温度对双眉藻生长的影响

为研究培养温度对底栖硅藻双眉藻(Amphora sp. HN08)比生长速率和脂肪、蛋白及多糖等细胞主要成分的影响,将双眉藻培养于25、30、35和38℃四 个温度条件下,6 d后测定细胞的比生长速率、总脂、可溶性蛋白和总糖的含量。结果表明：培养温度对双眉藻的生长和细胞主要成分含量有显著影响。双眉藻在38℃条件下生长最快,但总脂含量仅为细胞干重的12.9%;30和35℃培养条件下细胞油脂积累量最多,分别达到细胞干重的44.8%和44.1%;培养于20℃条件下藻细胞的可溶性蛋白和总糖含量显著高于其他处理,但细胞的比生长速率显著低于其他温度条件。     

激素IAA和ABA对小球藻（Chlorella sp.）生长和油脂积累的影响

从北部湾地区淡水水域分离得到一株高含油量小球藻藻株,将其培养在高碳培养基TAP上,研究不同浓度IAA和ABA对其生物量和油脂积累的影响。结果表明：添加10μmol/L IAA对藻株的生长有明显的促进作用,其最大生物量比对照组增加了58.24%,但其油脂含量却比对照组降低了34.71%;而当增加IAA浓度为20μmol/L时,对藻株的生长表现出明显的抑制作用,其最大生物量比对照组减少了53.60%,但其油脂含量与对照组相比显著增加,增加了95.46%。添加2μmol/L ABA对藻株生长的抑制作用极其明显,其生物量比对照组降低了57.52%,但其油脂含量与对照组相比显著提高,提高了121.49%。同时添加IAA（20μmol/L）和ABA（2μmol/L）的实验藻种的蛋白质和总糖的含量较对照组有所降低,此外也使叶绿素含量和光合效率降低。       

三角褐指藻 LPAAT基因在酵母中表达对脂肪酸的影响

从三角褐指藻（Phaeodactylum tricornutum）中克隆到1 632bp的溶血磷脂酸酰基转移酶(LPAAT)全长cDNA,其中包含的开放阅读框被命名为PtLPAAT。在毕赤酵母中异源表达PtLPAAT基因,诱导培养45h时随机选取的3个酵母转化子总脂肪酸含量分别提高了2.68%、11.14%、31.28%;诱导培养72h时同样的转化子总脂肪酸含量分别提高11.59%、18.72%、46.63%。用薄层层析法分离48h后的酵母菌体的甘油三酯,并用气相色谱法测定其脂肪酸,结果显示：与非转基因对照菌株相比,其油酸提高了0.9倍、亚油酸提高了5倍。用荧光定量PCR检测发现PtLPAAT基因的表达量随三角褐指藻油脂不断积累逐渐升高。表明在酵母中表达PtLPAAT基因不仅能够明显地提高其脂肪酸含量,而且还能选择性结合不饱和脂肪酸到甘油三酯中。     

植物生长调节剂2,4-D和GA3对微茫藻18A8(Micractinium sp.)生长和油脂积累的影响

实验室分离到1株含油量高并且生长迅速的微茫藻18A8(Micractinium sp.)藻株,将其培养在高碳培养基TAP上,研究了不同浓度的植物激素2,4-二氯苯氧乙酸(2,4-D)和赤霉素(GA3)对其生物量和油脂积累的影响。结果表明：分别添加2,4-D(2 μmol/L)和GA3(1 μmol/L)对藻株的生长有明显的促进作用,其最大生物量比对照组分别增加75.26%和47.41%,但其油脂含量与对照组相比却有所降低,分别降低了23.49%和29.89%;而当增加2,4-D和GA3浓度为10和5 μmol/L时,对藻株的生长表现出明显的抑制作用,其最大生物量比对照组减少了72.83%和60.70%,但其油脂含量与对照组相比显著增加,分别增加149.45%和95.75%。同时,分别添加2,4-D(10 μmol/L)和GA3(5 μmol/L)的实验藻种的蛋白质和总糖含量较对照组有所降低,此外叶绿素含量和光合效率也降低。     

叶面喷施硒肥对黑大豆生长及品质的影响

以临黑2号、临黑3号为试验材料,研究在大田生态模式下,花荚期叶面喷施不同浓度硒肥对夏播黑大豆产量构成因子和品质影响。结果表明:两个黑大豆品种叶面喷施不同浓度的绿维康有机富硒肥产量均有增加,但各处理间差异不显著;产量构成因子各处理间差异不显著,籽粒硒含量比对照显著增加。临黑2号在硒肥喷施浓度为0.1%时,产量最高,籽粒蛋白质含量和蛋脂总含量最高,籽粒硒含量随硒肥浓度增加而增加;临黑3号在硒肥喷施浓度为0.2%时,产量最高,籽粒蛋白质含量和蛋脂总含量最高,硒肥喷施浓度为0.3%时,籽粒硒含量达到最大。     

