新疆南北疆灌木植物组成及区系比较

在文献和标本查阅以及野外调查的基础上,比较了北疆和南疆灌木植物的种类、组成及分布区类型的差异,并分析了北疆和南疆灌木植物的相似性。结果表明:新疆共分布有野生灌木植物39科127属462种,其中北疆分布有37科104属350种,南疆分布有28科63属160种。北疆和南疆灌木植物中含2~10种的科最多,分别占北疆和南疆灌木植物总科数的59.5%和60.7%,共有的优势科为菊科(Compositae)、豆科(Leguminosae)和藜科(Chenopodiaceae);在属级水平上均以含1种的属和含2~10种的属占优势。北疆和南疆灌木植物科的分布区类型均以世界广布型和北温带分布型为主,其中,在北疆灌木植物中这2个分布型科的数量分别占总科数的43.2%和32.4%、在南疆灌木植物中分别占总科数的50.0%和28.6%。北疆和南疆灌木植物属的分布区类型均以地中海区、西亚至中亚分布型和北温带分布型为主,其中,在北疆灌木植物中这2个分布型属的数量分别占总属数的26.9%和22.1%、在南疆灌木植物中则分别占总属数的31.7%和27.0%。北疆和南疆灌木植物中分别包含特有种15和8种,此外还包含一些珍稀濒危种类及古老的孑遗种。北疆与南疆灌木植物区系在科、属、种水平上的相似性系数分别为86.1%、69.4%和40.8%,表明在科、属水平上2个区域的灌木植物区系有较为密切的关系。研究结果显示:北疆和南疆灌木植物在种类组成、分布区类型和特有种数量等方面有一定差异,但均具有明显的温带性质,并形成了一系列适应于当地生态环境的生存策略。     

不同菊花品种根系、地上部和叶片相关指标分析及抗逆性评价

采用盆栽法对6个菊花(Chrysanthemum morifolium Ramat.)品种幼苗的根系和地上部相关指标及叶片光合和气体交换参数进行了比较和相关性分析;并基于叶片相对含水量、相对电导率、丙二醛含量和可溶性糖含量4个生理生化指标,采用隶属函数法对不同菊花品种幼苗的抗旱性和耐热性进行了评价.结果表明:不同菊花品种间幼苗的根系和地上部相关指标及叶片光合和气体交换参数存在一定差异.相关性分析结果表明:根系的大多数相关指标与株高呈显著(P<0.05)或极显著(P<0.01)正相关,但与茎粗和单株叶数却没有显著相关性;并且,单株的根体积、根鲜质量和干质量与单株地上部鲜质量呈极显著正相关(相关系数分别为0.598、0.642和0.599),与单株地上部干质量呈极显著或显著正相关(相关系数分别为0.736、0.606和0.553).主根长与净光合速率和蒸腾速率,平均根长与水分利用效率及单株根鲜质量与蒸腾速率呈显著正相关(相关系数分别为0.475、0.517、0.570和0.477);单株根干质量与蒸腾速率及根系活力与净光合速率和水分利用效率呈极显著正相关(相关系数分别为0.641、0.877和0.814).抗逆性评价结果表明:品种'南农红霞'('Nannong Hongxia')、'大白托桂'('Qx073')和'天使'('Angelina')的平均隶属函数值分别为0.93、0.93和0.72,据此判断这3个菊花品种的抗旱性最强;品种'馒头菊'('Cayman')和'南农红霞'的平均隶属函数值分别为0.82和0.70,据此判断这2个菊花品种的耐热性最强.综上所述,不同菊花品种幼苗的根系相关指标差异明显,并且根系生长状况能够影响地上部的生长和发育,品种'南农红霞'的抗旱性和耐热性均很强,具有较高的抗性育种价值.     

