博落回杀灭鱼类指环虫和病原菌活性成分的研究

采用常压硅胶柱层析和RP-HPLC制备并结合杀虫、抑菌活性追踪的方法,从博落回中分离获得了杀灭金鱼指环虫和抑制鱼类病原菌的活性成分,通过TLC、UV、m.p.、IR、MS、1H NMR和13C NMR鉴定其为血根碱.杀灭指环虫试验结果表明:血根碱对指环虫有较强杀灭活性,在质量浓度为0.6 mg?L-1时的杀虫率达到100%.血根碱对6株水产致病菌的活性试验结果表明:对嗜水气单胞菌的活性最高,MIC和MBC分别为12.5和25μg·mL-1;对哈维弧菌、鳗弧菌、杀鲑气单胞菌史氏亚种的活性最弱,其MIC和MBC均分别为50和100μg·mL-1.血根碱杀灭鱼类指环虫活性较高,对6株水产病原菌都有明显抑制作用.     

22种植物提取物及其6种化合物对鱼类指环虫的杀灭研究

将感染有指环虫的金鱼投放在加有一定浓度的植物提取物或化合物的水体中,控制一定的水体条件,显微镜下定期观察鱼鳃上的指环虫数量,统计杀虫率。结果表明:22种植物中蛇床提取物的杀灭指环虫效果最好,其最高杀灭率为100%;其次是两面针、木通、吴茱萸、牛心朴子,最高杀虫率均为80%;夹竹桃、徐长卿的最高杀虫率均为70%;草果、苦木、北乌头、滨蒿、蒺藜、白芷、山柰、榧的最高杀虫率在48 h内均在20%~50%;在测试浓度范围内,生姜、辣椒、仙茅、大风子、泽漆、相思子和雷丸没有明显杀虫活性。6种植物化合物作用48 h时川楝素的杀灭指环虫活性最高,最高杀灭率为100%;其次是鬼臼毒素、烟碱和槟榔碱,杀虫率在30%~50%;青蒿素和苦参碱在鱼中毒浓度下对指环虫仍然没有杀灭效果。根据以上结果,蛇床、两面针、木通、吴茱萸、牛心朴子、夹竹桃、徐长卿等植物和化合物川楝素对鱼类指环虫具有较好的杀灭作用。     

海芒果叶挥发油化学成分及杀虫活性研究

采用水蒸气蒸馏法提取,运用气相色谱-质谱联用技术对海芒果叶挥发油化学成分进行分析,用气相色谱面积归一化法测定了各成分的相对百分含量。经毛细管色谱分离鉴定了13个化合物。研究了挥发油对赤拟谷盗的活性:触杀活性测定发现挥发油对赤拟谷盗48 h的LC50为1.0067 mL/L;忌避活性测定发现1 mL/L浓度在12~48 h内忌避率都在80%以上;熏蒸活性测定发现24、48、72 h的LC50分别为2.0207、1.7450、1.0160mL/L;     

小果博落回中2种杀虫活性成分的分离及鉴定

以粘虫(Mythimna separata)3龄幼虫为试虫,采用生物活性示踪法从小果博落回(Macleaya microcarpa)乙醇提取物中分离纯化出2种活性成分,经MS1、H-NMR1、3C-NMR分析鉴定为二氢血根碱和二氢白屈菜红碱。采用小叶碟添加法测试了2种化合物对粘虫3龄幼虫的拒食及毒杀活性。结果表明,2种化合物对粘虫3龄幼虫均具有较高的拒食活性,48 h的拒食AFC50分别为0.168和0.231 mg.mL-1,同时,二氢血根碱对粘虫3龄幼虫具有一定的毒杀活性,96 h的LC50为0.085 mg.mL-1。分析认为二氢血根碱可能是小果博落回的主要杀虫活性成分之一。     

