密粘褶菌松木粉培养物对黑翅土白蚁的生物活性

【目的】研究密粘褶菌Gloeophyllum trabeum(Pers.:Fr.)Murr松木粉培养物对黑翅土白蚁Odontotermes formosanus(Shiraki)的生物活性。【方法】比较了密粘褶菌松木粉培养物不同溶剂提取液对采食工蚁的踪迹和引诱活性,研究不同浓度正己烷和乙酸乙酯提取液的引诱活性变化。【结果】正己烷提取液表现出高引诱活性和踪迹活性,乙酸乙酯、三氯甲烷、丙酮提取液具有高引诱活性和较低踪迹活性,甲醇、乙醇提取液表现出较高踪迹活性和较低引诱活性。正己烷提取液浓度与趋性反应率的回归方程为y=12.561ln(x)+50.11;乙酸乙酯提取液浓度与趋性反应率的回归方程为y=12.161ln(x)+51.411。【结论】密粘褶菌松木粉培养物对黑翅土白蚁采食工蚁具有明显的踪迹和引诱活性。正己烷和甲醇提取液的踪迹活性最强,乙酸乙酯和正己烷提取液的引诱活性最强。正己烷和乙酸乙酯提取液对采食工蚁的引诱活性具有很好的浓度相关性。     

白蚁防治中引诱技术的应用

白蚁是一类危害面广、破坏性极大的世界性害虫。利用各种防治技术控制白蚁危害由来已久,引诱技术乃其中一种。采用引诱技术具有防治成本低、针对性强、效果显著、对生态环境破坏性小等优点。白蚁是社会性昆虫,其行为有利于我们采用引诱技术实施防治。引诱技术包括饵诱法、信息素引诱法、灯诱法等具体方法,本文主要介绍饵诱法和信息素引诱法应用情况及研究进展。１饵诱法食物引诱是最古老、最简单易行的引诱方法。其采用３种方式：（１）诱集．杀灭：在白蚁活动区域设置白蚁喜食饵料（堆、坑）诱其前来取食,然后用烫、烧、踩、喂鸡和药杀…     

褐腐真菌产生的羟基自由基HO˙对纤维素作用的研究

由褐腐真菌的典型菌株——密粘褶菌Gloeophyllum trabeum的胞外培养液中分离纯化得到一能还原Fe3 ,产生羟基自由基HO˙的多肽组分(称作Gt因子)。 采用HO˙特异性的抑制剂硫脲,对Gt因子产生的HO˙在纤维素降解中的作用进行了对照研究,结果表明Gt因子及其产生的HO˙在纤维素降解中起着重要的作用,为褐腐菌HO˙氧化降解纤维素机制假说的确立提供了一些依据。     

褐腐真菌产生的羟基自由基HO˙对纤维素作用的研究*

由褐腐真菌的典型菌株——密粘褶菌Gloeophyllum trabeum的胞外培养液中分离纯化得到一能还原Fe3+,产生羟基自由基HO˙的多肽组分(称作Gt因子)。 采用HO˙特异性的抑制剂硫脲,对Gt因子产生的HO˙在纤维素降解中的作用进行了对照研究,结果表明Gt因子及其产生的HO˙在纤维素降解中起着重要的作用,为褐腐菌HO˙氧化降解纤维素机制假说的确立提供了一些依据。     

几种饵料对红火蚁觅食的引诱作用

在荒地类型生境中测定花生酱、猫饲料、狗饲料、花生油、面包及蜂蜜等几种常见饵料对红火蚁的引诱作用。结果表明:面包、狗饲料、猫饲料和花生酱对红火蚁引诱力较强,花生油次之,蜂蜜最低;选择性试验结果表明红火蚁对供试的几种饵料无明显选择性。     

加拿大杨树叶气味对棉铃虫的引诱作用

加拿大杨树枝把田间诱蛾试验,单把日平均诱蛾4.17头,雌性比为1.72;在加拿大杨树枝把中加入棉铃虫性诱剂诱芯后,单把日平均诱蛾5.5头,雌性比为1.86.鲜加拿大杨树叶粗提物对棉铃虫刚羽化处女雌蛾引诱效果为26.67%;经过堆放2天的杨树叶粗提物对棉铃虫刚羽化的处女雌蛾引诱效果为44.44%.     