Cryogenic changes in proteases and antiprotease activities of buffalo (Bubalus bubalis) and cattle (Bos taurus) semen

The postthaw motility and fertility of buffalo and cattle semen is reduced when they are cryopreserved for artificial insemination. In the present study, an attempt was made to characterize the cryogenic changes in proteases and antiprotease activities (APA) of buffalo and cattle semen because these proteolysis regulators have been reported to be associated with sperm motility and fertility. Buffalo sperm demonstrated at least two major proteases of 45 and 42 kDa and three minor proteases of 95, 52, and 33 kDa. Similarly, cattle sperm demonstrated three major proteases of 62, 45, and 42 kDa and two minor proteases of 85 and 78 kDa. Buffalo seminal plasma demonstrated at least three major proteases of 78, 68, and 62 kDa and one minor protease of 98 kDa and cattle seminal plasma demonstrated one major protease of 68 kDa and two minor proteases of 78 and 75 kDa. Except for the 45 kDa protease, most of the previously mentioned proteases were found to be metalloproteinases. Compared with fresh sperm, cryopreserved buffalo and cattle sperm demonstrated a major protease band of 52/49 kDa and the activity of this protease reduced progressively with the duration of cryopreservation. On the contrary, compared with the fresh seminal plasma, cryopreserved buffalo and cattle semen extenders displayed the presence of a new protease band of 45 kDa and demonstrated that this protease activity was leaked from buffalo and cattle cryopreserved spermatozoa. Buffalo and cattle seminal plasmas displayed at least two major APA of 86 and 26 kDa. Compared with buffalo, cattle seminal plasma demonstrated significantly greater APA. Thus, the present study demonstrated the presence of an array of proteases and APA in buffalo and cattle semen and the activities of which changed during cryopreservation. The leakage of the specific protease activity and changes in the proteases and APA might be attributed to reduced motility and fertility of cryopreserved semen in these species.     

Effect of natural amino acids and sugars on cyclase activities in infusoria Tetrahymena pyriformis and Dileptus anser

Natural amino acids and sugars in intracellular eukaryotes are known to regulate adenylyl cyclase (AC) and guanylyl cyclase (GC) systems that control the most important cell processes. The goal of the present work consisted in study of effects of natural amino acids and sugars and some of their derivatives on AC and GC activities of infusoria Tetrahymena pyriformis and Dileptus anser. Methionine, arginine, lysine, and tryptamine stimulated basic AC activity of T. pyriformis, whereas alanine, thyrosine, and cysteine decreased it. Methionine, glycine, alanine, thyrosine, arginine, and to the lesser degree tryptamine and histidine stimulated AC of D. anser. The GC activity of T. pyriformis are increased in the presence of tryptamine, tryptophane, histidine, arginine, and lysine, whereas glycine and aspartic acid, on the contrary, decreased it. Tryptamine, tryptophan, leucine, glutamic acid, serine, histidine, and alanine stimulated the GC activity of D. anser. Glucose, fructose, and sucrose stimulated the basal AC activity of both infusorians and GC of T. pyriformis, with glucose and sucrose increasing AC of T. pyriformis twice, while that of D. anser 4.5 times. Lactose stimulated AC and GC of T. pyriformis and was inefficient with respect to the D. anser cyclases, whereas mannose and galactose did not affect the enzyme activities in both infusorians. The study of the chemotactic response of infusorians to amino acids and sugars indicates that involved in realization of this response can be signaling pathways both dependent on and independent of cyclic nucleotides. Thus, it has been established for the first time that several amino acids and sugars affect functional activity of enzymes with cyclase activity of the infusorians T. pyriformis and D. anser. This confirms the hypothesis that at early stages of evolution the large spectrum of comparatively simple natural molecules has a hormone-like action.     

