多子芋3个品种群球茎质量和数量的差异显著性及变异性比较

多子芋3个品种群在水旱生态环境中的栽培比较试验表明：（1）多子芋在旱生环境中的单株母芋质量、单株子芋质量、单株孙芋质量、单株子芋孙芋总质量、单个子芋平均质量、单个孙芋平均质量、单个子芋孙芋平均质量都显著地高于在水生环境中的相应值,而单株子芋数量、单株孙芋数量、单株子芋孙芋总数量、单个曾孙芋平均质量差异不显著,仅单株曾孙芋质量和单株曾孙芋数量表现为水生环境极显著地高干旱生环境。因此,多子芋以旱栽为宜。（2）在品种群间,单株球茎质量和单株球茎数量在旱生环境中的差异较小,而在水生环境中的差异较大。红紫柄品种群对水生环境的适应性最强,绿柄品种群的适应性最弱。无论是在水生环境还是在旱生环境,品种群间同级别单个球茎质量的差异都不显著。（3）品种群间单株球茎质量、单株球茎数量、品种群内单个球茎质量的变异系数在水旱生态环境中,一般都表现为曾孙芋＞孙芋＞子芋,水生环境＞旱生环境,单株球茎质量＞单株球茎数量。     

芋种质资源开花结实状况调查

对保存在国家种质武汉水生蔬菜资源圃中的芋属（Colocasia）种质资源的开花结实状况调查表明：（1）在自然条件下,所有滇南芋[Colocasia antiquorum (L.) Schott]（2n=2x）中的野芋[即原C. esculenta (L.) var. antiquorum]和花用芋（即原C. tonoimo Nakai）资源全部开花;芋[Colocasia esculenta (L.) Schott]开花状况表现为：魁芋（2n=2x）、多头芋（2n=3x）、魁子兼用芋（2n=3x）都不开花,国内多子芋中,紫柄多子芋（2n=3x）都不开花,乌绿柄多子芋（2n=3x）和绿柄多子芋（2n=3x）有部分品种开花,但开花的品种具有不确定性;来源于东南亚国家的多子芋中,绿柄多子芋（2n=3x）开花率高,花期长,另有1份紫柄多子芋（2n=3x）开花,与国内多子芋（2n=3x）差异较大。开花率表现为东南亚多子芋（2n=3x）等于或高于国内芋;国内芋中,二倍体大于三倍体。花期最长的是东南亚的绿柄多子芋（2n=3x）,国内芋中,二倍体的开花率大于三倍体,二倍体的花期长于三倍体。（2）乌绿柄多子芋和花用芋的芽色都为红色,属于短附属器,其余类型的芽色为白色,属于长附属器。（3）在自然条件下,仅有2份紫柄野芋种质结实,其它种质未见结实。（4）本文还对不同类型芋的始花期、末花期、花期、单株花序丛数、单个叶轴花序数、单株总花序数、佛焰苞管部长度、佛焰苞檐部长度、附属器长、雄花序长、中性花序长、雌花序长等进行了比较。     

206份芋种质资源品质性状分析

对206份芋种质资源品质性状进行了分析,结果表明:按球茎类型来分,干物质含量魁芋>多头芋>魁子兼用芋>多子芋。淀粉含量魁芋>魁子兼用芋>多头芋>多子芋,干物质和淀粉含量都以魁芋最高,分别为27.38%、20.21%,多子芋最低,分别为19.54%、13.35%。蛋白质含量多头芋>魁芋>多子芋>魁子兼用芋,以多头芋的含量最高为1.54%,其他类型相差不大。可溶性糖含量魁芋>魁子兼用芋>多子芋>多头芋,以魁芋的可溶性糖含量最高为1.21%,其他芋类型相差不大。按母芋芽色来分,多子芋中,干物质、淀粉和蛋白质含量红芽多子芋>白芽多子芋,可溶性糖含量白芽多子芋>红芽多子芋;多头芋中,干物质、淀粉、可溶性糖白芽多头芋>红芽多头芋,蛋白质含量红芽多头芋>白芽多头芋。在整个芋种质资源中,芋的干物质含量与淀粉含量(r=0.9583**)、干物质含量与蛋白质含量(r=0.5529**)、淀粉含量与蛋白质含量(r=0.5284**)呈极显著正相关,干物质含量与可溶性糖含量(r=-0.2934**)、淀粉含量与可溶性糖含量(r=-0.3391**)、蛋白质含量与可溶性糖含量(r=-0.4498**)均呈极显著负相关。此外本研究还按叶柄颜色类型对芋种质资源品质性状进行了分析。     

