福州鼓山季风常绿阔叶林及其林缘几种植物叶热值和营养成分

研究了福州鼓山次生的南亚热带季风常绿阔叶要及其林缘不同层次１３种植物叶热值、灰分含是及营养成分。结果表明：群落的不同层次平均灰分含量从低到高依次是乔木层（６．８％）,草本层（８．５％）、灌木层（１０％）;平均含灰分热值（ＧＣＶ）从低到高低次是草本层（１６．８９ＫＪ／ｇ）、灌木层（１７．７５ＫＪ／ｇ）、乔木层（１９．７９ＫＪ／ｇ）;平均不含灰分热值（ＡＦＣＶ）从低到高依次是草本层（１８．５５ＫＪ／ｇ     

新疆呼图壁绿洲外缘的盐节木（Halocnemum strobilaceum）及其群落的生物生态学特征

盐节木株丛矮小,高约２０－４０ｃｍ;５月底至８月底净生长高度约３ｃｍ。侧根发达,主要分布在土壤由表层往下水分含量急增、多数情况下盐分逐步降低的２０－４０ｃｍ的土层内,几乎与地表平行伸展,有的长达３ｍ以上。盐节木群落为多汁盐柴类半灌木荒漠中的一个群系。本区记载有８个群丛,分布在地下水位１．０－１．７ｍ、表土层含盐量为４％－８％的盐土上。种类组成贫乏,群落结构简单,总覆盖度３０％－５０％,生物量１０００－２０００ｋｇ／ｈｍ￣２。群落中盐节木、有叶盐爪爪（Ｋａｌｉｄｉｕｍｆｏｌｉａｔｕｍ）具有很高的Ｎａ、Ｓ含量,分别在５００００ｍｇ／ｋｇ、１００００ｍｇ／ｋｇ以上;Ｎａ／Ｋ、Ｎａ／Ｃａ、Ｓ／Ｐ比值为８．５－２６．０,其它植物为１左右;植物中的Ｃａ／Ｍｇ比值为１．０－１．６。盐节木６种元素含量的季节变化,Ｎａ呈增高趋势;其变化曲线与Ｃａ、Ｍｇ相反;Ｎａ、Ｓ曲线相似。盐节木水提取液中具有高的Ｃｌ￣－、含量,ｐＨ为６．６６－６．８４。盐节木群落广泛分布在绿洲外缘的盐碱地上。在盐碱地改良、防止风沙、保护绿洲、牲畜冬春放牧等方面,具有重要的生态经济意义。     

乌龟胚胎及仔龟的卵黄代谢

乌龟卵、卵黄、剩余卵黄和仔龟的含水量分别为６８．８７％、６１．４７％、６０．７５％和７６．４３％;干重分别为２．２９１５±０．２１０１ｇ,１．３０７１±０．２９１３ｇ,０．２６８１±０．０２４１ｇ和１．２３０５±０．２９９４ｇ;脂肪含量分别为１８．０３％、３１．７６％、３２．１０％和１９．３０％。卵黄、剩余卵黄和仔龟的热值分别为６．７１ｋｃａｌ／ｇＤＭ,６．７６ｋｃａｌ／ｇＤＭ和４．１０ｋｃａｌ／     

鼎湖山植物群落及其主要植物的热值研究

在测定了南亚热带鼎湖山的４种植物群落３７种主要植物热值的基础上得知：所有这些植物各器官的干重热值和去灰分热值分布范围为：叶片１７２４２．７～２４５３３．３Ｊ·ｇ－１和１８１８８．５～２５８７９．０Ｊ·ｇ－１;根１４９２７．１～１９２８７．８Ｊ·ｇ－１和１５６２０．７～２０３４５．８Ｊ·ｇ－１,枝、干１６１５８．１～２１８１５．９Ｊ·ｇ－１和１６９０８．９～２３０１２．６Ｊ·ｇ－１。呈现叶＞枝或干＞根,地上部分＞地下部分的格局;同一群落从乔木层到草本层,各层次的叶片和平均干重热值是逐渐减小的,且上层乔木单位面积叶片含能量高于下层灌木的,这种格局可能与群落内光照强度的递减有关;同一种植物在演替早期各群落内的热值差距大,而在演替后期各群落内的热值差距小得多,这意味着随群落演替的进行,生境趋同性增大,因而热值接近;各群落内叶片的热值最高,凋落叶的次之,地被物的最小,影响凋落叶释放能量的主要因素不是微生物数量的大小,而可能是温度、淋溶和水分等生态因子。     

