mitochondrial 16S rRNA gene.     

鲫肠道上皮细胞原代培养方法的研究

探讨了健康鲫(Carassius auratus)幼鱼肠道上皮细胞的原代培养方法。结果显示,用含有抗生素、胶原蛋白酶Ⅰ、EDTA和胶原蛋白酶Ⅳ组成的D-Hanks液消化无菌分离的鲫肠道可以获得大量细胞团及绒毛隐窝;用含有抗生素、胎牛血清(FBS)、表皮生长因子(EGF)、胰岛素的DMEM培养液进行培养,并根据肠道上皮细胞与成纤维细胞贴壁时间的差异进一步纯化,连续培养12d后可以得到纯化的肠道上皮细胞。     

光唇鱼网箱养殖试验

网箱单养、混养光唇鱼的试验结果表明,在25m2网箱中,单养光唇鱼以200～220尾/m2的放养密度比较合适,单位面积产量可达12.7～12.9 kg/m2;瓯江彩鲤网箱中混养光唇鱼,在瓯江彩鲤保持180尾/m2的放养密度不变的情况下,混养20尾/m2的光唇鱼,其效果比单养瓯江彩鲤更好,单位面积产量可达103.2kg/m2.     

Energy and resource consumption of land-based Atlantic salmon smolt hatcheries in the Pacific Northwest (USA)

This paper evaluates the resource and energy requirements of six different types of land-based, hatchery production systems located in the U.S. Pacific Northwest: flow-through with a gravity water supply, flow-through with a pumped water supply, flow-through with pure oxygen, partial reuse system, partial reuse with heating, and a reuse system for the production of Atlantic salmon (Salmo salar) smolts. Key parameters used in the evaluation include direct energy, indirect energy, transportation energy, greenhouse gas emissions, and pollutant discharges.Power (electricity and natural gas) and feed energy accounted for the majority of the required energy for all the rearing option evaluated. The sum of the fixed capital and chemicals components accounted for less than 2–12% of the total energy budget for any rearing option. The energy efficiency (energy output/energy input) of the six options ranges from 0.97% for flow-through with pumped supply to 3.49% for the flow-through with gravity supply. The rearing options with the three highest energy efficiencies were flow-through with gravity supply (3.49%), partial reuse (2.75%), and reuse (2.64%).On a kg of smolt produced basis, the six rearing options showed a wide range in performance. The reuse system had the lowest water (2 m³ kg^− 1) and land (0.13 m² kg^− 1) requirements and the third lowest total energy requirement (288 MJ kg^− 1). The partial reuse system had the second lowest total power requirement (276 MJ kg^− 1), a low land requirement (0.21 m² kg^− 1), and moderate water requirements (33 m³ kg^− 1). The partial reuse with temperature control had the second highest total power requirement (657 MJ kg^− 1) and land and water requirements similar to the partial reuse system without temperature control. The flow-through system with pumped water supply had the highest water (289 m³ kg^− 1), land (2.19 m² kg^− 1), and energy requirements (786 MJ kg^− 1) of any of the rearing options. By comparison, the flow-through system with gravity water supply had the lowest energy requirement (218 MJ kg^− 1), a moderate land requirement (0.78 m² kg^− 1), and a high water requirement (214 m³ kg^− 1). The ranking of the six rearing options based capital and operating costs are likely to be quite different from those based on energy, water, and greenhouse gas emissions.     

基于滤食鱼类天然产力的安康库区生态负荷量测定

为厘清汉江水体鱼类集约养殖与生态负荷量的关系,测定安康库区滤食性鱼类天然鱼产力,测算Ⅱ类水质限定条件下的安康库区生态负荷量,并与以水体磷含量为标准的计算结果比较。结果表明,设定网箱深度3 m,单位水体生态负荷量为193.44 g/m³,总产量控制为10.47×10⁴ t。库区网养单产为100 kg/m³时,网箱养殖面积控制为1.93‰,网箱生态养殖面积与单位面积产量呈反比。     