杨扇舟蛾性引诱行为的观察

杨扇舟蛾羽化高峰在19～21时,羽化后4小时左右性成熟,雌蛾分泌性外激素,对雄蛾产生性引诱;以羽化当日性引诱力最强;这种性行为直至交配或死亡为止。活雌蛾性外激素粗提液对雄蛾也有引诱力,但诱雄蛾效果不如活雌蛾。     

茶蚜体表漂洗物对天敌的引诱活性及组分分析

行为生测和触角电位反应都证明茶蚜Toxoptera aurantii体表的正己烷或乙醚漂洗物对茶蚜重要天敌中华草蛉Chysopa sinica、蚜茧蜂Aphidius sp.和七星瓢虫Coccinella septempunctata具有显著的引诱效应,正己烷漂洗物的活性稍强。GC、GC-MS分析表明正己烷漂洗物中主要组分是苯甲醛、十一烷、2, 5-己二酮、2,5-二氢噻吩、芳樟醇、萘、4-甲基-辛烷、1, 2-苯甲酸-双-（二丁基-邻苯二甲酸甲酯）、二丁基-邻苯二甲酸甲酯和二十烷,其中苯甲醛、2, 5-己二酮和芳樟醇含量稍大。乙醚漂洗物中主要组分为反-2-己烯酸、正十七烷、2,6,10,14-四甲基十五烷、二十烷、四甲基四十烷、二丁基-邻苯二甲酸酯和十九烷,前2种组分含量较大。     

挥发性化合物对枯叶蛱蝶觅食的引诱作用

【目的】鉴于枯叶蛱蝶Kallima inachus(Boisduval)在觅食过程中以嗅觉信息为主导,本研究试图找出吸引枯叶蛱蝶觅食的关键化合物。【方法】本文利用顶空抽样法收集了西瓜、柿子、香蕉、苹果、橙和梨6种半腐烂水果的挥发物,并用GC/MS测定了其成分。然后从中筛选出5种挥发物以及前人报道的存在于腐烂发酵物中的乙醇和乙酸,通过田间行为观察研究了枯叶蛱蝶对这些挥发物分别与乙醇和去离子水对比的引诱效果。【结果】在0.5%浓度下,供试挥发物都对枯叶蛱蝶觅食有一定的引诱作用,其中,乙酸乙酯、丁酮和α-蒎烯引诱效果与乙醇无显著差异(P>0.05),且均显著高于去离子水(P<0.05);异戊醇、乙酸和乙酸异戊酯的引诱效果均显著低于乙醇(P<0.05),略高于去离子水但均差异不显著(P>0.05);乙醇的引诱次数高于丁酮、α-蒎烯、异戊醇、乙酸和乙酸异戊酯。【结论】乙醇是枯叶蛱蝶觅食的关键化合物;枯叶蛱蝶在觅食过程中可利用多种气味信息。结果可为今后制定枯叶蛱蝶保护措施提供依据。     

白蚁菌圃中木质素降解菌的筛选及降解效果

为了选出能够有效降解木质素的菌株,以废弃的白蚁巢为来源进行筛选,并以无氮培养基、碱木质素培养基、苯胺蓝培养基和愈创木酚培养基进行复筛.对筛选出的菌株进行16SrRNA鉴定以及形态学分析.通过扫描电镜、傅里叶红外光谱对降解前后的碱木质素进行降解特性的解析.结果筛选出一株具有木质素降解能力的细菌经鉴定并命名为R.ornit...     

苹果渣发酵生产饲料蛋白的菌种筛选

通过对初选的１００株菌种进行筛选,选到了适合苹果渣发酵的菌种,在此基础上进行双菌种混生发酵,获得了优良的菌种组合。采用所选菌种组合在通过试验所确定的配方和试验条件下进行了发酵,所得产物的粗蛋白含量达到２９.３０％,提高４５.７７％,蛋白质含量达到２７．５６％,提高８２．８８％,粗纤维降低幅度为２３．２７％。试验结果还表明,所选菌种组合有降低棉籽饼中棉酚含量的作用,降低幅度超过９０％。     

SOME EFFECTS OF HOST NUTRITION ON THE SUSCEPTIBILITY OF PLANTS TO INFECTION BY CERTAIN VIRUSES

Fertilizer treatments that greatly influenced the growth of tobacco and potato plants in pots had little effect on the number that became infected with potato virus Y when the plants were colonized by equal numbers of infective aphids, though the number was slightly decreased by nitrogen and increased by phosphorus.
The number of local lesions produced on leaves of tobacco and Nicotiana glutinosa by tomato aucuba mosaic and tobacco mosaic viruses was increased by additions of both nitrogen and phosphorus, provided that these also increased growth. The predominant effect of both nutrients in increasing susceptibility was indirect by increasing plant size, but over certain critical ranges both elements also increased the numbers of lesions produced per unit leaf area. Conditions of maximum susceptibility approximated closely to those producing optimal growth, and susceptibility, whether measured by lesions per half-leaf or per unit area, was decreased by a deficiency or excess of either element. Sometimes the addition of nitrogen reduced susceptibility when still increasing plant growth.     