海洋真菌Aspergillus niger XJJ-3中萘并吡喃酮类化合物结构及生物活性

【背景】萘并吡喃酮类化合物生物活性多样,是真菌Aspergillusniger中特征次生代谢产物。【目的】研究分离自海洋滩涂土壤的真菌Aspergillus niger XJJ-3中萘并吡喃酮类化合物结构及其抗菌和卤虫致死活性。【方法】以TLC分析为导向,综合运用多种色谱和光谱方法分离和鉴定萘并吡喃酮类化合物。采用微量稀释法测试化合物的抗菌和卤虫致死活性。【结果】从真菌A.niger大米发酵产物中共分离得到6个萘并吡喃酮类化合物,鉴定为RubrofusarinB(1)、Flavasperone (2)、Aurasperone A (3)、Asperpyrones C (4)、Asperpyrones B (5)和Fonsecinone A (6)。抗菌活性实验结果表明,化合物1-6对致病菌S. aureus ATCC33591、29213、E. faecium ATCC35667和V.parahemolyticus表现出不同程度的抑制活性,其中化合物2和4对S.aureus ATCC33591表现出较强抑制活性(MIC分别为43.7μmol/L和21.9μmol/L),化合物3对E.faecium ATCC35667抑制活性较强(MIC为21.9μmol/L)。卤虫致死活性实验结果表明,化合物1-6均表现出一定的卤虫致死活性,其中化合物2和3活性显著(LD50分别为35.0μmol/L和8.8μmol/L)。【结论】菌株XJJ-3可产生结构丰富的萘并吡喃酮类化合物,化合物1-6存在不同程度的抗菌和卤虫致死活性,该研究可为抗菌和细胞毒类药物的研发提供参考。     

酸模内生镰刀菌HU0298抗MRSA活性代谢成分

从酸模Rumex acetosa内生真菌Fusarium sp.HU0298玉米发酵物的活性流分中分离鉴定了一个主要成分:亚油酸;结合活性流分的气相色谱(GC)组分分析和活性评价发现亚油酸是该发酵物的主要抗耐甲氧西林金黄色葡萄球菌(MRSA)成分;通过对亚油酸和多个其他脂肪酸标准品的活性测试探究了脂肪酸化学结构和与抗M...     

木榄根际土壤来源的曲霉属真菌F5及其抗菌活性代谢产物

将一株分离自木榄根际土壤的菌株F5鉴定为曲霉属环绕组真菌成员,其在形态学特征和ITS序列上与Aspergillus ochraceopetaliformis极为相似。该菌株在改良葡萄糖蛋白胨酵母培养基(GPYM)中28℃下160r/min发酵7d后的产物具有明显的抑菌活性。利用色谱方法从菌株F5的发酵产物中分离鉴定到2种化合物:(R)-(-)-mellein(Ⅰ)和flavacol(Ⅱ),其中,flavacol对枯草芽孢杆菌的生长具有明显的抑制作用,最低抑菌浓度(MIC)为32mg/L,而mellein对金黄色葡萄球菌和枯草芽孢杆菌的生长均无明显的抑制活性。     

鲫寄生7种指环虫的形态学和分子鉴定

指环虫(Dactylogyrus sp.)是鲫(Carassius auratus)鳃部重要的致病寄生虫, 为调查鲫的指环虫种类, 采用形态学与分子生物学相结合的方法, 对梁子湖鲫的单殖吸虫进行了种类鉴定。通过对指环虫后吸器几丁质结构的形态特征描述和测量, 发现鳃部共有7种指环虫, 分别鉴定为坏鳃指环虫(D. vastator)、中型指环虫(D. intermedius)、弧形指环虫(D. arcuatus)、弓茎指环虫(D. baueri)、美丽指环虫(D. formosus)、望外指环虫(D. inexpeatatus)及叉茎指环虫(D. dulkeiti)。中型指环虫、美丽指环虫和叉茎指环虫与GenBank中相应指环虫的18S+ITS1+5.8S rDNA序列的相似性均高于99.0%, 弧形指环虫的基因序列为首次提交。而坏鳃指环虫与GenBank中相应的指环虫序列相似度仅有96.37%, 遗传距离分析显示, 坏鳃指环虫的种内遗传距离较大(0.004—0.058), 但小于坏鳃指环虫与中型指环虫的种间遗传距离(0.046—0.064)。研究重新描述我国鲫7种指环虫主要形态学分类特征, 并提供分子分类数据, 为鲫寄生指环虫的种类鉴定提供参考依据。     

