Comparison of drip and sprinkler irrigation strategies on sunflower seed and oil yield and quality under Mediterranean climatic conditions

This study compares the effects of different irrigation regimes on seed yield and oil yield quality and water productivity of sprinkler and drip irrigated sunflower (Helianthus annus L.) on silty-clay-loam soils in 2006 and 2007 in the Mediterranean region of Turkey. In sprinkler irrigation a line-source system was used in order to create gradually varying irrigation levels. Irrigation regimes consisted of full irrigation (I₁) and three deficit irrigation treatments (I₂, I₃ and I₄), and rain-fed treatment (I₅). In the drip system, irrigation regimes included full irrigation (FI-100), three deficit irrigation treatments (DI-25, DI-50, DI-75), partial root zone drying (PRD-50) and rain-fed treatment (RF). Irrigations were scheduled at weekly intervals both in sprinkler and drip irrigation, based on soil water depletion within a 0.90 m root zone in FI-100 and I₁ plots. Irrigation treatments influenced significantly (P < 0.01) sunflower seed and oil yields, and oil quality both with sprinkler and drip systems. Seed yields decreased with increasing water stress levels under drip and sprinkler irrigation in both experimental years. Seed yield response to irrigation varied considerably due to differences in soil water contents and spring rainfall distribution in the experimental years. Although PRD-50 received about 36% less irrigation water as compared to FI-100, sunflower yield was reduced by an average of 15%. PRD-50 produced greater seed and oil yields than DI-50 in the drip irrigation system. Yield reduction was mainly due to less number of seeds per head and lower seed mass. Soil water deficits significantly reduced crop evapotranspiration (ET), which mainly depends on irrigation amounts. Significant linear relationships (R² = 0.96) between ET and oil yield (Y) were obtained in each season. The seed yield response factors (ky_seed) were 1.24 and 0.86 for the sprinkler and 1.19 and 1.06 for the drip system in 2006 and 2007, respectively. The oil yield response factor (ky_oil) for sunflower was found to be 1.08 and 1.49 for both growing seasons for the sprinkler and 1.36 and 1.25 for the drip systems, respectively. Oil content decreased with decreasing irrigation amount. Consistently greater values of oil content were obtained from the full irrigation treatment plots. The saturated (palmitic and stearic acid) and unsaturated (oleic and linoleic acid) fatty acid contents were significantly affected by water stress. Water stress caused an increase in oleic acid with a decrease in linoleic acid contents. The palmitic and stearic acid concentrations decreased under drought conditions. Water productivity (WP) values were significantly affected by irrigation amounts and ranged from 0.40 to 0.71 kg m⁻³ in 2006, and from 0.69 to 0.91 kg m⁻³ in 2007. The PRD-50 treatment resulted in the greatest WP (1.0 kg m⁻³) and irrigation water productivity (IWP) (1.4 kg m⁻³) in both growing seasons. The results revealed that under water scarcity situation, PRD-50 in drip and I₂ in sprinkler system provide acceptable irrigation strategies to increase sunflower yield and quality.     

测定原油比热容技术问题的探讨

采用精密的量热仪测定含虹原油的比热容也会产生较大的偏差，基信要原因在于测试过程中量热容器内存在着两个相变过程，邓气液之间的相变液相析出石蜡结晶的相变，以及随着温度下降试样内传热性能变坏。     

大豆不同结荚部位籽粒蛋白质、脂肪含量分析

对4个不同类型大豆品种的上、中上、中、中下、下、分枝六部分籽粒进行品质分析,各部分蛋白质和脂肪含量差异显著、极显著。蛋白质含量从上至下由高变低(40.010％、38.890％、38.110％、36.428％、35.888％);无限结荚习性大豆脂肪含量(19.983％、20.873％、21.242％、21.797％、21.908％)与蛋白质相反;亚有限结荚大豆脂肪含量上至中下由低变高(21.411％、21.993％、22.113％、22.538％),下部(22.151％)低于中下部;分枝上籽粒蛋白质、脂肪含量与中上部差异不显著;全株品质平均值(38.024％、21.760％)接近于中部值。     

