鸭跖草叶点霉粗毒素的提取方法和产毒条件的研究

以石油醚、乙酸乙酯、四氯化碳三种极性不同的溶剂对鸭跖草叶点霉病原菌的菌丝和培养液进行萃取,获取粗毒素。结果表明,叶点霉菌产生的毒素既有胞外毒素,又有胞内毒素,且用极性中等的乙酸乙酯萃取效果最好。大豆培养基和PSK分别是适合菌株生长和毒素分泌的固体培养基和液体培养基。确定有利于叶点霉产毒的温度为32℃、培养时间为14d、培养方式为150r/min振荡培养。     

芸薹链格孢致病毒素分析Ⅰ.腐败菌素B的分离提纯和结构鉴定

芸薹链格孢（Alternariabrassicae）在PD液体培养基中黑暗培养20d,过滤获得培养滤液,经乙酸乙酯萃取、45℃减压浓缩得AB-粗毒素。AB-粗毒素经HPLC分析,在λ＝206nm波长下具有Ⅰ、Ⅱ、Ⅲ和Ⅳ4个明显的吸收峰。组分Ⅲ的红外吸收光谱、FAB／MASS和1H-NMR与已报道的腐败菌素B基本一致,由此确定组分Ⅲ为腐败菌素B。试验发现,芸薹链格孢的培养滤液、AB-粗毒素和毒素组分Ⅲ均能造成白菜叶片黄化、萎蔫和坏死。     

猪苓发酵液抑菌活性物质的性质研究

研究猪苓发酵液中抑菌活性成分的性质,以期将为猪苓的药用机理的研究提供部分理论依据。以大肠埃希菌、枯草芽胞杆菌、金黄色葡萄球菌、热带假丝酵母、酿酒酵母、小麦赤霉为靶标菌,研究发酵液的抑菌作用;用不同极性有机溶剂萃取活性物质,检测萃取液抑菌效果;并探索了不同温度和pH下对发酵液活性的影响;利用捷克八溶剂系统和紫外扫描对物质类型进行了初步确定。结果表明：猪苓发酵液对细菌有抑菌活性;活性物质对酸碱敏感且热不稳定,可被乙酸乙酯、三氯甲烷、正丁醇等有机溶剂萃取,随萃取极性增大萃取能力增强;紫外扫描其萃取浓缩液,表明在λ210nm处有一典型吸收峰,与酯肽类抗菌素的紫外图谱相似;捷克八溶剂系统纸层析结果显示抑菌物质为非水溶性Ⅱ型抗生素。猪芩发酵液中存在抗生素类物质,但稳定性差。在猪苓的以多糖为主要药用成分的应用过程中不发挥重要作用。     

藏药熏倒牛提取物的抑菌杀虫活性研究

为了探讨藏药熏倒牛乙醇提取物不同极性溶剂萃取部位的抑菌杀虫活性,将熏倒牛乙醇提取物依次用石油醚、乙酸乙酯、正丁醇萃取,所得各萃取部位及水余液部位通过抑菌圈法测定抑菌活性部位,对活性部位采用二倍稀释法测定最低抑菌浓度,采用改良任氏法测定杀灭滴虫活性部位及最低有效杀虫浓度。结果表明熏倒牛乙醇提取物的乙酸乙酯部位对金黄色葡萄球菌、铜绿假单胞菌和阴沟肠杆菌有强抑制作用,最低抑菌浓度为0.125 mg/m L,对变形杆菌、粪肠球菌和白色念珠菌的抑制作用也比较强,最低抑菌浓度为0.25 mg/m L。石油醚部位和乙酸乙酯部位对阴道滴虫有明显抑制作用,最低有效杀虫浓度分别为0.5、0.25 mg/m L。说明熏倒牛乙醇提取物的乙酸乙酯萃取部位有较强的抑菌杀虫作用,是熏倒牛的抑菌杀虫活性部位。     