黄皮种子提取物对斜纹夜蛾幼虫的杀虫活性及有效成分鉴定

【目的】测定黄皮Clausena lansium种子提取物对斜纹夜蛾Spodoptera litura幼虫的拒食活性,对有效成分进行分离、鉴定,并进一步测定其拒食活性、生长发育抑制活性及细胞毒性,为筛选斜纹夜蛾生态防治植物源杀虫剂提供依据。【方法】采用叶蝶法测定黄皮种子甲醇提取物及其石油醚、乙酸乙酯、正丁醇和水4种溶剂萃取物对斜纹夜蛾3龄幼虫的非选择性拒食活性和生长发育抑制活性;用硅胶柱层析进行石油醚萃取物和乙酸乙酯萃取物拒食活性成分分离;用核磁共振谱(NMR)进行拒食有效成分结构鉴定;用MTT法测定拒食活性成分对SL细胞毒性。【结果】黄皮种子甲醇提取物对斜纹夜蛾3龄幼虫具有较强的拒食活性,活性成分主要分布于石油醚相和乙酸乙酯相中;石油醚相和乙酸乙酯相经硅胶柱层析分离得10个馏分,以黄色晶体馏分2的拒食活性最强;经分离纯化及核磁共振氢谱和碳谱鉴定,黄皮新肉桂酰胺B(lansiumamide B)为主要的拒食活性成分,对斜纹夜蛾3龄幼虫48 h拒食中浓度为214.95μg/m L,同时具有较强的细胞毒性,对SL细胞48 h抑制中浓度为10.09μg/m L。【结论】黄皮种子提取物对斜纹夜蛾幼虫具有较强的拒食活性及细胞毒性,黄皮新肉桂酰胺B是主要活性成分之一,作为植物源杀虫剂开发具有较好的发展前景。     

岩木瓜化学成分的分离、结构鉴定与杀虫活性

为明确岩木瓜Ficus tsiangii Merr. ex Corner的杀虫活性成分及杀虫活性,利用活性跟踪分离技术,通过硅胶柱层析、薄层层析及葡聚糖凝胶等手段对岩木瓜茎和根皮的化学成分进行了分离、纯化,结合化合物理化性质和波谱数据对其结构进行了鉴定.结果表明,从岩木瓜中分离得到4个生物活性化合物,分别为β-香树脂醇乙酸酯、蒲公英赛酮、柯依利素及齐墩果酸.利用胃毒法测定了这些化合物（500μg/g糖）对家蝇Musca domestica成虫的生物活性,其中蒲公英赛酮处理试虫48 h后的校正死亡率达到83.33%,表现出较强杀虫活性,并进一步测定了其对试虫的毒力.结果表明,蒲公英赛酮处理家蝇成虫48 h后表现出较强毒力,其LC₅₀值为89.82μg/g糖,略低于对照药剂鱼藤酮毒力（LC₅₀值为67.58μg/g糖）.因此,蒲公英赛酮值得进一步深入研究.     

一株毒死蜱降解新菌株Sphingopyxis terrae R17的分离鉴定及降解特性

从农药厂排污沟污泥中分离到一株能降解毒死蜱的新菌株,命名为R17,经生理生化和16S rDNA序列同源性分析,鉴定为Sphingopyxis terrae.R17可以利用毒死蜱作为唯一碳源生长,该菌株的最适生长温度为35℃、最适pH为7～8,在此条件下培养28 h后,菌落浓度达9.18×108cfu/mL.研究了该菌在...     