史前人类的生存之火

用火是人类独有的行为能力,对人类的生存演化至关重要。用火熟食改善了人类的营养,导致人类生物特性发生一系列改变,人口、行为、社会关系和生存方式也发生相应变化。用火使人类获得更多的生存资源,并帮助人类改变工具与用具的材料特性,如对石料做热处理,进而发明了陶器和金属工具,开启了文明的历程。人类与火的互动是一个长期、曲折的过程,经历了偶尔利用自然火、时断时续对火控制和使用、有效保存火种乃至人工取火形成用火的日常习惯,进而发展到现代无所不在、不可或缺的复杂用火。人类用火被认为始于直立人的诞生,但目前提取到的证据指向150万年前。早期人类用火证据的提取和论证存在极大的困难和挑战,需要精细的野外工作,做高精度的遗址埋藏和遗物遗迹的空间分析,须采用现代科技手段和模拟实验对地层沉积物和燃烧物证做微形态、成分、色度、磁化率、微体植物化石等尽可能多的宏观和微观分析,排除自然因素的干扰,这样得出的结论才会坚实可信。本文介绍了人类用火的历史、作用和对用火证据提取与分析的思路、方法与技术,通过一系列案例阐述人类用火的方式、发展演化过程和考古学家为破译远古人类用火的谜团所做的努力和取得的成果,以期对这项意义重大但常被忽视的研究起到推动作用。     

Interaction of phosphorus and molybdenum in relation to uptake and utilization of molybdenum,phosphorus, zinc,copper and manganese by rice

Summary The effect of phosphorus and molybdenum alone and combined, on the uptake and utilization of Mo, Mn, Zn, Cu and P by rice (Var. IR-579) was studied in the greenhouse at varying levels of Mo (0, 2.5 and 5.0 ppm) and (0,100 and 200 ppm). Application of P increased the dry matter yield of shoot and root. Combined application of P and Mo increased the dry matter yield of shoot. Application of Mo increased the concentration of Mo and P in shoot. Applied P caused an increase in the concentration of Mo, Zn and P in shoot. Combined application of P and Mo resulted in an increase in concentration and uptake of Mo in shoot.     

T.l.c. enantiomeric separation of amino acids

Resolution of enantiomers is very important particularly in the fields of asymmetric synthesis, mechanistic studies, geochronology, studies of structure-function relationship of proteins, pharmacology, and medicine. Various chromatographic methods have replaced the classical fractional crystallization, seeding and enzymatic procedures. Of these, t.l.c. provides a direct, simple, and inexpensive method for resolution of enantiomers of amino acids and their derivatives. Ligand exchange, ion exchange, and molecular inclusion complexation have been the basis of t.l.c. resolution of enantiomers of amino acids and their derivatives. The innovation of new plate types, and methods of development and detection have renewed interest in the direct resolution of enantiomers of amino acids, their derivatives and a variety of other compounds by t.l.c. The present report provides an overview of some of the more recent approaches to the direct t.l.c. resolution of amino acids and their derivatives together with special advantages and scope of t.l.c.     

Morphology and histochemistry of ovarian changes in the field rat, Millardia meltada

A study has been made of the morphological and histochemical changes of the ovary of the field rat, Millardia meltada during its oestrous cycle and pregnancy. The follicular growth and atresia, ovulation and formation of corpora lutea occur throughout the year except severe winter months (December and January). Fluctuations in the follicular development occur on different days of the oestrous cycle and pregnancy. The granulosa cells show a progressive increase in their size in successive stages of follicle growth. The granulosae of normal follicles show some sparsely scattered lipid bodies which consist of phospholipids. Theca interna cells during follicular growth develop diffuse lipoproteins and lipid droplets consisting of triglycerides, phospholipids and cholesterol and/or its esters. The luteal cells of corpora lutea are formed by the granulosa cells as the theca interna cells degenerate and disappear. The fibroblast-like cells of thecal origin, alongwith the blood vessels, invade the luteal cell mass. The luteal cells during metoestrus, dioestrus and first half of pregnancy show abundant diffuse lipoproteins and a few lipid droplets composed mainly of phospholipids and some triglycerides, which are indicative of active steroidogenesis. The details of degenerative histological and histochemical alterations of corpora lutea during oestrous cycle and pregnancy are also described and discussed. Morphological and histochemical changes of follicular atresia are described. The granulosa cells of atretic follicle degenerate and disappear leaving behind theca interna cells which form patches of interstitial gland cells during the reproductive activity of the present rat. Interstitial gland cells show diffusely distributed sudanophilic lipoproteins and lipid droplets consisting of triglycerides, cholesterol and/or its esters and some phospholipids, which are indicative of steroidogenesis. The functional significance of histological and histochemical changes, which occur in various components of the ovary during oestrous cycle and pregnancy, has been discussed.     