藏药熏倒牛提取物的抑菌杀虫活性研究北大核心CSCD

为了探讨藏药熏倒牛乙醇提取物不同极性溶剂萃取部位的抑菌杀虫活性,将熏倒牛乙醇提取物依次用石油醚、乙酸乙酯、正丁醇萃取,所得各萃取部位及水余液部位通过抑菌圈法测定抑菌活性部位,对活性部位采用二倍稀释法测定最低抑菌浓度,采用改良任氏法测定杀灭滴虫活性部位及最低有效杀虫浓度。结果表明熏倒牛乙醇提取物的乙酸乙酯部位对金黄色葡萄球菌、铜绿假单胞菌和阴沟肠杆菌有强抑制作用,最低抑菌浓度为0.125 mg/m L,对变形杆菌、粪肠球菌和白色念珠菌的抑制作用也比较强,最低抑菌浓度为0.25 mg/m L。石油醚部位和乙酸乙酯部位对阴道滴虫有明显抑制作用,最低有效杀虫浓度分别为0.5、0.25 mg/m L。说明熏倒牛乙醇提取物的乙酸乙酯萃取部位有较强的抑菌杀虫作用,是熏倒牛的抑菌杀虫活性部位。     

一株镰孢霉发酵产物不同极性提取物对兔膝软骨细胞的影响

通过研究一株内生梨孢镰孢霉(Fusarium poae)发酵产物中不同极性提取物对兔膝软骨细胞的影响,初步了解其中毒性物质的基本性质,为进一步探讨真菌毒素在大骨节病发病中的可能作用以及分离新的潜在致病物质打下良好基础。本研究以预实验中筛选出的对软骨细胞有较强毒损作用的F.poae菌株进行摇瓶培养;发酵产物先用75%乙醇进行提取,再将乙醇总提取物用不同极性的溶剂进行萃取;将所得各种次级提取物分别作用于体外培养的兔膝软骨细胞,检测与软骨细胞损伤相关的指标,其中细胞存活率采用噻唑蓝(MTT)显色法,Ⅱ型胶原蛋白及蛋白聚糖的含量分别采用免疫组化法和甲苯胺蓝染色法,二者相应的mRNA表达量用半定量RT-PCR进行检测。结果发现,不同极性溶剂提取所得的石油醚、乙醚、乙酸乙酯和水提取物,都能在不同程度上造成培养兔软骨细胞的存活率、Ⅱ型胶原蛋白和蛋白聚糖的含量以及相应mRNA的表达量降低;毒性强弱有随溶剂极性增强而减弱的趋势,以石油醚分部的综合毒损作用最强,其后依次为乙醚、乙酸乙酯和水提取物。镰孢霉发酵产物的各种不同极性提取物中,都存在对软骨细胞相关指标造成程度不等毒损作用的物质。这些结果支持我们关于大骨节病的发病可能和多种真菌毒素的综合作用相关的观点。     

纯培养拟茎点霉属真菌的产孢条件

对8种拟茎点霉纯培养下的产孢条件进行了筛选和比较。结果表明,拟茎点霉产孢的最佳培养基为苜蓿煎汁+Czapek培养基,其次为燕麦片琼脂培养基和苜蓿杆+水琼脂培养基;最适温度范围为22~25℃;最佳光照时间为每天12h(日光灯40W,与培养物间的距离约为30cm);合适的pH值范围为5.6~6.8。     

出芽短梗霉在三种不同氮源的培养基中多糖积累以及形态变化

本研究旨在阐明出芽短梗霉在不同氮源培养基中形态和胞外多糖的积累及化学成分变化。采用摇瓶法培养出芽短梗霉。三种培养基的氮源分别为硝酸钠(培养基1,M1)、硫酸氨、酵母膏(培养基2,M2)和硫酸氨、蛋白胨和酵母膏(培养基3,M3)。M1培养基中,菌丝体和单细胞的生物量积累均比M2、M3低,但胞外多糖的产量则等于甚至略超过M2和M3。在指数生长的前期,白色菌丝体和酵母状细胞状态占优势。指数生长的后期,以厚垣孢子、肿大细胞和黑色菌丝体占优势。胞外多糖都能为茁霉多糖酶水解为麦芽糖和麦芽三糖,说明这些多糖的化学组成都具有(1→4,1→6)-α结构的茁霉多糖。但M1中产生的茁霉多糖结构单元为麦芽糖和麦芽三糖,且二者比例相当。M2中茁霉多糖的麦芽糖结构单元明显减少,而M3中144h后麦芽糖结构单元完全消失。这似乎表明氧化性的氮源和低溶解氧水平可能是造成茁霉多糖结构单元同时具有麦芽糖和麦芽三糖的原因。     