施用石灰与生物炭对酸性土壤花生氮素吸收及产量的影响

为明确石灰与生物炭对酸化土壤改良及花生氮营养的作用效果，通过田间小区试验，研究了石灰、生物炭单施与配施对酸化土壤性质、花生氮素吸收利用及生长发育的影响。结果表明，与CK相比，单施石灰显著提高了土壤pH值、有机质、碱解氮和交换性钙含量，花生植株氮吸收量和收获指数显著增加13.1%和4.6%，花生生物量和产量显著提高11.7%和16.1%；单施生物炭显著增加了土壤pH值、有机质、碱解氮含量和土壤碳氮比，但对花生氮吸收量、生物量和产量无显著影响；表明酸性土壤明显抑制了花生生长，单施石灰促进花生生长及氮高效利用效果优于生物炭。石灰与生物炭配施后，土壤pH值、有机质、碱解氮、交换性钙含量及碳氮比更协调，花生植株氮吸收量、氮利用率、生物量和产量均得到进一步提高。所有处理中，4500 kg/hm²生物炭配施450 kg/hm²石灰处理的花生植株氮吸收量、氮收获指数、氮利用率、生物量及产量最高，分别比CK增加30.7%、8.7%、5.7%、27.6%和35.8%。因此，4500 kg/hm²石灰和450 kg/hm²生物炭配施是酸性土壤改良、氮素高效及花生高产栽培的有效手段。     

营养元素限制对微芒藻Y-002油脂积累的影响

研究1株由海南本地分离的微芒藻(Micractinium pusillum)Y-002,在氮、硫、磷、铁营养限制条件下藻细胞光合效率以及油脂积累的变化情况。结果表明,在氮、硫缺乏条件下,细胞生长减缓、光合效率下降、细胞油脂积累增加。细胞组分分析显示,在氮、硫缺乏条件下,总糖和总蛋白含量下降;油脂含量增加。NaAc能促进细胞光合效率,提高细胞生长速率和油脂积累。在SE缺氮培养时,外加15 mmol/L NaAc比未添加NaAc的培养生物量提高51%,油脂含量提高10倍。     

ALA对刺葡萄愈伤组织生长及主要抗氧化物质积累的影响

以刺葡萄红色愈伤组织为材料,研究不同浓度ALA处理对刺葡萄愈伤组织生物量及主要抗氧化物质（黄酮类化合物、原花青素和花色苷）积累量的影响,明确ALA与刺葡萄愈伤组织生长、主要抗氧化活性物质合成的相关性。结果表明：中低浓度（0.05~1.0 mg/L）ALA可促进刺葡萄愈伤组织生长,显著增加刺葡萄愈伤组织的生物量;同时,中低浓度ALA能显著增加刺葡萄细胞中黄酮类化合物、原花青素和花色苷的含量;高浓度（2.0~5.0 mg/L）ALA会抑制刺葡萄愈伤组织生长,并最终导致褐变死亡;刺葡萄愈伤组织主要抗氧化物质积累也存在显著的培养阶段差异,在ALA最适浓度0.05 mg/L时,刺葡萄细胞中黄酮类化合物含量最高可达272.48 μg/g（培养45 d）、花色苷含量最高达107.24 μg/g（培养35 d）、原花青素含量最高达1630.16 μg/g（培养45 d）。由结果可知,ALA可以定向调控刺葡萄愈伤组织细胞中主要抗氧化物质的生物合成。     