5种野牡丹属植物花色素成分及影响花色呈色因子分析

为明确野牡丹属(Melastoma L.)植物花瓣的色素成分和呈色机理,为花色育种提供参考。以野牡丹(M.candidum)、白花野牡丹(M.candidum f.albiflorum)、印度野牡丹(M.malabathiricum)、白花印度野牡丹(M. malabathricumvar.alba)、毛稔(M.sanguinrum)5种野牡丹属植物材料,采用目测法、RHSCC比色法和色差仪测定花瓣表型,应用化学显色法、紫外分光光度法对花色素成分及含量进行初步分析与测定,通过徒手切片组织切片法观察花瓣表皮细胞的显微结构和分布特点,测定花瓣pH值、可溶性糖及可溶性蛋白含量等生理指标分析对花色的影响。结果显示,野牡丹属植物花瓣不含叶绿素和类胡萝卜素,紫罗兰色系主要含花青素苷和黄酮类化合物,白色系主要含黄酮类化合物。野牡丹和毛稔花色素分布于上、下表皮,印度野牡丹花色素分布于上、下表皮和栅栏组织,白花野牡丹和白花印度野牡丹花瓣没有发现色素积累;紫罗兰色系野牡丹上表皮细胞呈圆锥形突起,白色系野牡丹上表皮细胞呈不规则的扁平状,它们下表皮细胞全呈不规则的扁平状。野牡丹属植物花色明度L*随花瓣颜色变深而降低,明度L*与红度a*呈极显著负相关、与蓝度b*呈极显著的正相关。花瓣中花青素苷含量与其明度L*和蓝度b*呈显著负相关,pH值与花瓣红度a*呈现显著的负相关。研究表明,野牡丹属植物花色主要由花青素苷决定,花青素苷含量、色素分布、上表皮细胞形状等是引起花色呈现多样的主要因子。     

云南省新平县家鼠鼠疫疫原地小肠结肠炎耶尔森菌的调查分析

目的了解新平县家鼠鼠疫疫源地小肠结肠炎耶尔森菌的分布及病原学特征。方法采集家鼠盲肠、舌头和猪粪便、咽喉粘液以及腹泻患者粪便标本进行小肠结肠炎耶尔森菌的检测与分析。结果检测家鼠盲肠、鼠舌头、猪粪便、猪咽喉粘液物、腹泻患者粪便的标本数分别为722、722、467、237和107份,共分离到61株小肠结肠炎耶尔森菌,总检出率为2. 71%,5种标本的检出率分别为2. 63%、1. 39%、3. 85%、2.53%和7. 48%,差异有统计学意义（x^2= 16. 422,P = 0. 003）;分离株包括致病株10株、非致病株51株,有1A、2、3三种生物型和0：3、0：5、0：8等多种血清型,以及六种毒力基因型。猪、鼠、腹泻患者标本检出致病菌株数分别为9、1、0株。结论新平县家鼠鼠疫自然疫源地猪、鼠、腹泻患者是小肠结肠炎耶尔森菌的重要宿主,分离菌株具有遗传多样性,猪、鼠是小肠结肠炎耶尔森菌病的主要传染源。     