华根霉固态与液态培养产胞外蛋白的比较蛋白质组学分析

【目的】考察固态和液态两种培养方式对丝状真菌华根霉(Rhizopus chinensis)CCTCC M201021产胞外蛋白的影响,以加深对微生物固、液态培养特异性产酶的认识。【方法】利用成分相同的培养基对华根霉分别进行平板固态培养和液态培养,提取华根霉所产胞外蛋白,采用二维凝胶电泳(2-DE)结合质谱分析,分离鉴定差异蛋白。【结果】固态培养下华根霉所产胞外蛋白的蛋白酶活性是液态培养的9.2倍。胞外蛋白质组数据分析表明,华根霉固态和液态培养所产胞外蛋白存在显著差异,其中约70%是固态和液态培养下各自产生的特有蛋白。质谱鉴定进一步表明,固、液态培养对华根霉产胞外蛋白的种类和表达量都有显著影响,其中水解酶类所占比例较大,主要是与蛋白质降解相关的蛋白。【结论】固态和液态不同培养方式影响了华根霉产胞外蛋白的组成,有些基因只在特定培养方式下表达。固态培养下华根霉产胞外蛋白酶种类相对更多以及大部分蛋白酶的上调表达,可能是固态培养下胞外蛋白酶活性很高的原因。研究结果提示需要注意固液态不同培养方式下丝状真菌胞外酶的筛选和生产可能存在的不一致性。     

中国弯颈霉新种及产环孢菌素的研究

对云南省迪庆藏族自治州产的冬虫夏草 Cordyceps sinensis(Berk.)Sacc.进行分离获一纯种,经培养鉴定确为弯颈霉属 Tolypocladium w.Gams 一新种,命名为中国弯颈霉 To-lypocladium sinense c.L.Li sp.nov.。它在几种琼脂培养基上生长形成瓶梗及瓶梗孢于,瓶梗基部呈球形或椭圆形膨大,瓶颈细长而弯曲,瓶梗孢子球形至卵形。其形态特征及生活习性与弯颈霉属其它种类显然不同,故定为一新种。它在蛋白胨葡萄糖培养液中,温度26℃,pH5.2,摇瓶振荡培养12天。发酵液用乙酸乙酯萃取,减压蒸馏,从每升发酵液中获50—80mg 环孢菌素粗品。对几种半知真菌显示了明显的拮抗作用。     

Astragalar morphology of late Eocene anthropoids from the Fayum Depression (Egypt) and the origin of catarrhine primates

The phylogenetic relationships of the late Eocene anthropoids Catopithecus browni and Proteopithecus sylviae are currently a matter of debate, with opinion divided as to whether these taxa are stem or crown anthropoids. The phylogenetic position of Catopithecus is of particular interest, for, unlike the highly generalized genus Proteopithecus, this taxon shares apomorphic dental and postcranial features with more derived undoubted catarrhines that appear in the same region 1-2 Ma later. If these apomorphies are homologous and Catopithecus is a stem catarrhine, the unique combination of plesiomorphic and apomorphic features preserved in this anthropoid would have important implications for our understanding of the crown anthropoid morphotype and the pattern of morphological character transformations that occurred during the early phases of stem catarrhine evolution.Well-preserved astragali referrable to Proteopithecus, Catopithecus, and the undoubted early Oligocene stem catarrhine Aegyptopithecus have provided additional morphological evidence that allows us to further evaluate competing hypotheses of interrelationships among Eocene-Oligocene Afro-Arabian anthropoids. Qualitative observations and multivariate morphometric analyses reveal that the astragalar morphology of Proteopithecus is very similar to that of early Oligocene parapithecids and living and extinct small-bodied platyrrhines, and strengthens the hypothesis that the morphological pattern shared by these taxa is primitive within crown Anthropoidea. In contrast, Catopithecus departs markedly from the predicted crown anthropoid astragalar morphotype and shares a number of apomorphic features (e.g., deep cotylar fossa, laterally projecting fibular facet, trochlear asymmetry, mediolaterally wide astragalar head) with Aegyptopithecus and Miocene-Recent catarrhines. The evidence from the astragalus complements other independent data from the dentition, humerus and femur of Catopithecus that support this taxon's stem catarrhine status, and we continue to maintain that oligopithecines are stem catarrhines that constitute the sister group of a clade containing propliopithecines and Miocene-Recent catarrhines.     

中国异极衣科地衣二新记录种

该文综合运用形态学、解剖学和化学等方法对山东大型地衣进行分类研究,发现了两个中国新记录种,即德氏蜂窝衣(Heppia despreauxii)和多孢小极衣(Lichinella myriospora).德氏蜂窝衣隶属于蜂窝衣属(Heppia),生于光线充足且裸露的土壤上,主要识别特征为下皮层缺失、子实层IKI+蓝色;多...     