三角褐指藻岩藻黄素合成途径及其关键基因对高光照的响应

以三角褐指藻为材料,以岩藻黄素的合成途径中主要的六个酶:八氢番茄红素合成酶、八氢番茄红素脱氢酶、ζ-胡萝卜素脱氢酶、胡萝卜素异构酶、番茄红素β-环化酶和玉米黄素环氧酶为研究对象,研究高光照胁迫对三角褐指藻岩藻黄素合成代谢途径中关键基因表达量以及岩藻黄素含量的变化规律。以光照强度为500μE/(m2·s),分别照射处理三角褐指藻3h、6h、12h,采用HPLC对岩藻黄素含量进行定量分析。随着光照时间的延长,岩藻黄素含量呈现先上升后下降的趋势;高光照6h样品中岩藻黄素含量为1.85mg·g-1DW(dry cell weight),比高光照0h对照组中岩藻黄素含量增加了2.16倍。qRT-PCR分析结果表明玉米黄素环氧酶基因zep1和八氢番茄红素合成酶基因pys转录本在高光照胁迫6h时丰度最高,与对照组相比提高了近2倍,基因表达量的变化表现出与岩藻黄素含量变化相一致的趋势。高光照处理3h后,胡萝卜素异构酶基因crtiso3、八氢番茄红素脱氢酶基因pds、ζ-胡萝卜素脱氢酶基因zds的表达水平相比于对照组明显降低,表现出应对高光照胁迫的快速响应;番茄红素β-环化酶基因lcyb、胡萝卜素异构酶基因crtiso1的表达水平则在高光照处理12h后明显提高;与zep1和pys相比,lcyb和crtiso1基因的表达对高光照胁迫处理的响应时间要滞后至少6h。本研究揭示了高光照胁迫处理下三角褐指藻中岩藻黄素含量及其合成途径中关键基因的表达模式,表明zep1和pys基因表达水平与岩藻黄素合成量之间存在明显的线性关系。     

添加甘蔗糖蜜对湖泊红球藻及其虾青素合成的影响

虾青素(Astaxanthin)是类胡萝卜素的含氧衍生物,具有较强的抗氧化、清除自由基等功能;湖泊红球藻(Haematococcus lacustris)是天然虾青素的最好来源之一。为了明确用甘蔗糖蜜或葡萄糖为培养基碳源对湖泊红球藻生长及其合成虾青素的影响,在BG11培养基中分别添加浓度为0.5、1、1.5 g/L的糖蜜或葡萄糖,在正常光照强度40μmol/(m2·s)添加0.5 g/L糖蜜或葡萄糖的试验组的藻细胞在培养至45 d时,藻细胞生长达到最大,分别是对照组的1.21倍或1.29倍。在高光照150μmol/(m2·s)培养第30d时,总糖0.5 g/L的糖蜜培养基培养下藻细胞的虾青素含量显著高于对照组和相同总糖浓度的葡萄糖组,分别是对照组的1.86倍、葡萄糖组的1.33倍;藻细胞干重也显著高于对照组和相同浓度的葡萄糖组,分别是对照组的1.81倍、葡萄糖组的1.80倍。结果表明,添加低浓度糖蜜或葡萄糖均可以提高湖泊红球藻的生物量及虾青素含量,低浓度葡萄糖有利于保持藻细胞在高光胁迫下的活力,而低浓度糖蜜培养基能显著促进藻细胞虾青素的积累。     

Combined Effects of Nitrogen Concentration and Seasonal Changes on the Production of Lipids in Nannochloropsis oculata

Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L⁻¹ day⁻¹) compared to N-sufficiency (0.11 g L⁻¹ day⁻¹). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material.     

Year-Round Cultivation of Tetraselmis sp. for Essential Lipid Production in a Semi-Open Raceway System

There is increasing demand for essential fatty acids (EFAs) from non-fish sources such as microalgae, which are considered a renewable and sustainable biomass. The open raceway system (ORS) is an affordable system for microalgae biomass cultivation for industrial applications. However, seasonal variations in weather can affect biomass productivity and the quality of microalgal biomass. The aim of this study was to determine the feasibility of year-round Tetraselmis sp. cultivation in a semi-ORS in Korea for biomass and bioactive lipid production. To maximize biomass productivity of Tetraselmis sp., f medium was selected because it resulted in a significantly higher biomass productivity (1.64 ± 0.03 g/L) and lower omega-6/omega-3 ratio (0.52/1) under laboratory conditions than f/2 medium (0.70/1). Then, we used climatic data-based building information modeling technology to construct a pilot plant of six semi-ORSs for controlling culture conditions, each with a culture volume of 40,000 L. Over 1 year, there were no significant variations in monthly biomass productivity, fatty acid composition, or the omega-6/omega-3 ratio; however, the lipid content correlated significantly with photosynthetic photon flux density. During year-round cultivation from November 2014 to October 2017, areal productivity was gradually increased by increasing medium salinity and injecting CO₂ gas into the culture medium. Productivity peaked at 44.01 g/m²/d in October 2017. Throughout the trials, there were no significant differences in average lipid content, which was 14.88 ± 1.26%, 14.73 ± 2.44%, 12.81 ± 2.82%, and 13.63 ± 3.42% in 2014, 2015, 2016, and 2017, respectively. Our results demonstrated that high biomass productivity and constant lipid content can be sustainably maintained under Korean climate conditions.     