儿茶酚胺类药物对草鱼生长激素分泌的影响

本文研究了儿茶酚胺类药物对草鱼生长激素水平的影响。腹腔注射儿茶酚胺合成抑制剂α－甲基－对－酪氨酸（α－ＭＰＴ,５μｇ／ｇｂ·ｗ和５０μｇ／ｇｂ·ｗ）显著降低草鱼鱼种血清生长激素水平,腹腔注射儿茶酚胺能神经毒素６－羟多巴胺（６－ＨＯＤＡ,５μｇ／ｇｂ·ｗ和５０μｇ／ｇｂ·ｗ）也显著降低草鱼鱼种血清生长激素水平。阿卟吗啡（ＡＰＯ,７．１ｍｇ／Ｋｇｂ·ｗ和１２．５ｍｇ／Ｋｇｂ·ｗ）通过背大动脉插管注入草     

闽南毛竹林几种元素的累积和分配

研究了闽南毛竹群落中几种常量元素的累积情况,结果表明,在整个毛竹群落现存量中Ｎ、Ｐ、Ｓｉ、Ｋ、Ｃａ和Ｍｇ总累积量分别为１３．９６、２．８９、７０．０４、４１．２９、５．８４和３．６３ｇ·ｍ－２．在毛竹的各组分中,竹叶中的各种元素含量均最高,竹鞭中元素含量也较多．６种元素中,Ｓｉ的浓度最高,平均为１．６０％,Ｋ次之,平均为０．５５％．Ｓｉ在叶中含量最高,达１５．６０ｇ·ｍ－２,Ｎ和Ｋ在竹杆中含量最高,分别为６．５８和２０．６７９·ｍ－２．林下植物根中Ｓｉ含量也高达１１．４５ｇ·ｍ－２．竹叶中Ｓｉ含量很高还表明了它是从叶中含Ｓｉ量低的木本植物向合Ｓｉ量高的禾草进化的过渡类型．     

红树植物秋茄落叶分解碎屑的有效能研究

测定了福建红树植物秋茄各季节落叶分解碎屑中水解有效能（ＨＡＣ）、无丹宁水解有效能（ＴＦＨＡＣ）和化学有效能（ＣＡＣ）的绝对含量和相对含量。测定结果表明：落叶中有效能的绝对含量和它占总能量的百分含量的季均值是：ＨＡＣ４．０６ｋＪ／ｇＤＷ,２０．８５％;ＴＦＨＡＣ３．３２ｋＪ／ｇＤＷ,１６．６８％。在半分解（失重率为５０％）的碎屑中它们降为ＨＡＣ１．７５ｋＪ／ｇＤＷ,９．２５％ ;ＴＦＨＡＣ１．６４ｋ     

秋茄红树植物落叶分解的碎屑能量研究

测定了红树植物秋茄（Ｋａｎｄｅｌｉａ ｃａｎｄｅｌ （Ｌ．） Ｄｒｕｃｅ）落叶在不同季节分解过程中碎屑的热值和富能有机化合物的变化。结果表明,季节间落叶的热值差别不大,平均为１９．６３ ｋＪ／ｇ干重或２１．５５ ｋＪ／ｇ 去灰分干重。各季节的落叶在其分解后的碎屑的热值均明显提高,且夏秋季快于冬春季,但它们与分解程度有相应的相关关系：分解初期上升,后期稍降,最大值出现在半分解期（失重５０％ ）附近。碎屑的最大热值平均比落叶的热值提高１７．６７％ （干重热值）或１４．３５％ （失灰分干重热值）。分解中总能量的耗散稍慢于干物质的损失。随分解的进行,碎屑中粗蛋白、粗脂肪、粗纤维的能量增大,而无氮浸出物的能量减少。     

盐或低温胁迫对花生幼苗下胚轴ATP酶和质膜中PIP2含量的影响

经６％－１２％Ｄｅｘｔｒａｎ Ｔ７０密度梯度离心,获得了纯度较高的７ｄ龄花生幼苗下胚轴质膜和液泡膜制剂。１５０ｍｍｏｌ／Ｌ ＮａＣｌ或１０℃低温处理花生幼苗２４ｈ,其下胚轴质膜上的Ｍｇ＾２＋激活的ＡＴＰａｓｅ活性分别提高了３７．６％和１７．２％;Ｃａ＾２＋－ＡＴＰａｓｅ活性分别提高４５．８％和３３．６％。上述盐或低温处理也提高了液泡膜上Ｍｇ＾２＋激活的ＡＴＰａｓｅ活性,分别为对照的１４１．２％和１     