黄土高原小叶杨与其他树种枯落叶混合分解对土壤性质的影响

将小叶杨分别与其他11个树种枯落叶粉碎混合后进行室内分解培养,分析不同树种枯落叶混合分解对土壤性质的影响及其相互作用.结果表明:12个树种枯落叶单独混土分解均明显提高了土壤脲酶、脱氢酶、磷酸酶活性和有机质、碱解N含量,但对土壤速效P含量和土壤阳离子交换量(CEC)的影响差异较大,其中柠条和紫穗槐枯落叶改善土壤性质的效果明显.小叶杨分别与油松、侧柏、刺槐、白榆枯落叶混合分解,对土壤微生物数量的影响存在相互促进作用;小叶杨分别与侧柏、柠条枯落叶混合分解对土壤有机质、速效P、速效K含量和CEC的影响存在相互促进作用,但对土壤大部分酶活性的影响却存在相互抑制作用;小叶杨与落叶松枯落叶混合分解对土壤多数酶活性和养分含量的影响存在相互促进作用,而与樟子松枯落叶混合分解时则有抑制作用.总体上,小叶杨分别与白榆、油松、落叶松和刺槐枯落叶混合分解可促进土壤性质的改善,而与侧柏、柠条、樟子松、沙棘和紫穗槐枯落叶混合分解时则相互抑制.     

Mold flora and aflatoxin contamination of stored and cooked samples of pearl millet in the Paharia tribal belt of Santhal paragana, Bihar, India.

Stored and cooked samples of pearl millet (Pennesetum typhoides), which is regularly consumed as food by the Paharia tribe in the hilly regions of Santhal Pargana, Bihar State, India, that were harvested in January 1989 were analyzed for mold flora, natural occurrence of Aspergillus flavus and A. parasiticus, and incidence and levels of aflatoxin B1. Of the 22 fungal species isolated, A. flavus and A. parasiticus were the predominant species (63.8%) during the rainy season, followed by other species of Aspergillus, Penicillium, Fusarium, Rhizopus, Helminthosporium, and Curvularia. Screening of 169 A. flavus and A. parasiticus strains showed that 59 of them were toxigenic, producing various combinations of aflatoxins B1, B2, G1, and G2. The amounts of aflatoxin B1 ranged between 4 and 30 mg/100 ml of liquid medium. Analysis of stored and cooked samples also revealed a high incidence and alarming levels of naturally produced aflatoxin B1. Forty-nine of 75 stored and 16 of 38 cooked samples contained various combinations of aflatoxins. The levels of aflatoxin B1 ranged between 17 and 2,110 ppb in stored samples and 18 and 549 ppb in cooked samples. The correlation of insect damage with A. flavus and A. parasiticus incidence and quantity of aflatoxin B1 was found to be insignificant.     

Local and landscape drivers of biodiversity of four groups of ants in coffee landscapes

Agriculture of varying management intensity dominates fragmented tropical areas and differentially impacts organisms across and within taxa. We examined impacts of local and landscape characteristics on four groups of ants in an agricultural landscape in Chiapas, Mexico comprised of forest fragments and coffee agroecosystems varying in habitat quality. We sampled ground ants found in leaf litter and rotten logs and arboreal ants found in hollow coffee twigs and on tree trunks. Then using vegetation and agrochemical indices and conditional inference trees, we examined the relative importance of local (e.g. vegetation, elevation, agrochemical) and landscape variables (e.g. distance to and amount of nearby forest and rustic coffee) for predicting richness and abundance of ants. Leaf litter ant abundance increased with vegetation complexity; richness and abundance of ants from rotten logs, twig-nests, and tree trunks were not affected by vegetation complexity. Agrochemical use did not affect species richness or abundance of any ant group. Several local factors (including humus mass, degree of decay of logs, number of hollow twigs, tree circumference, and absence of fertilizers) were significant positive predictors of abundance and richness of some ant groups. Two landscape factors (forest within 200 m, and distance from forest) predicted richness and abundance of twig-nesting and leaf litter ants. Thus, different ant groups were influenced by different characteristics of agricultural landscapes, but all responded primarily to local characteristics. Given that ants provide ecosystem services (e.g. pest control) in coffee farms, understanding ant responses to local and landscape characteristics will likely inform farm management decisions.     