Natural silicates mixed with organic fertilizers enhance corn adaptation to salt stress and improve physical characteristics of sandy soil

Soil salinity is one of the major environmental constraints to crop productivity worldwide. Therefore, the development of cost-effective and environment-friendly techniques allowing increased crop productivity and soil fertility under saline conditions is rather urgent today. The objective of this investigation was to study the effects of mixtures containing natural silicates (analcite, bergmeal, and potassium silicate) and organic fertilizers (sapropel, peat) in corn (Zea mays L.). We specifically evaluated tolerance of corn to salinity stress and certain characteristics of saline soil (viz., redox potential, conductivity, and phytotoxicity) using a factorial pot experiment, modeling NaCl salinity levels of 0, 50, 100, 150, and 200 mM under greenhouse conditions. Growth, water balance, photosynthesis, catalase activity, and accumulation of nonenzymatic antioxidants (flavonoids and anthocyanins) were measured and evaluated. Salinity stress reduced shoot and root biomass by 8–49%, photosynthetic pigment content in leaves by 15–30%, deteriorated water balance, and activated nonspecific adaptive reactions (i.e., accumulation of enzymatic and nonenzymatic antioxidants) in the corn seedlings. All the tested silicon-containing mixtures stimulated corn seedling resistance to salt stress and reduced soil phytotoxicity. This was reflected in the stimulation of growth of the corn seedlings (accumulation of shoot biomass, and formation and growth of lateral roots). The content of photosynthetic pigments, flavonoids, anthocyanins, catalase activity increased 1.3–2 times compared with plants that received NaCl only. The difference between treatments and control was most pronounced at moderate levels of salinity (100–150 mM). The mixture containing silicon minerals and sapropel (9:1 proportion) showed the highest protective effect against salinity stress.     

不同光照条件下杜鹃红山茶幼苗的生长效应及抗氧化生理响应

以两年生杜鹃红山茶(Camelliaazalea)扦插苗为材料,研究遮光率分别为0、30%、50%、80%条件下其生长发育和生理指标的变化,以分析光照强度对杜鹃红山茶生长发育和相关生理指标的影响,为合理栽培及提高品系抗性提供参考。结果表明:随遮光率的增加,杜鹃红山茶的苗高、地径、冠幅、分枝数、成活率、根部干质量、茎部干质量、叶片干质量、总干质量均有一定程度的增加,且均在50%遮光条件下处于最高水平。随着遮光强度的增加,叶片丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均表现出先降低后上升的趋势,且均在50%遮光条件下处于最低水平;叶片中游离氨基酸含量表现出逐渐下降的趋势。因此,适度的遮光处理有助于杜鹃红山茶幼苗的生长,50%遮光条件下杜鹃红山茶幼苗栽植效果最佳。     

Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity

References

Genetic improvement in water uptake ability and/or water use efficiency (WUE) of rice cultivars is one option to enhance productivity under water-limited conditions. We examined the genotypic variation in biomass production among 70 rice cultivars (69 cultivars of NIAS global rice core collection and Azucena) under different soil moisture conditions, and to identify whether water uptake ability or WUE is responsible for the variation, if any. Two-week-old seedlings were transplanted into pots and grown for three weeks in an environmentally-regulated growth chamber under three soil moisture regimes: flooded (?0.02 MPa soil water potential) and two unflooded (?0.10 and ?0.52 MPa) conditions. Substantial genotypic variations in total dry weight (TDW) were observed under all three regimes. Among all the cultivars tested, TDW was significantly correlated with water uptake ability, but not with WUE. However, several cultivars exhibited comparably higher WUE while showing superior biomass production under the ?0.52 MPa regime. The amount of water uptake was significantly correlated with root dry weight among cultivars regardless of moisture regimes, while substantial genotypic difference in the amount of water uptake per unit root dry weight was observed. These results indicate that a marked genotypic difference exists in biomass production at the early vegetative growth under water-deficient conditions, and that this difference appears to be ascribed primarily to greater water uptake capacity, and additionally to higher WUE in drought-tolerant cultivars.     

Biomass, organic carbon and mineral matter contents of abaca (Musa textilis Nee) at different stages of growth

This study was conducted to measure the biomass, organic carbon and mineral matter contents of abaca at different stages of growth as baseline information for material cycling of the plant. These were attained through destructive sampling of the identified sample plants. Different parameters such as moisture content, dry matter, organic carbon and mineral matter contents were determined. Regression and correlation analyses were also conducted to find out possible relationship between growth parameters and plant biomass.Biomass contents ranged from 11 to 21% regardless of the growth stages of abaca. Based on the weight of partitioned components, biomass, organic carbon and mineral matter contents (g/plant) of all tissues increased as the growth of abaca plant progressed. Pseudostem tissue showed the highest percent moisture content but it also showed the highest biomass (dry weight per plant) during the vegetative and flagleaf stages of growth. The pseudostem biomass accounted nearly two-thirds of the above-ground biomass at harvesting stage in the production system. Cumulative effect could be disadvantageous and would most likely result to nutrient imbalance in the system due to crop removal and nutrient mining. A strong relationship was found between biomass and pseudostem length (r = 0.997).     

