江苏3种大戟属野生植物总脂含量及脂肪酸组分分析

利用索氏抽提法提取并采用气相色谱法测定了大戟属能源植物续随子的江苏野生近缘种甘肃大戟、乳浆大戟和钩腺大戟不同组织总脂含量、种子中总脂的脂肪酸组成及GC含量.结果表明,其茎、叶、种皮、种子及块根中,种子的总脂含量最高,在3个物种中分别为37.29%、24.50%和24.85%,其次是叶和茎,种皮含量最小;甘肃大戟种子的总脂含量高达37.29%,具有较好的开发潜力;3种植物种子总脂的脂肪酸组成中二十碳以下(多数为十八碳)的脂肪酸总和均为90%以上,甘肃大戟种子的总脂中二十碳以下的脂肪酸的总和甚至超过99%,在碳链长度上与理想的生物柴油组分接近,但3种大戟种子的总脂中亚麻酸比例在53%以上,生产出的生物柴油稳定性较差.     

高产能源植物绿玉树品系间差异研究Ⅰ品系间生长速度差异

为揭示绿玉树品系间生长速度的差异,选择快速生长的品系,对海南岛绿玉树天涯海角等7个品系扦插后的单株鲜重增长率和单株分枝数增长率进行了研究.结果表明:扦插后86 d,绿玉树的单株鲜重增长率品系间存在显著或极显著差异,其中以海大4号的单株鲜重增长率最高、达403.2%,且极显著高于天涯海角、显著高于海大2号;品系间的单株分枝数增长率也存在显著或极显著差异,其中以海大3号的单株分枝数增长率(970.3%)最高,其次为海大2号(856.3%),两者均极显著高于天涯海角、显著高于昆明,而单株分枝数增长率居第3位的是海大5号(739.2%)也极显著高于天涯海角.     

Effect of applying calcium chloride and three milk supplements to poinsettia ‘Prestige Red’

Some poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) cultivars are susceptible to bract calcium (Ca) deficiency in developing bracts. In this study, we evaluated the efficacy of foliar uptake of Ca from milk-based products plus calcium chloride (CaCl₂) as a potential Ca source. Weekly foliar applications of 237 mL L^?1 whole milk, 80 mL L^?1 powdered milk, 30 mL L^?1 condensed milk, 0.94 g L^?1 CaCl₂, or distilled water (used as a control) were applied to runoff of ‘Prestige Red’ for four weeks. The four largest bracts with petioles on three different inflorescences and three leaves with petioles below the transitional leaf per inflorescence were collected per pot. None of the treatments affected bract or leaf Ca concentration. Powdered milk treatments resulted in a higher concentration of zinc (Zn) in bracts and aluminum (Al) in bracts and leaves. White residue remained on the bracts and leaves after treatment with powdered milk, which would reduce marketability.     

不同提取方法对续随子种子中不饱和脂肪酸得率的影响

[目的]寻求续随子种子不饱和脂肪酸的最佳提取方法和条件。[方法]分别采用挥发油测定法、索氏提取法和超声提取法从续随子种子中提取续随子油,对3种方法的提取效果进行了比较,并对提取产品甲酯化和续随子种子油甲酯化后的脂肪酸产物进行GC-MS分析。[结果]3种提取方法中,挥发油测定法的最高产率为0.45%,索氏提取法45.46%,超声提取法47.20%,它们的不饱和脂肪酸的最高含量分别为9.09%、85.28%、85.72%,表明超声提取法的提取效果优于其他2种方法。GC-MS分析表明,续随子种子中含有丰富的不饱和脂肪酸类,达到总脂肪酸90%以上,具有较好的开发前景。[结论]超声提取法是最佳的提取方法,正交试验表明其最佳条件为:提取次数3次,料液比1∶10,提取时间为20 min。     

Control of one invasive plant species allows exotic grasses to become dominant in northern Great Plains grasslands

Decline of leafy spurge (Euphorbia esula) in the northern Great Plains of the US is generally viewed as a success story for biological control, but quality of the vegetation that survived the infestation is key to recovery of ecosystem function. In addition, effects of other invasive species, notably cool-season exotic grasses, must be taken into account. Objectives of this study were (1) to evaluate direction and significance of changes in biomass of native and exotic grasses, forbs, and leafy spurge and in plant species composition following control of leafy spurge by flea beetles and (2) to evaluate the relative effects of leafy spurge and exotic grasses on biomass of native grasses, biomass of forbs, and richness of native species. We monitored species composition (1998-2003 and 2008) and biomass (2000, 2002, 2003 and 2008) of these groups on spurge-infested and noninfested permanent plots at three sites with unbroken prairie sod in North Dakota, USA. We found little evidence, in terms of species richness or biomass of native grasses or forbs, that leafy spurge was being replaced by desirable native species, although desirable as well as weedy and exotic species were characteristic of 2008 vegetation at all three sites. Structural equation models revealed that leafy spurge had temporally intermittent negative effects on forb biomass and species richness, but no effects on native grasses. In contrast, exotic grass had consistently strong, negative effects on native grass biomass, as well as stronger negative effects than leafy spurge on native species richness. Although substantial native plant diversity remains at these sites, exotic grasses pose an important threat to these crucial building blocks of native prairie ecosystems.     