A kinetic study of the gill (Na+, K+)-ATPase, and its role in ammonia excretion in the intertidal hermit crab, Clibanarius vittatus

To better comprehend the role of gill ion regulatory mechanisms, the modulation by Na(+), K(+), NH(4)(+) and ATP of (Na(+), K(+))-ATPase activity was examined in a posterior gill microsomal fraction from the hermit crab, Clibanarius vittatus. Under saturating Mg(2+), Na(+) and K(+) concentrations, two well-defined ATP hydrolyzing sites were revealed. ATP was hydrolyzed at the high-affinity sites at a maximum rate of V=19.1+/-0.8 U mg(-1) and K(0.5)=63.8+/-2.9 nmol L(-1), obeying cooperative kinetics (n(H)=1.9); at the low-affinity sites, hydrolysis obeyed Michaelis-Menten kinetics with K(M)=44.1+/-2.6 mumol L(-1) and V=123.5+/-6.1 U mg(-1). Stimulation by Na(+) (V=149.0+/-7.4 U mg(-1); K(M)=7.4+/-0.4 mmol L(-1)), Mg(2+) (V=132.0+/-5.3 U mg(-1); K(0.5)=0.36+/-0.02 mmol L(-1)), NH(4)(+) (V=245.6+/-9.8 U mg(-1); K(M)=4.5+/-0.2 mmol L(-1)) and K(+) (V=140.0+/-4.9 U mg(-1); K(M)=1.5+/-0.1 mmol L(-1)) followed a single saturation curve and, except for Mg(2+), obeyed Michaelis-Menten kinetics. Under optimal ionic conditions, but in the absence of NH(4)(+), ouabain (K(I)=117.3+/-3.5 mumol L(-1)) and orthovanadate inhibited up to 67% of the ATPase activity. The inhibition studies performed suggest the presence of F(0)F(1), V- and P-ATPases, but not Na(+)-, K(+)- or Ca(2+)-ATPases as contaminants in the gill microsomal preparation. (Na(+), K(+))-ATPase activity was synergistically modulated by NH(4)(+) and K(+). At 20 mmol L(-1) K(+), a maximum rate of V=290.8+/-14.5 U mg(-1) was seen as NH(4)(+) concentration was increased up to 50 mmol L(-1). However, at fixed NH(4)(+) concentrations, no additional stimulation was found for increasing K(+) concentrations (V=135.2+/-4.1 U mg(-1) and V=236.6+/-9.5 U mg(-1) and for 10 and 30 mmol L(-1) NH(4)(+), respectively). This is the first report to detail ionic modulation of gill (Na(+), K(+))-ATPase in C. vittatus, revealing an asymmetrical, synergistic stimulation of the enzyme by K(+) and NH(4)(+), as yet undescribed for other (Na(+), K(+))-ATPases, and should provide a better understanding of NH(4)(+) excretion in pagurid crabs.     

K+ and NH4(+) modulate gill (Na+, K+)-ATPase activity in the blue crab, Callinectes ornatus: fine tuning of ammonia excretion

To better comprehend the mechanisms of ionic regulation, we investigate the modulation by Na+, K+, NH4(+) and ATP of the (Na+, K+)-ATPase in a microsomal fraction from Callinectes ornatus gills. ATP hydrolysis obeyed Michaelis-Menten kinetics with KM=0.61+/-0.03 mmol L(-1) and maximal rate of V=116.3+/-5.4 U mg(-1). Stimulation by Na+ (V=110.6+/-6.1 U mg(-1); K0.5=6.3+/-0.2 mmol L(-1)), Mg2+ (V=111.0+/-4.7 U mg(-1); K0.5=0.53+/-0.03 mmol L(-1)), NH4(+) (V=173.3+/-6.9 U mg(-1); K0.5=5.4+/-0.2 mmol L(-1)) and K+ (V=116.0+/-4.9 U mg(-1); K0.5=1.5+/-0.1 mmol L(-1)) followed a single saturation curve, although revealing site-site interactions. In the absence of NH4(+), ouabain (K(I)=74.5+/-1.2 micromol L(-1)) and orthovanadate inhibited ATPase activity by up to 87%; the inhibition patterns suggest the presence of F0F1 and K+-ATPases but not Na+-, V- or Ca2+-ATPase as contaminants. (Na+, K+)-ATPase activity was synergistically modulated by K+ and NH4(+). At 10 mmol L(-1) K+, increasing NH4(+) concentrations stimulated maximum activity to V=185.9+/-7.4 U mg(-1). However, at saturating NH4(+) (50 mmol L(-1)), increasing K+ concentrations did not stimulate activity further. Our findings provide evidence that the C. ornatus gill (Na+, K+)-ATPase may be particularly well suited for extremely efficient active NH4(+) excretion. At elevated NH4(+) concentrations, the enzyme is fully active, regardless of hemolymph K+ concentration, and K+ cannot displace NH4(+) from its exclusive binding sites. Further, the binding of NH4(+) to its specific sites induces an increase in enzyme apparent affinity for K+, which may contribute to maintaining K+ transport, assuring that exposure to elevated ammonia concentrations does not lead to a decrease in intracellular potassium levels. This is the first report of modulation by ammonium ions of C. ornatus gill (Na+, K+)-ATPase, and should further our understanding of NH4(+) excretion in benthic crabs.     