藏药多刺绿绒蒿种子萌发特性研究

多刺绿绒蒿(Meconopsis horridula)为罂粟科绿绒蒿属一年生草本植物,是一种极具观赏价值和药用价值的高山植物,目前处于濒危状态,因此研究多刺绿绒蒿种子的萌发特性对其种子育苗及人工栽培具有重要意义。为了提高多刺绿绒蒿的种子发芽率,该研究以多刺绿绒蒿的种子为材料,分析了不同消毒剂、浸种时间、温度和外源植物激素对种子萌发特性的影响。结果表明:(1)最适消毒方法为75%乙醇1 min+3%H2O25 min,最适浸种时间为24 h,最适温度和光照条件为20℃/10℃(光照12 h/黑暗12 h),用无菌水浸种后的种子发芽率为49.67%。(2) GA_3100～600 mg·L~(-1)和NAA 5～30 mg·L~(-1)可以提高种子的发芽率、发芽势和发芽指数,缩短发芽启动时间和发芽持续时间,对种子的萌发有促进作用。(3) 6-BA 5 mg·L~(-1)和10 mg·L~(-1)对种子的萌发有一定的促进作用,但不显著,6-BA浓度≥15 mg·L~(-1)则抑制种子的萌发。(4)用GA3500 mg·L~(-1)浸种后的种子发芽指标最好,发芽率、发芽势和发芽指数分别为69.67%、33.00%、4.51,种子的发芽起始时间和发芽持续时间分别为10.67 d、11.67 d。     

scabrous Modifies Epithelial Cell Adhesion and Extends the Range of Lateral Signalling during Development of the Spaced Bristle Pattern in Drosophila

The role of scabrous (sca) in the evenly spaced bristle pattern of Drosophila is explored. Loss-of-function of sca results in development of an excess of bristles. Segregation of alternately spaced bristle precursors and epidermal cells from a group of equipotential cells relies on lateral inhibition mediated by Notch and Delta (Dl). In this process, presumptive bristle precursors inhibit the neural fate of neighbouring cells, causing them to adopt the epidermal fate. We show that Dl, a membrane-bound ligand for Notch, can inhibit adjacent cells, in direct contact with the precursor, in the absence of Sca. In contrast, inhibition of cells not adjacent to the precursor requires, in addition, Sca, a secreted molecule with a fibrinogen-related domain. Over-expression of Sca in a wild-type background, leads to increased spacing between bristles, suggesting that the range of signalling has been increased. scabrous acts nonautonomously, and we present evidence that, during bristle precursor segregation, Sca is required to maintain the normal adhesive properties of epithelial cells. The possible effects of such changes on the range of signalling are discussed. We also show that the sensory organ precursors extend numerous fine cytoplasmic extensions bearing Dl molecules, and speculate on a possible role for these structures during signalling.     

中国兰科二新记录种

兰科植物资源调查是掌握地区兰科本底资料的基础,对研究兰科植物的地理分布和资源多样性具有重要意义.该文报道了分别产自中国西藏自治区墨脱县和巴宜区的石豆兰属(Bulbophyllum Thou.)中国分布新记录种——尼泊尔大苞兰(B.raskotii J.J.Verm.,Schuit.&de Vogel)和曲唇兰属[Pan...     

不同光质对白及组培苗生长及光合特性的影响

白及的自然繁殖率极低,组培育苗是其种苗繁殖的主要方式之一.为探索提高白及组培育苗质量及缩短育苗周期的高效人工光环境,该文以紫花白及(Bletilla striata)为试验材料,研究LED光质对白及组培苗的生长和光合特性的影响.结果表明:提高红蓝光组合中的蓝光占比,有利于促进白及组培苗的生长和生物量的积累,而白及的球茎...     