黄河三角洲3种生境下的芦苇形态差异及生理生态特征研究

为阐明3种自然生境下的芦苇适应环境策略,通过设置样地,研究水生、湿生、旱生生境下芦苇的形态性状及生理生态特征,结果表明：（1）芦苇的最高高度、平均高度、最高冠幅、平均冠幅和盖度以水生生境最大,湿生生境次之,旱生生境最小;多度值以旱生和水生生境条件下较大;在水生条件下,芦苇往往形成单优势种群。（2）3种生境中的芦苇横走茎主茎长度不同,随地下水位下降,各分支无性系分株数量、分株高度和叶片数增多,分株距离、分株直径和叶面积减小;随着水分限制的加强,芦苇的节数和根数量增多,节长和根长变短。（3）在旱生生境下,根部和叶部SOD、POD活性和根部CAT活性显著高于水生和湿生,叶部CAT活性旱生显著低于水生。3种生境叶部MDA含量表现为旱生 > 湿生 > 水生,湿生和旱生生境下,根部MDA含量明显高于水生。这些形态性状的差异及生理生态特征可以看作芦苇对3种生境的适应性表现。     

荒漠草原猪毛蒿种群繁殖特征的土壤驱动因子分析

繁殖是植物生命活动的重要环节, 了解植物的繁殖特征是解释植物生态适应性和制定有效管理措施的重要依据。该研究以荒漠草原猪毛蒿(Artemisia scoparia)种群为研究对象, 通过测定不同土壤类型的理化性质和猪毛蒿的繁殖特征, 以期探讨影响其繁殖特征的主要土壤驱动因子。结果表明: 灰钙土、风沙土和基岩风化残积土的水溶性碳含量、全氮含量、全磷含量、全盐含量、土壤水分含量、土壤硬度存在显著差异。猪毛蒿平均个体大小、单株头状花序的平均质量和数量均以灰钙土生境下最大, 基岩风化残积土最小。繁殖分配在不同土壤类型下无显著差异, 但与单个头状花序质量、单株头状花序数量和质量间呈极显著正相关关系。单株头状花序数量与单个头状花序质量间呈负相关关系。在风沙土生境下, 单株头状花序质量主要受到土壤水溶性碳含量、土壤水分含量以及pH值的共同影响; 单株头状花序数量受全盐含量的影响最大; 繁殖分配和单个头状花序质量主要受全碳含量的影响。灰钙土生境下, 单株头状花序质量与土壤水溶性碳含量、土壤水分含量和有机碳含量呈正相关关系; 速效氮含量显著影响着单株头状花序数量。而基岩风化残积土生境下, 繁殖特征的变异主要受到土壤水溶性碳含量、土壤硬度、土壤水分含量、全磷和速效磷含量的影响。综合分析发现, 土壤因子对猪毛蒿繁殖特征的影响程度不同, 其中单株头状花序数量和质量极显著地受到土壤水溶性碳含量和土壤水分含量的影响, 繁殖分配和单个头状花序质量与土壤水溶性碳含量、土壤水分含量呈负相关关系。因此, 土壤水溶性碳含量和土壤水分是荒漠草原地区影响猪毛蒿种群繁殖特征的主要土壤因子。     

喜旱莲子草对喀斯特三种不同生境的可塑性反应

喜旱莲子草自入侵以来在我国各地广为传播蔓延,对人们生产生活产生了重要影响。该研究通过野外采样和室内理化指标分析,探讨喀斯特不同生境中喜旱莲子草的可塑性。结果表明:(1)在三种生境中喜旱莲子草的节间长度、叶面积、单株重和叶干重差异显著。(2)在岩石环境中其无性繁殖器官——茎的投入比例占其生物量的比例最大,其次是行道生境和湘江河道。(3)节间距随环境因子从岩石环境、绿化行道和水生生境的变化,依次增加,叶质比(叶面积/质量)也随水分环境的增加而增加;(4)在岩石环境中,喜旱莲子草通过缩短节间距并增加无性繁殖器官——茎的质量来增加其在水分匮乏生境的繁殖能力。该研究结果为喜旱莲子草今后的防治对策提供了科学依据。     

喜旱莲子草叶片、细根功能性状对异质生境的响应

叶片、细根功能性状对植物的入侵过程具有重要影响,探究植物叶片、细根功能性状间的差异和联系,阐明植物地上地下部分对异质生境的响应,对于理解生物入侵机制具有重要意义。以3种生境(旱生、湿生、水生)的喜旱莲子草(Alternanthera philoxeroides)为研究对象,应用野外调查的方法,测定其叶片、细根共20个功能性状指标,分析其在不同生境中的差异性及其相关性。结果表明：(1)3种生境下植物功能性状具有显著差异(P<0.05),其中旱生生境的叶鲜质量((1.12±0.14) g)、叶面积((4.80±0.57) cm²)、叶体积((1.12±0.16) cm³)最大;水生的叶长宽比(2.95±0.22)、根组织密度((4.14±0.52) g·cm^-3)最大。(2)湿生叶片相对含水量变异系数最大(0.603),叶长宽比变异系数最小(0.057);旱生根分支数变异系数最大(0.453),水生根平均直径变异系数最小(0.065)。(3)叶片性状之间、细根性状之间联系密切,根-叶性状间的联系较少。(4)旱生偏向于获...     