Narrow row planting increases yield and suppresses weeds in common bean (Phaseolus vulgaris L.) in a semi-arid agro-ecology of Nyagatare,Rwanda

Narrow row planting has potential to increase crop growth and yield by increasing radiation interception (RI) and minimizing intra-specific competition in the crop. It reduces weed growth and competitiveness, making resources that are normally taken up by weeds available for crop uptake. The objective of this study was to assess the effect of row spacing on weed biomass, bean growth and yield in a semi arid agro-ecology at Nyagatare, Rwanda. The study was set up as a randomized complete block design in October–December 2009 and repeated in 2011. Planting patterns at a constant bean population density of 111 000 plants ha⁻¹ random planting (normal practice), narrow row planting (30 cm × 30 cm), medium row planting (45 cm × 20 cm) and wide row planting (60 cm × 15 cm) were treatments tested in this study. The narrow row square planting pattern significantly (P < 0.01) out-yielded the wide and random planting patterns by 22–31% in the wet 2009 season and by 27–70% in the dry 2011 season. Bean plant dry weight (P < 0.01) and number of pods per plant (P < 0.01) was highest in the narrow row and lowest in the random planting pattern in the dry 2011 season. Bean plant dry weight was not significantly affected (P > 0.05) in the wet 2009 season but number of pods plant⁻¹ (P < 0.001) was highest in the narrow row and lowest in the random planting pattern. Weed biomass was significantly lower (P < 0.05) in the narrow row and the random than in the medium and wide row planting patterns at 3, 6 and 9 weeks after emergence in 2009, but the random planting had the highest weed biomass in 2011. The results suggest that the effects narrow row planting in alleviating the negative impact of inter- and intra-specific competition were more strongly expressed in the dry 2011 season than the wet 2009 season when water was probably not a limiting factor to crop growth and yield. The results also indicate that narrow and equidistant planting has potential to increase bean yield by 30%–70%, when compared to random planting (normal practice) while at the same time suppressing weed growth and is recommended for smallholder farmers in Rwanda and other semi-arid areas in sub-Saharan Africa.     

Characterisation of oat (Avena sativa L.) oil bodies and intrinsically associated E-vitamers

Transmission electron microscopy of sections of oat (Avena sativa L.) grain suggested that the highest concentrations oil bodies were in the aleurone and germ rather than the starchy endosperm. Oil bodies recovered from homogenized tissues by centrifugation and washed in (9 M) urea were significantly (P<0.05) enriched in lipid (93.3±1.4% dry wt) and low in protein (1.4±0.2%) compared with unwashed (40.2±1.9% lipid; 23.0±1.8% protein), water-washed (78.6±1.2% lipid; 7.8±0.5% protein), and salt-washed (1 M NaCl) oil bodies (89.9±0.4% lipid; 5.1±0.4% protein). Washing significantly reduced (P<0.05) the total phenolic content of the oil bodies but significantly increased concentrations of E-vitamers, on a dry weight basis, suggesting an intrinsic association between the E-vitamers and oat oil bodies. The profile of E-vitamers in the oil bodies reflected that in oat grain with α-tocotrienol accounting for ca. 66% of the total E-vitamers. These E-vitamers may provide oxidative stability to the membrane and/or oil of oat oil bodies     

The effect of water salinity on potatoes (Solanum tuberosum L.): Physiological indices and yielding capacity

Summary The response of several potato cultivars to salinity levels of 20.5, 34.2 and 51.3 mM NaCl was investigated. Salinity tended to lower the water and the osmotic potentials of leaves and tubers while increasing the content of total soluble solids and of proline; it also increased the content of dry matter in the tubers and reduced tuber yields. Susceptibility to salinity was described by the relative loss of tuber dry weight. ‘Blanka’ tolerated the lowest NaCl level (20.5 mM) and exhibited moderate tolerance to higher levels when exposed to salinity stress for 37 days.before harvest, but was susceptible when exposed to the higher levels for 63 days. Cv. Alpha showed moderate tolerance, loosing up to 15% of tuber dry weight when exposed to salinity levels of 20.5 and 34.2 mM NaCl. Mechnisms involved in the adaptation of potatoes to salinity stress are discussed. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 2206-E, 1987 series.