Effect of aqueous Euphorbia hirta leaf extract on gastrointestinal motility

The aqueous leaf extract of Euphorbia hirta decreased the gastrointestinal motility in normal rats and decreased the effect of castor oil-induced diarrhoea in mice.     

温度、光照和水分对飞扬草种子萌发和幼苗生长的影响

为明确热带常见杂草飞扬草(Euphorbia hirta)的种子萌发特性,本研究运用培养皿滤纸法和盆栽法,分别研究温度、光照和水分条件对飞扬草种子萌发和幼苗生长的影响。结果表明,飞扬草种子在20~40℃范围内均可萌发,其中30℃为种子萌发的最适温度(萌发率和萌发指数均最大),25℃时幼苗生长最好(根长/苗长为1.031)。恒温条件(25℃)下,光照8~24h时的种子萌发率无显著差异(平均值94.07%)、光/暗0h/24h时萌发率降至52%(P0.05),萌发指数随光照时间缩短先增大后降低,光/暗16h/8h时最大(93.93),0h/24h最低(30.59);有光照时幼苗的根长均显著大于苗长,无光照时苗长显著大于根长(P0.05)。变温条件(光/暗,35℃/25℃)下,光照时长对飞扬草种子萌发率和幼苗苗长无显著影响(P0.05),随光照时长缩短萌发指数和幼苗根长均显著减低(P0.05)。综合各指标,12~16h光照为飞扬草种子萌发和幼苗生长的最佳光照条件。25℃、光/暗12h/12h条件下,飞扬草在土壤最大持水量60%时的种子出苗率达39%、幼苗根长苗长比为1.10∶1。     

乳浆大戟提取物的杀虫抑菌活性研究

生物农药开发前景广阔,乳浆大戟作为一种中草药,分布广、资源丰富,可利用其自身的毒性开发生物农药。以75%乙醇加热萃取法提取乳浆大戟中的活性成分,进行了杀虫抑菌生物活性试验,为乳浆大戟开发为新型生物农药提供科学依据。试验结果表明：提取物对果蝇及桃蚜具有良好的毒杀活性,提取物对果蝇的半致死量LC50为75.51 mg/mL,果蝇死亡率与提取物浓度呈正相关,对桃蚜毒性的半致死量LC50为9.35 mg/mL,当提取物浓度为50 mg/mL时对桃蚜的校正死亡率为85.59%;提取物对大肠杆菌、金黄色葡萄球菌以及枯草芽孢杆菌均有一定的抑菌作用,其中对枯草芽孢杆菌抑制作用较强,最大抑菌圈直径为1.53 cm;25 mg/mL的提取物对玉米大斑病菌落扩展有明显抑制作用,抑菌率45.28%,对盆栽玉米苗大斑病的防治效果为36.63%。     

Chemical management of weeds in corn hybrids

Corn stands out among the cultivars because of its high importance in food, animal feed and raw materials for energy production. The quantity and quality of the harvested grain can be reduced, mainly due to inadequate weed management. Nowadays, weed control is accomplished with the use of herbicides as pre‐emergence and postemergence, applied alone or in a tank mix. This study aimed to evaluate the efficiency of the control of weeds and phytotoxicity of the herbicides that were applied in tank mix or isolated in the corn hybrids, Formula TL® and SYN 7B28 . Two experiments were conducted: in the 2012/2013 season (Formula TL®) and 2013/2014 season (SYN 7B28). There was a low initial phytotoxicity of all the tested herbicides in the initial evaluation; however, from 14 days after treatment, it was minimal. The weed control of Ipomoea indivisa, Urochloa plantaginea and Euphorbia heterophylla in both experiments was better, in general, when using the tank mixtures of atrazine + simazine + tembotrione and atrazine + simazine + mesotrione, respectively. The application of atrazine + simazine + tembotrione in the SYN 7B28 hybrids provided, with the exception of the thousand‐grain weight, the best expression of grain yield components, combining a low phytotoxicity and best control of the weeds. The Formula TL® hybrid presented the highest mass of a thousand grains and yield with the application of nicosulfuron + tembotrione. The yield average difference of the herbicide treatments and the unweeded control showed an increase of 27.66 and 34.59% in the grain yield of the corn hybrids, Formula TL® and SYN 7B28, respectively.     

五指毛桃黄酮和香豆素类成分研究

对五指毛桃的化学成分进行了研究.分离得到11个化合物,根据理化性质和波谱数据,分别鉴定为补骨脂素(Ⅰ)、伞形花内酯(Ⅱ)、 5,3',4'-三羟基-3,7-二甲氧基黄酮(Ⅲ)、 5,7,2',4'-四羟基黄酮(Ⅳ)、 5-羟基-3,7,4'-三甲氧基黄酮(Ⅴ)、山柰酚(Ⅵ)、紫云英苷(Ⅶ)、金合欢素 7-O-β-D-吡喃葡萄糖苷(Ⅷ)、木犀草素7-O-β-D-吡喃葡萄糖苷(Ⅸ)、柚皮素(Ⅹ)及胡萝卜苷(Ⅺ).经检索,化合物Ⅱ～Ⅹ为首次从该植物中分离得到,化合物Ⅲ、Ⅳ、Ⅴ、Ⅷ、Ⅸ为首次从该属植物中分离得到.