HOW TO COMPENSATE FOR COSTLY SEXUALLY SELECTED TAILS: THE ORIGIN OF SEXUALLY DIMORPHIC WINGS IN LONG-TAILED BIRDS

Recent work on birds suggests that certain morphological differences between the sexes may have evolved as an indirect consequence of sexual selection because they offset the cost of bearing extravagant ornaments used for fighting or mate attraction. For example, long-tailed male sunbirds and widowbirds also have longer wings than females, perhaps to compensate for the aerodynamic costs of tail elaboration. We used comparative data from 57 species to investigate whether this link between sexual dimorphism in wing and tail length is widespread among long-tailed birds. We found that within long-tailed families, variation in the extent of tail dimorphism was associated with corresponding variation in wing dimorphism. One nonfunctional explanation of this result is simply that the growth of wings and tails is controlled by a common developmental mechanism, such that long-tailed individuals inevitably grow long wings as well. However, this hypothesis cannot account for a second pattern in our data set: as predicted by aerodynamic theory, we found that, comparing across long-tailed families, sexual dimorphism in wing length varied with tail shape as well as with sex differences in tail length. Thus, wing dimorphism was generally greater in species with aerodynamically costly graduated tails than in birds with cheaper, streamer-shaped tails. This result was not caused by confounding phylogenetic effects, because it persisted when phylogeny was controlled for, using an independent comparisons method. Our findings therefore confirm that certain aspects of sexual dimorphism may sometimes have evolved through selection for traits that reduce the costs of elaborate sexually selected characters. We suggest that future work aimed at understanding sexual selection by investigating patterns of sexual dimorphism should attempt to differentiate between the direct and indirect consequences of sexual selection.     

吗啡受体拮抗剂翻转电针镇痛的程度决定于电针刺激的频率

电针镇痛能被吗啡受体拮抗剂所对抗,被认为是内源性吗啡样物质参与针刺镇痛的有力证据。给大鼠皮下注射吗啡受体拮抗剂纳洛酮或纳曲酮 1mg/kg, 可以对抗低频和中频(2和15Hz)电针的镇痛效应,但不能对抗高频(100Hz)电针镇痛效应。增加纳洛酮剂量至20mg/kg才能部分对抗 100Hz电针镇痛。根据不同剂量纳洛酮(0.25—20mg/kg)对抗不同频率电针镇痛的剂量效应曲线,求得对2,15和100Hz电针镇痛产生50％翻转作用的纳洛酮剂量分别为 0.53,1.02和 24mg/kg。2—15Hz变频电针的镇痛作用也需用大剂量纳洛酮(20mg/kg)才能阻断。实验表明,在三种频率下,改变电针刺激强度(1,2,3V)并不影响纳洛酮翻转电针镇痛的百分数。以上结果表明,纳洛酮翻转电针镇痛的程度决定于电针的频率,不同频率的电针刺激可能在中枢神经系统中释放出不同的内源性吗啡样物质而发挥镇痛作用。     

RAPID METHOD FOR SCREENING THE TOLERANCE OF YEASTS TO ZINC (II) AND CHROMIUM (III)

Rapid screening of the tolerance of yeasts to zinc (II) and chromium (III) was performed by an agar diffusion test. A rapid and reliable procedure for the determination of metal ion concentration gradients on agar plates was developed. Different species of yeasts from the following genera were investigated: Arthroascus, Bulera, Dekkera, Debaryomyces, Dipodascopsis, Eremothecium, Candida, Hansenula, Kluyveromyces, Hormoacus, Geotrichum, Lipomyces, Pachysolen, Pichia, Saccharomyces, Schizosaccharomyces, Schizoblastosporion, Schwan-niomyces, Sporobolomyces, Yarrowia, Torulaspora, Zygosaccharomyces and Williopsis. The experimental conditions were defined as a constant volume of malt agar 32 cm³, and a temperature of 29C. After periods of 24, 47 and 72 h, the concentration intervals of growth inhibition were determined, and the yeasts investigated were grouped in different classes according to their tolerance to Zn (II) and Cr (III). Yeasts were found to be tolerant to significantly higher zinc (II) concentrations in the malt agar medium (5.9 mM to 20 mM) in comparison to chromium (III) (1.5 mM to 6.9 mM). Yeasts showed inter- and intra-generic differences in zinc (II) and chromium (III) tolerance.     

SYNTHETIC STUDIES TO IMPROVE THE DEUTERIUM LABELLING IN NUCLEOSIDES FOR FACILITATING STRUCTURAL STUDIES OF LARGE RNAS BY HIGH-FIELD NMR SPECTROSCOPY

Synthetic studies to prepare ribonucleosides deuterated at C2′ and the application of the developed procedures for the synthesis of ² H ₅ -ribonucleosides from 1,2-O-isopropylidene-3-O-benzyl-ribofuranose-3,4,5,5′- ² H ₄ have been reported.