微胚乳超高油玉米籽粒胚乳消减及油分积累的规律

[目的]研究微胚乳超高油玉米籽粒胚乳消减和油分积累规律。[方法]以高油玉米115为对照,研究2种微胚乳超高油玉米籽粒的胚、胚乳、种皮及相应油分的积累规律。[结果]微胚乳超高油玉米在籽粒发育过程中胚乳干重在发育的第27 d达最大,第37 d消减基本结束;胚的重量一直增加,种子成熟时和胚乳的重量相当;整粒干重第32 d达最大。3个玉米品种授粉后的种皮干重一直增加,第32 d基本稳定,整粒油分37 d前一直增加,之后趋于稳定。微胚乳超高油玉米胚乳的油分在17~27 d增加较慢,27~37 d增加迅速,37 d到成熟期下降,比高油115的高很多;胚的油分在17~27 d增加,27 d到成熟期略下降。高油玉米115胚和胚乳的重量一直增加,胚乳的油分一直很低,胚的油分在17~27 d增加。[结论]该研究为微胚乳超高油玉米的籽粒胚乳消减机理研究提供了参考。     

白玫瑰挥发油化学成分的研究

本研究采用GC/MS/DS联用技术,分析了白玫瑰花挥发油的化学成分。从分离的的44化合物中,鉴定了41个组分,占挥发油总含量的97.64%。白玫瑰挥发油的主要成分是β—笨乙醇,含量高达86.53%,其次是丁香酚(4.75%)和香叶醇(2.45%)。     

日粮添加豆油和胡麻油对肉牛瘤胃发酵及主要微生物数量的影响

 【目的】评价日粮添加植物油对瘤胃发酵和瘤胃微生物区系的影响。【方法】采用3×3拉丁方设计，用3头装有永久性瘤胃瘘管的杂交肉牛研究不添加油脂（对照组）、添加4％豆油（豆油组）或4％胡麻油（胡麻油组）对瘤胃pH值、NH3-N浓度、VFA以及瘤胃细菌和原虫的影响。3组日粮精粗比均为35﹕65，每期试验为21d，共3期。【结果】添加油脂对瘤胃内pH值没有影响(P＞0.05)；对照组和胡麻油组瘤胃NH3-N浓度显著高于豆油组(P＜0.05)；与对照组相比，豆油组和胡麻油组显著降低了瘤胃乙酸、丙酸、丁酸、总挥发性酸浓度以及总细菌、蛋白分解菌、纤维分解菌及原虫的数量(P＜0.05)，但对乙酸与丙酸比例以及淀粉分解菌数量两个指标组间无显著差异(P＞0.05)。对照组、豆油组和胡麻油组纤维分解菌和原虫的数量依次分别为6.79×108、5.71×108、5.92×108；10.67×104、7.11×104、9.56×104 CFU•ml-1；两个加油组显著降低了瘤胃纤维分解菌和原虫数(P＜0.05)。【结论】日粮添加4％豆油和胡麻油对瘤胃发酵及主要微生物都有一定的抑制效应，但二者抑制效应大小无显著差异。     

Methane fluxes from three ecosystems in tropical peatland of Sarawak, Malaysia

Methane fluxes were measured monthly over a year from tropical peatland of Sarawak, Malaysia using a closed-chamber technique. The CH₄ fluxes in forest ecosystem ranged from −4.53 to 8.40 μg C m⁻² h⁻¹, in the oil palm ecosystem from −32.78 to 4.17 μg C m⁻² h⁻¹ and in the sago ecosystem from −7.44 to 102.06 μg C m⁻² h⁻¹. A regression tree approach showed that CH₄ fluxes in each ecosystem were related to different underlying environmental factors. They were relative humidity for forest and water table for both sago and oil palm ecosystems. On an annual basis, both forest and sago were CH₄ source with an emission of 18.34 mg C m⁻² yr⁻¹ for forest and 180 mg C m⁻² yr⁻¹ for sago. Only oil palm ecosystem was a CH₄ sink with an uptake rate of −15.14 mg C m⁻² yr⁻¹. These results suggest that different dominant underlying environmental factors among the studied ecosystems affected the exchange of CH₄ between tropical peatland and the atmosphere.     