荞麦组织培养及高频植株再生体系的建立

通过对荞麦(Fagopyrum esculentum Moench)不同外植体、不同激素配比的比较研究,建立了荞麦离体培养高效植株再生体系。荞麦子叶切段在含2．0 mg/L 2,4-D和1．0 mg/L 6-BA的MS培养基上愈伤组织诱导率为89．6％,而下胚轴切段在含2．0 mg/L 2,4-D和1．0-2．0 mg/L 6-BA MS培养基上愈伤组织诱导率高达100％。在2．0 mg／L 6-BA、0．1 mg,L IAA和1 mg／L KT的MS培养基上通过愈伤组织间接分化或外植体直接分化形成不定芽。来自子叶和下胚轴的愈伤组织的分化率分别为42．5％和73．6％,下胚轴的分化率明显高于子叶。将生长状态良好的不定芽转至含1．0 mg/L IBA和0．5mg/L NAA的1/2 MS培养基上生根,生根率达到100％。再生植株移栽到盆土中,成活率达91．6％,并且生长状态和特征均表现正常。     

四倍体刺槐无性系K2和K3的组织培养

1997年,北京林业大学从韩国引进了具有速生和饲料用途的刺槐(Robinia pseudoacacia L.)四倍体优良无性系,目前已在全国各省区试推广.与普通刺槐相比,四倍体刺槐具有叶大、速生等优点,且较普通刺槐有更强的适应性,耐干旱、贫瘠、烟尘及盐碱能力强,成林快,是水土保持、防风固沙及退耕还林的良好树种,可作为西北地区造林的先锋树种.     

花生幼叶不定芽诱导与快速繁殖

以花生品种‘粤油7号’6~8 d龄幼叶为外植体进行植株再生研究。结果表明,外植体在MS+0.6 mg/L NAA+8 mg/L 6-BA+1 mg/L AgNO₃+3 mg/L Gln培养基上,诱导不定芽效果好,经两次继代培养出芽率达81.03%,每个外植体平均出芽数达5.79个。经伸长培养基MS+2 mg/L 6-BA+4 mg/L GA₃培养,不定芽伸长长度达1.0~2.0 cm。试管苗在培养基1/2 MS+0.5 mg/L NAA+3 mg/L IBA上生根率达86.15%,不定根粗而长,有侧根,移栽成活率达90%,结实率100%。     