新疆呼图壁绿洲外缘的琵琶柴生物生态学特性研究

琵琶柴（Ｒｅａｕｍｕｒｉａｓｏｏｎｇｏｒｉｃａ）为半灌木,株丛高平均为２４．３ｃｍ,冠幅和高与地上生物量的复相关系数为０．９２１,在０．００１水平上相关。主根随株龄的增加不断胀裂,下端逐渐枯萎、腐烂。侧根发达,几乎与地面平行伸展,长达１～２ｍ,有的在２ｍ以上。本区记载有９个琵琶柴群丛,群落种类组成贫乏,分布稀疏,结构简单;总覆盖度一般为１０％～１５％,有的达到３０％;生物量低。植株不同部位元素含量差异较大,叶中的Ｋ、Ｎａ、Ｃａ、Ｍｇ含量较高,老枝中的Ｆｅ、Ａｌ含量较高,而Ｃｕ、Ｚｎ在根中含量最高;不同地点的琵琶柴叶中Ｂａ的含量变化较大,变异系数为１０９．７８％。元素含量的季节变化,Ｐ、Ｓ、Ｋ呈下降趋势;Ｎａ、Ｃａ、Ｍｇ的季节变化随部位的不同而有所差异。琵琶柴叶中全盐量平均为２７．９１％,具有较高的Ｃｌ－和ＳＯ２－４含量;脯氨酸含量高达０．３２％;ｐＨ值为６．０４～７．０９。琵琶柴群落广泛分布于绿洲外缘的盐渍土和盐化灰漠土上,对荒漠的生态保护,防风固沙,牲畜冬春放牧等方面具有重要的生态经济意义。     

Pre-exposure to UV irradiation increases the transfer frequency of the IncJ conjugative transposon-like elements R391, R392, R705, R706, R997 and pMERPH and is recA+ dependent

The enteric conjugative transposon-like IncJ elements R391, R392, R705, R706 and pMERPH, all demonstrated increased conjugative transfer upon UV irradiation. The transfer frequency increased on average from its basal rate of 10(-5) to 10(-3) per recipient, upon pre-exposure to UV irradiation. However, the transfer frequency of R997, which was higher than the other IncJ elements at 10(-3) per donor, showed a smaller increase. This effect was shown to be recA+ dependent in all cases. Using PCR primers directed outwards from the ends of the integrated R391 element it was observed that a circular intermediate of the element forms within the host, which has been proposed to be a transfer intermediate. Using real-time PCR, it was determined that the amount of the circular intermediate produced increased substantially upon UV irradiation.     

大黄属3种大黄植物不同部分蒽醌含量的测定与比较

采用C18反相柱高效液相色谱方法分离、外标法定量对大黄属掌叶组唐古特大黄、波叶组波叶大黄、穗序组穗序大黄的根（及根茎）、叶片、叶柄、主茎四部分的芦荟大黄素、大黄酸、大黄素、大黄酚4种游离和结合蒽醌的含量进行了测定和比较。结果表明：唐古特大黄中,叶片中的游离蒽醌含量高于其它部分,游离蒽醌总量地上部分远高于地下部分;结合蒽醌则根中最高,蒽醌总量地下部分远高于地上部分。波叶大黄和穗序大黄中,游离和结合蒽醌均为根中最高,穗序大黄蒽醌总量地下部分远高于地上部分,而波叶大黄中,游离蒽醌总量地上部分高于地下部分,结合蒽醌总量地上部分与地下部分相差不大,地上部分略高于地下部分。     

Identification and Characterization of a Mycobacterial (2R,3R)-2,3-Butanediol Dehydrogenase

Bacterial strain B-009, capable of using racemic 1,2-propanediol (PD), was identified as a rapid-growing member of the genus Mycobacterium. The strain is phylogenetically related to M. gilvum, but has slightly different physiological characteristics. An NAD⁺-dependent enantioselective alcohol dehydrogenase, which acts on R-PD, was purified from the strain. The enzyme was a homodimer of a peptide coded by a 1047-bp gene (mbd1). A highly conserved sequence for medium-chain dehydrogenase/reductases with a preference for secondary alcohols was found in the gene. Hydroxyacetone was produced from R-PD by an enzymatic reaction, indicating that position 2 of the substrate was oxidized. The enzyme activity was highest for (2R,3R)-2,3-butanediol (R,R-BD), enabling the enzyme to be identified as (2R,3R)-2,3-butanediol dehydrogenase (R,R-BD-DH). A homology search revealed M. gilvum, M. vanbaalenii, and M. semegmatis to have ORFs similar to mbd1, suggesting the widespread distribution of genes encoding R,R-BD-DH among mycobacterial strains.     