松嫩平原羊草种群营养繁殖的季节动态及其生物量与密度关系的分析

本文根据野外定位定期观测,分析了羊草[Aneurolepidium chinense(Trin.)Kitag.]种群和羊草个体群营养繁殖的特点。结果表明,在整个生长季,羊草能不断地进行营养繁殖。在移植当年,羊草分蘖株个体群的营养繁殖潜力比实生苗个体群的更大,两个实验个体群的数量均符合于逻辑斯谛曲线增长。生殖生长对羊草的营养繁殖有较大的影响。天然割草场上的羊草种群在生物量达最高时期,种群植株的大小受密度的制约,平均单株重量与密度之间遵循-0.6699 幂的规律性变化。综合分析表明,在松嫩平原天然割草场上,羊草种群依靠营养繁殖更新延续、自我调节,但该种群尚未达到环境所能容纳的最大数量。     

卧龙亚高山暗针叶林不同林冠环境下华西箭竹分株种群结构特征

详细调查了林下、中林窗、大林窗和林缘旷地等4种亚高山暗针叶林林冠环境下的华西箭竹（Fargesia nitida）分株种群,对其表现结构（株高、基径和生物量）和年龄结构进行了较系统的对比研究.主要研究结果如下：（1）分株水平上,华西箭竹表现结构在4种林冠环境下均有极显著差异（p＜0.01）,且随林冠郁闭度的减小,分株个体的高度、基径和生物量有递增的趋势（林下＜中林窗＜大林窗）;（2）分株各构件在总生物量中所占比例随林冠环境变化而改变：除林缘旷地外,叶的生物量百分比与林冠郁闭度呈正相关.林缘旷地中,地下茎和根系的生物量百分比均高于其余3种环境;（3）不同林冠环境下分株单位叶面积叶重存在显著差异（p＜0.05）,且随林冠郁闭度的减小而增大.单叶生物量和单叶面积均以中林窗最大,林缘旷地次之,二者与大林窗或林下均有显著差异（p＜0.05）.华西箭竹的单株叶片数量以大林窗最大,与其余3种环境有极显著差异（p＜0.01）;（4）分株种群的死亡率以林下最低（P＜0.01）,但各种群平均年龄间无显著差异（p＞0.05）.可见,华西箭竹分株种群对林冠环境变化的反应主要体现在形态和生物量分配上,而非种群的年龄上.     

贵州雷公山秃杉林不同林冠环境下箭竹分株种群结构特征

通过对贵州雷公山秃杉林的4种林冠环境,即林下(FU)、中林窗(MG)、大林窗(LG)和林缘旷地(FEW)内的箭竹的分株种群结构（包括株高、基径、生物量、叶和分株数等）和年龄结构进行较系统对比研究。结果显示:（1)从林下→中林窗→大林窗,箭竹分株种群的株高(h)、基径（bd)与生物量显著增加。（2)在4种林窗环境中,箭竹各构件的生物量的百分比发生相应变化,枝和叶片生物量的百分比沿林下→中林窗→大林窗→林缘旷地的顺序显著减小,在林缘旷地,地下茎、粗根（d＞0.5 mm)和细根（d≤0.5 mm)生物量的百分比显著高于其他3种林冠环境。（3)箭竹分株单位叶面积叶重沿林下→中林窗→大林窗→林缘旷地的顺序显著增大,单叶生物量与叶面积以中林窗最大,林缘旷地次之,二者与大林窗或林下差异显著;大林窗的单株叶片数显著高于其余3种林冠环境。（4)在4种林冠环境中,箭竹分株种群死亡率以林下最低,但各种群平均年龄间无显著差异。研究表明,箭竹分株种群对林冠环境变化的响应主要体现在形态与生物量的分配上,而非种群的年龄。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain.

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.     

Identification and composition of the tonsillar and anal enterococcal and streptococcal flora of dogs and cats

Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent. hirae was found almost as often as Ent. faecalis. Most Ent.faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol. Typical Ent. avium as well as atypical Ent. avium -like strains were seen in dogs, while the related species Ent. raffinosus was associated with cat tonsils. Enterococcus cecorum also occurred mainly in cats. Certain atypical strains, presumptively identified as Ent. cecorum , shared characteristics with Ent. columbae.
The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep. canis. Streptococcus canis and Strep. bovis predominated in anal swabs. The canine Strep. suis differed from the common porcine strains in fermenting mannitol.
Forty-seven of the 288 isolates examined could not be identified or related to known species. The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described.     

Molecular characterisation of species and genotypes of Cryptosporidium and Giardia and assessment of zoonotic transmission

The molecular characterisation of species and genotypes of Cryptosporidium and Giardia is essential for accurately identifying organisms and assessing zoonotic transmission. Results of recent molecular epidemiological studies strongly suggest that zoonotic transmission plays an important role in cryptosporidiosis epidemiology. In such cases the most prevalent zoonotic species is Cryptosporidium parvum. Genotyping and subtyping data suggest that zoonotic transmission is not as prevalent in the epidemiology of giardiasis. Molecular characterisation of Cryptosporidium and Giardia is a relatively recent application that is evolving as new genes are found that increase the accuracy of identification while discovering a greater diversity of species and yet unnamed taxa within these two important genera. As molecular data accumulate, our understanding of the role of zoonotic transmission in epidemiology and clinical manifestations is becoming clearer.     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000