荨麻科三新种

该文描述了荨麻科三新种:(1)自中国重庆市发现的荨麻科荨麻属一新种,城口荨麻。此种与异株荨麻有亲缘关系,区别特征为此种的茎被少数刺毛,叶片多为心形,雄、雌花序均不分枝,瘦果在中央稍凹陷。(2)自中国广西发现的荨麻科赤车属一新种,来宾赤车。此种与特产云南东南部的富宁赤车相近缘,与后者的区别在于本种茎的毛开展或向上弯曲,叶片长椭圆形,基部斜楔形,雌花具3~4枚花被片,其中1~2枚较大花被片在背面顶端具一长筒状突起。(3)自缅甸北部发现的荨麻科楼梯草属一新种,克钦楼梯草。此种在体态上与骤尖楼梯草甚为相似,与后者的区别在于本种的每一茎节具正常叶和一退化叶,托叶狭披针状条形和无脉,雌总苞苞片无角状突起,雌小苞片较大,呈楔状长圆形,雌花具一小花被片,以及雌蕊具一宽倒卵球形柱头。     

Stratigraphy, artefact industries and hominid associations for Sterkfontein, member 5

A revised stratigraphy for the early hominid site of Sterkfontein (Gauteng Province, South Africa) reveals a complex distribution of infills in the main excavation area between 2.8 and 1.4 m.y.a, as well as deposits dating to the mid to late Pleistocene. New research now shows that the Member 4 australopithecine breccia (2.8-2.6 Ma) extends further west than was previously thought, while a late phase of Member 4 is recognized in a southern area. The artefact-bearing breccias were defined sedimentologically as Member 5, but one supposed part of these younger breccias, the StW 53 infill, lacks in situ stone tools, although it does appear to post-date 2.6 Ma when artefacts first appear in the archaeological record. The StW 53 hominid, previously referred to Homo habilis, is here argued to be Australopithecus. The first artefact-bearing breccia of Member 5 is the Oldowan Infill, estimated at 2-1.7 Ma. It occupies a restricted distribution in Member 5 east and contains an expedient, flake-based tool industry associated with a few fossils of Paranthropos robustus. An enlarged cave opening subsequently admitted one or more Early Acheulean infills associated in Member 5 west with Homo ergaster. The artefacts attest to a larger site accumulation between ca. 1.7 and 1.4 Ma, with more intensive use of quartzite over quartz and a subtle but important shift to large flakes and heavier-duty tools. The available information on palaeoenvironments is summarized, showing an overall change from tropical to sub-tropical gallery forest, forest fringe and woodland conditions in Member 4 to more open woodland and grassland habitats in the later units, but with suggestions of a wet localized topography in the Paranthropus -bearing Oldowan Infill.     

甜荞FeFUL2基因的克隆与表达分析

为了探索甜荞FUL同源基因参与花与籽粒发育调控的分子机制,该文采用同源克隆的方法从甜荞(Fagopyrum esculentum)长花柱和长雄蕊突变体(lpls)中克隆到1个长837 bp的FeFUL2基因(GenBank登录号为MG779493.1),其包含长690 bp的完整开放阅读框,编码1个由229个氨基酸残基组成的MADS-box转录因子。通过对FeFUL2进行分子系统发生、同源蛋白比对与转录因子结构分析,结果显示FeFUL2与核心真双子叶植物AP1/FUL亚家族转录因子中的euFUL进化系聚于1个进化分支,属甜荞euFUL型MADS-box转录因子,且包含1个57个氨基酸残基长的高度保守的MADS结构域、1个69个氨基酸残基长的次级保守的K结构域,其C末端转录激活区在序列长度和氨基酸残基组成上与其他euFUL型转录因子差异较大,但仍含有2个euFUL型转录因子特有的保守基元:FUL motif和paleo AP1 motif。用qPCR检测基因表达的组织特异性显示:FeFUL2基因在甜荞lpls突变体的根、茎、叶、花被片、雄蕊、雌蕊和发育4 d的幼果中均有表达,但其在花被片中表达量极显著高于该基因在其他器官中的表达量(LSD,P0.01)。综合转录因子的结构与基因的表达模式推测,FeFUL2基因与其他euFUL型基因的功能可能存在一定差异,其在花发育过程中可能主要参与甜荞花被片的发育调控。     

四川卧龙国家级自然保护区马先蒿属一新种——熊猫马先蒿

熊猫马先蒿(Pedicularis pandania)是在四川卧龙国家级自然保护区发现的马先蒿属一新种。该新种属于互生叶类群,其基生叶成丛,花冠属于短管有喙型,且下唇将喙包裹住,花管在近萼端发生约180度的扭旋使得花冠下唇在侧上方,这一特征明显区别于其他国产马先蒿物种。分子系统发育分析结果表明,熊猫马先蒿是Clade 7 成员,虽然与火焰系、假欧氏系、喙齿系、拟蕨系和长喙系等成员构成姐妹关系,但熊猫马先蒿的花冠形态特征明显区别于近缘物种。