Turnover of low density lipoproteins in normal and atherosclerotic rabbits

The turnover and composition of normal and hyperlipemic (h.l.) low density lipoproteins (LDL) of rabbits, were studied. They were obtained by ultracentrifugation and labeled by Bolton and Hunter method. Normal and h.l. LDL labeled with 125I were injected directly and crossed to both groups of rabbits. Normal and h.l. LDL had a different protein/lipid ratio. The analysis of fractional catabolic rate of LDL and the half-life of the phases of rapid and slow decay, show that h.l. LDL had a fractional catabolic rate that is the half of normal LDL and an increased half life of the phases of rapid and slow decay. Apparently, two factors: a) defective LDL receptor in the h.l. rabbit and b) different physico-chemical properties between normal and h.l. LDL, would be the reason for this difference. Besides, when normal and h.l. 125I LDL were injected into h.l. and normal rabbit, respectively, LDL changed according to the injected rabbit, as can be deduced from the analysis of the half life of the phase of slow decay.     

Measuring the Evolution of Ontology Complexity: The Gene Ontology Case Study

Ontologies support automatic sharing, combination and analysis of life sciences data. They undergo regular curation and enrichment. We studied the impact of an ontology evolution on its structural complexity. As a case study we used the sixty monthly releases between January 2008 and December 2012 of the Gene Ontology and its three independent branches, i.e. biological processes (BP), cellular components (CC) and molecular functions (MF). For each case, we measured complexity by computing metrics related to the size, the nodes connectivity and the hierarchical structure.The number of classes and relations increased monotonously for each branch, with different growth rates. BP and CC had similar connectivity, superior to that of MF. Connectivity increased monotonously for BP, decreased for CC and remained stable for MF, with a marked increase for the three branches in November and December 2012. Hierarchy-related measures showed that CC and MF had similar proportions of leaves, average depths and average heights. BP had a lower proportion of leaves, and a higher average depth and average height. For BP and MF, the late 2012 increase of connectivity resulted in an increase of the average depth and average height and a decrease of the proportion of leaves, indicating that a major enrichment effort of the intermediate-level hierarchy occurred.The variation of the number of classes and relations in an ontology does not provide enough information about the evolution of its complexity. However, connectivity and hierarchy-related metrics revealed different patterns of values as well as of evolution for the three branches of the Gene Ontology. CC was similar to BP in terms of connectivity, and similar to MF in terms of hierarchy. Overall, BP complexity increased, CC was refined with the addition of leaves providing a finer level of annotations but decreasing slightly its complexity, and MF complexity remained stable.     

黄斑篮子鱼和金钱鱼鳃的扫描电镜观察

对两种鲈形目鱼类黄斑篮子鱼(Siganus oramin)和金钱鱼(Scatophagus argus)的鳃结构进行扫描电镜观察。结果表明,黄斑篮子鱼和金钱鱼鳃的表面结构及微细结构与其他硬骨鱼类基本相似,鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。黄斑篮子鱼的鳃片中部鳃丝表皮有大量凸起,而端部鳃丝表皮的凹凸程度明显较低,黄斑篮子鱼的鳃小片高度较金钱鱼鳃小片高。黄斑篮子鱼和金钱鱼鳃上皮的扁平上皮细胞、氯细胞和黏液细胞的形态结构及数量分布存在细微的差异。黄斑篮子鱼鳃片鳃丝的端部和中部表面有黏液细胞,金钱鱼鳃丝表面的黏液细胞很难观察到,与大多数淡水鱼类相似。黄斑篮子鱼鳃丝表面分布的氯细胞数量多于金钱鱼,这可能与两种鱼生活环境、生活习性的长期演变相关。     