春玉米叶片光合生理参数对土壤水分的阈值响应及其生产力分级

试验设正常灌水处理和干旱胁迫处理,讨论春玉米叶片的光合生理参数对土壤水分的阈值响应并进行生产力分级。结果表明:正常灌水处理的叶片光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)呈单峰曲线变化,胞间CO2浓度(Ci)和气孔限制值(Ls)对水分变化具有相反的响应变化。干旱胁迫处理下叶片的Pn、Tr在进行控水后明显下降,灌浆以前Pn下降主要是由气孔限制引起的。随着水分胁迫的加剧,光合结构受损,Pn下降,主要受非气孔因素限制。短期干旱胁迫会适当降低玉米的水分利用效率(WUE),但是下降程度不显著,WUE能达到中等水平。长期严重的水分胁迫后,WUE下降明显,与正常灌水处理相比差异极显著。以光合生理参数为指标对玉米土壤水分有效性及生产力进行分级与评价,确定当36.8%<土壤相对湿度(RWC)<42.7%时为低产低效水;42.7%相似文献   

Al2O3含量对烧结初始液流动行为的影响

在铁矿粉烧结过程中,初始液相流动行为是烧结矿固结效果的重要影响因素。采用微型烧结法,探讨了Al2O3含量对初始液相流动行为的影响,并通过对初始液相微观结构的解析,揭示了Al2O3含量对初始液相气孔分布和结构的影响规律。实验结果表明,初始液相的流动性指数随着Al2O3含量提高而降低。水淬试样的XRD实验结果结果证实,Al2O3含量的增加提高了复合铁酸钙的稳定性,降低了初始液相的流动能力。此外,初始液相流动性亦会对气孔性质产生影响。高Al2O3初始液相中气孔结构不规则程度提高,且小于50 μm气孔数目也随之增多。     

Comparisons of energy balance and evapotranspiration between flooded and aerobic rice fields in the Philippines

The seasonal and annual variability of sensible heat flux (H), latent heat flux (LE), evapotranspiration (ET), crop coefficient (K_c) and crop water productivity (WP_ET) were investigated under two different rice environments, flooded and aerobic soil conditions, using the eddy covariance (EC) technique during 2008-2009 cropping periods. Since we had only one EC system for monitoring two rice environments, we had to move the system from one location to the other every week. In total, we had to gap-fill an average of 50-60% of the missing weekly data as well as those values rejected by the quality control tests in each rice field in all four cropping seasons. Although the EC method provides a direct measurement of LE, which is the energy used for ET, we needed to correct the values of H and LE to close the energy balance using the Bowen ratio closure method before we used LE to estimate ET. On average, the energy balance closure before correction was 0.72 ± 0.06 and it increased to 0.99 ± 0.01 after correction. The G in both flooded and aerobic fields was very low. Likewise, the energy involved in miscellaneous processes such as photosynthesis, respiration and heat storage in the rice canopy was not taken into consideration.Average for four cropping seasons, flooded rice fields had 19% more LE than aerobic fields whereas aerobic rice fields had 45% more H than flooded fields. This resulted in a lower Bowen ratio in flooded fields (0.14 ± 0.03) than in aerobic fields (0.24 ± 0.01). For our study sites, evapotranspiration was primarily controlled by net radiation. The aerobic rice fields had lower growing season ET rates (3.81 ± 0.21 mm d⁻¹) than the flooded rice fields (4.29 ± 0.23 mm d⁻¹), most probably due to the absence of ponded water and lower leaf area index of aerobic rice. Likewise, the crop coefficient, K_c, of aerobic rice was significantly lower than that of flooded rice. For aerobic rice, K_c values were 0.95 ± 0.01 for the vegetative stage, 1.00 ± 0.01 for the reproductive stage, 0.97 ± 0.04 for the ripening stage and 0.88 ± 0.03 for the fallow period, whereas, for flooded rice, K_c values were 1.04 ± 0.04 for the vegetative stage, 1.11 ± 0.05 for the reproductive stage, 1.04 ± 0.05 for the ripening stage and 0.93 ± 0.06 for the fallow period. The average annual ET was 1301 mm for aerobic rice and 1440 mm for flooded rice. This corresponds to about 11% lower total evapotranspiration in aerobic fields than in flooded fields. However, the crop water productivity (WP_ET) of aerobic rice (0.42 ± 0.03 g grain kg⁻¹ water) was significantly lower than that of flooded rice (1.26 ± 0.26 g grain kg⁻¹ water) because the grain yields of aerobic rice were very low since they were subjected to water stress.The results of this investigation showed significant differences in energy balance and evapotranspiration between flooded and aerobic rice ecosystems. Aerobic rice is one of the promising water-saving technologies being developed to lower the water requirements of the rice crop to address the issues of water scarcity. This information should be taken into consideration in evaluating alternative water-saving technologies for environmentally sustainable rice production systems.