Identification of components of a new stability system of plasmid R1, ParD, that is close to the origin of replication of this plasmid

Summary We provide evidence that a mutation which derepresses an autoregulated system that is located in the vicinity of the basic replicon of R1, stabilizes the ParA^- and ParB^- miniplasmid of R1 pKN1562, without increasing its copy number. The system, which we have called ParD, maps inside the 1.45-kb PstI-EcoRI fragment that is adjacent to the origin of replication of the plasmid. Two protiens whose expression is coordinated are components of the system. The sequence of the PstI-EcoRI fragment was obtained. The wild-type ParD system determines in cis a basal but detectable stability.     

黄芩甙对痢疾杆菌R质粒体外消除作用的实验研究

以携带R质粒的痢疾杆菌F_(13)株为靶细菌,以黄芩甙作为R质粒消除剂,进行R质粒体外消除试验。实验组R质粒的消除率为0.3%,对照组中SDS的消除率为0.6%,吖啶橙的消除率0.42%。琼脂糖凝胶电泳结果显示,消除子都丢失了相应的质粒带。     

H-FABP、MC4R、ADD1基因多态性在3个猪群中分布及其与肌内脂肪和背膘的相关研究

具有不同遗传特性的猪种具有不同的肉质性状。尤其是地方品种和引进品种间在肉质性状存在极大的差异。在已有的研究中H-FABP,MC4R,ADD1基因同肌内脂肪或背膘相关。利用梅山猪、苏太猪和杜×长×大猪为试验动物,研究上述3个基因的多态性分布和多态性同肌内脂肪和背膘的相关性。结果表明：3个基因的多态性分布在不同猪种间存在极显著的差异,这种差异可能是肌内脂肪（IMF）或背膘（BF）不同的主要原因之一。连锁分析表明：H-FABP和ADD1基因多态性同IMF有显著的相关,但是同BF没有显著的相关;MC4R基因的多态性同IMF和BF都有显著相关性。说明：H-FABP和ADD1基因多态性有可能应用到提高IMF,同时不影响BF的育种实践中。      

Isozyme variability and differentiation between Rhodnius prolixus, R.robustus and R.pictipes, vectors of Chagas disease in Venezuela

Enzyme polymorphism in triatomine bugs of the genus Rhodnius (Hemiptera: Reduviidae), vectors of Chagas disease, is analysed using both starch and polyacrylamide gel electrophoresis. Out of forty-five enzymes assayed, the electromorphs of seventeen of them: AO, CA, DIA, ES, ES-A, FH, GPD, G6PD, GPI, MDH, ME, 6PGD, PGM, ACON, ACPH, LAP and SOD, involving twenty-two putative structural loci, were scorable. These gene-enzyme systems were therefore selected for routine characterization of R.prolixus Stal adults from different strains. The first thirteen enzymes, involving sixteen structural loci, were also analysed in first instar nymphs of the three species, R.prolixus, R.robustus Larrousse and R.pictipes Stal. Allelic frequencies were calculated for three R.prolixus strains: three to five loci appeared to be polymorphic. The proportion of polymorphic loci (22%) and the average heterozygosity (0.06) indicated low genetic variability, with significant differences between the strains at individual loci. Rhodnius prolixus and R.robustus were found to have identical isozymic patterns. R.pictipes was genetically well differentiated, with twelve diagnostic loci.     

A Putative Calcium-Permeable Cyclic Nucleotide-Gated Channel, CNGC18, Regulates Polarized Pollen Tube Growth

A tip-focused Ca^2＋ gradient is tightly coupled to polarized pollen tube growth, and tip-localized influxes of extracellular Ca^2＋ are required for this process. However the molecular identity and regulation of the potential Ca^2＋ channels remains elusive. The present study has implicated CNGC18 （cyclic nucleotide-gated channel 18） in polarized pollen tube growth, because its overexpression induced wider and shorter pollen tubes. Moreover, CNGC18 overexpression induced depolarization of pollen tube growth was suppressed by lower extracellular calcium （[Ca^2＋]ex）. CNGC18-yellow fluorescence protein （YFP） was preferentially localized to the apparent post-Golgi vesicles and the plasma membrane （PM） in the apex of pollen tubes. The PM localization was affected by tip-localized ROP1 signaling. Expression of wild type ROP1 or an active form of ROP1 enhanced CNGC18-YFP localization to the apical region of the PM, whereas expression of RopGAP1 （a ROP1 deactivator） blocked the PM localization. These results support a role for PM-Iocalized CNGC18 in the regulation of polarized pollen tube growth through its potential function in the modulation of calcium influxes.