Impacts of chronic marine oil pollution and the murre hunt in Newfoundland on thick-billed murre Uria lomvia populations in the eastern Canadian Arctic

We developed a deterministic and stochastic age-based matrix projection population model to assess and quantify the impact of mortality caused by chronic oil pollution and legal hunting on thick-billed murre Uria lomvia populations breeding and wintering in eastern Canada. We calculate the potential population growth rate in the absence of anthropogenic mortality sources using a modeling technique that translates absolute number of birds killed from anthropogenic mortality to potential survival rates in the absence of these anthropogenic impacts. The intrinsic growth rate of the deterministic matrix based on vital rates from Coats Island (λ_d=1.0102), as well as the stochastic growth rate (λ_s=1.0098, 95% C.I. 0.9969-1.0226), matched observed population trends. Hunting mortality reduced population growth rate by 0.020 (0.012-0.039), oiling mortality reduced population growth rate by 0.025 (0.012-0.039). Combined these sources reduced the population growth rate by 0.047 (0.033-0.610). Although thick-billed murre populations are stable or slowly growing in eastern Canada, anthropogenic sources of mortality are reducing the ability of the population to grow, and increase vulnerability in these populations to changes in their environment and other pulse perturbations. Our modeling technique could be used to assess specific anthropogenic impacts on populations where a vital rates and numbers killed are known, but no long-term trend information is available.     

Combined microbial community level and single species biosensor responses to monitor recovery of oil polluted soil

Understanding the effects of oil contamination on the composition and function of soil microbiota entails investigation of the effects of a mixture of hydrocarbons at the community level in a complex environmental matrix. One approach to this difficult problem is to ally a community-level fingerprinting approach with bioassays that have a physiological or functional implication. Two contrasting refined oils (paraffin and motor oil) were used to contaminate soil microcosms, and a simulated bioremediation treatment with nutrient-addition was applied. The indigenous microorganisms were monitored over 103 d using complementary community-level techniques (carbon source physiological profiling using Biolog^® microplates, and phospholipid fatty acid (PLFA) profiling). Changes in the toxicity of the applied oils were monitored using luminescent bacterial bioassays, including Vibrio fischeri and a hydrocarbon-degrading Pseudomonas putida strain. Distinct shifts in microbial community structure and C source utilization profiles were observed as a result of oil contamination. There was some evidence that bioremediated soils were returning to control values by the end of the experiment. This was supported by the bioassay results which showed an initial increase in toxicity as a result of the oil addition which had then decreased by the conclusion of the experiment. The two oils exhibited markedly different toxicity towards the bioassay organisms, with species-specific differences in response. This oil-specific difference was also found in the PLFA profiles which showed the two oil types selected different microbial communities.     

油用向日葵新葵19号恢复系654R的选育及利用

[目的]研究油用向日葵恢复系的选育方法。[方法]在现有技术中向日葵恢复系的选择过程比较漫长且结果不明确的情况下,为了改变从杂种一代F1以后连续自交的作法,在早代就开始进行测定其配合力,有目的的选择,方向比较明确,提高选择效率,创造新的优异资源。[结果]选育出油用向日葵新葵19号恢复系654R,该恢复系植株性状好、抗病性好、抗逆性强、配合力高、杂种优势强。[结论]该研究提供了一种油用向日葵恢复系新的选育方法,并对654R进行利用。