镉在黑藻叶细胞中的亚显微定位分布及毒害效应分析

Aquatic plants are known to accumulate and bioconcentrate heavy metals. In this study, aquatic vascular plant Hydrilla verticillata (L.f.) Royle was cultivated in water containing elevated concentrations of cadmium (up to 10 mg/L) for 7 d, the accumulation, subcellular distribution, ultrastructural localization, chemical form, toxic effects on mineral nutrient absorption of cadmium, photosynthesis rate and respiration rate were studied. It was found that H. verticillata fronds was able to accumulate cadmium, the bioconcentration factor was 193-307; subcellular fraction analysis revealed that cadmium major accumulated in cell wall (61.66%-52.00%) with decrease trends, the content of Cd enhanced in soluble fraction and remained stable in organelles, with the augment of pollutant concentration. The Cd levels occurred in different parts of leaf cell with the following sequence: cell wall > soluble fraction > organelles. Ultrastructural localization of cadmium with sulfide-silver method showed that Cd appeared in cell wall, chloroplast, nucleus and vacuole. Sequential extraction indicated that the ratio of different cadmium chemical form was different markedly, of which NaCl extractable Cd was predominated as compared with the other 5 forms; which could be seen in the following order: F(NaCl) > F(HAc) >F(Water) > F(Ethanol) > F(HCl) > F(Residue). The mineral nutrient absorption was also affected by cadmium stress, it increased the absorption of Ca, Mn, Cu, and Fe; but reduced that of P and K. Cd had a strong inhibitive effect on photosynthesis rate and respiration rate. The results suggested that the toxic symptoms of plant showed an evident correlation between dose and effect; the ultrastructural damage was closely related to the distribution of Cd. The conclusion could be reached that the death of plant was resulted from destruction of structure foundation of physiological function, unbalance of ion equilibrium and disorder of physiological metabolism.     

佳禾早占成熟种胚高效率组织培养方法的研究（简报）

In order to improve the embryogenic callus induction rate and the regeneration rate of JiaHe-ZaoZhan rice, the influence of different factors were investigated, media with different hormones were used. Induction medium was supplemented with 1.5 mg/L 2,4-D + 3 mg/L NAA + 0.1 mg/L KT + 1 mg/L phytic acid + 20 mg/L PAA. Embryogenic call were treated under the condition of 25 degrees C before transferring to regeneration medium, the regeneration medium contained 0.5 mg/L 6-BA + 3 mg/L NAA + 0.5 mg/L KT + 1 mg/L phytic acid. The experiment results indicated that the hormone treatments had certain effects on the callus induction. Under the optimal medium, culture condition and the hormone treatments, the embryogenic callus induction could reach over 95%, and dry treatment of embryogenic callus had been found to increase the frequency of plant regeneration, significantly the plant regeneration rate could reach over 80%. Transplanted into pots, the young plants grew well. Then a experimental system with stability and high regenerating efficiency has been established for the mature seeds of rice (JiaHe-ZaoZhan).     

羊草成熟胚诱导愈伤组织及植株再生系统的优化

羊草(Leymus chinensis)为异源四倍体禾本科牧草, 利用成熟胚诱导愈伤组织获得再生植株的效率极低, 难以运用遗传转化方法进行品种改良。我们以羊草成熟胚为外植体, 使用适宜羊草愈伤组织生长的新型培养基配方, 筛选诱导愈伤组织、不定芽分化及生根阶段的最适植物激素浓度、光照和温度条件, 从而优化羊草成熟胚的组织培养方案。研究结果表明, 羊草成熟胚诱导阶段2,4-D的最适浓度为2.0 mg·L ^-1, 变温暗培养, 诱导率可达74.1%; 分化阶段6-BA和NAA的最适浓度均为1.0 mg·L ^-1, 分化率可达57.1%; 生根阶段NAA的最适浓度为0.25 mg·L ^-1, 移栽后成活率为100%。     

播娘蒿下胚轴高频率再生植株因素的研究

以播娘蒿（Descurainia sophia)下胚轴为外植体,研究影响其分化的若干因素。结果表明：用附加2,4－D的培养基,对下胚轴切段预培养5d可提高分化频率;1.7mg/L AgNO3对分化出芽有很大促进作用,最佳激素组合为2.0mg/L 6-BA 0.2mg/L NAA;黄化苗的下胚轴比绿苗的下胚轴对激素反应更敏感,最高分化频率可达86.05%。再生芽转至1／2MS 0.5mg/L NAA 0.5mg/L IBA的培养基中,生根率100％。