扎龙湿地不同生境芦苇分株的形态特征及生物量分配的异速关系

不同环境条件下的植物个体可以表现出形态特征的分异和物质分配的权衡与调整。采用大样本抽样调查与统计分析方法,比较研究扎龙湿地不同生境芦苇(Phragmites Australis)生殖株和营养株的形态特征以及生物量分配的异速关系。结果表明：在9月末,盐碱生境、旱生生境、湿生生境和水生生境芦苇分株的生长表现出较大的生态可塑性,株高和株重均以盐碱生境最小,水生生境最大,最大值与最小值的比值分别为1.3—3.3和1.8—5.1,分株生长在种群间的变异度高于种群内,与营养株相比,生殖株的变异度较低;分株的支持分配与生产分配的比值为1.8—4.2,生产分配以盐碱生境最高,以水生生境最低,而支持分配和生殖分配表现与生产分配相反的序位;生殖株的花序长和花序重与株高间呈直线函数形式增长,株高和株重低于种群平均值的20%和35%的分株不进行有性生殖;叶重、叶鞘和茎重以及分株重与株高间呈幂函数形式的异速生长关系。植物通过改变个体的形态特征以及调整构件间生物量分配适应不同环境,而受遗传因素控制的构件间生长关系却相对稳定。     

Role of canopy height in the resistance of Lycopersicon hirsutum f. glabratum to Tuta absoluta (Lep., Gelechiidae)

The objective of this work was to study the effect of plant canopy height on the resistance of the tomato species Lycopersicon hirsutum to the tomato leafminer Tuta absoluta . Determination of the levels of tridecan-2-one (2-TD) and undecan-2-one (2-UD) in L. hirsutum , as well as the leaf area, density and types of trichomes present in L. hirsutum and L. esculentum were made on apical, medium and basal parts of plant canopy. Correlation of these data were made with the following biological characteristics of T. absoluta : rates of oviposition and egg hatching; length of egg, larval and pupal stages; mortality of the larval and pupal stages; pupal weight; and sex ratio. Levels of 2-TD on leaves of L. hirsutum increased from bottom to top of canopy. Tuta absoluta had higher oviposition and egg hatching, as well as lower mortalities and smaller larval and pupal periods in L. esculentum than in L. hirsutum . Longer pupal period and greater number of small and large mines of T. absoluta were verified in the apical and medium parts of L. hirsutum plants. On the other hand, higher pupal mortality and longer larval periods were obtained in the apical and basal parts of the L. hirsutum plants. Larval mortality was higher in the basal part of those plants. In L. esculentum , leaves from the apical part of the plant promoted lower mortality, longer larval period and greater number of large mines of T. absoluta . However, a shorter pupal period was verified on leaves of the basal part. It appears that an increase in glandular trichome density in L. hirsutum leads to an increase in the levels of 2-TD, which, in turn slows down larval development.     

Carassotrema koreanum Park, 1938 (Trematoda, Waretrematidae) and a new species of this genus from fresh water fishes of North Vietnam]

In freshwater fishes of North Viet-Nam were found representatives of the family Waretrematidae, Carassotrema koreanum and a new species of this genus, C. ginezinskajae sp. n., close to C. koreanum and differing from it in the structure and extent of yolk glands, relatively larger sizes of the pharynx and suckers, the location of spines and body shape. The described species differs from the other species of this genus, C. mugilicola, in the shape and location of testis, structure and location of yolk glands, intestine extent, size of suckers and pharynx, presence of cirrus, location of spines on the body and in other characters. Asymphylodora pavlovskajae Ha Ky, 1969 and Asymphylodora ginezinskajae Ha Ky, 1969 are reduced to synonyms of Carassotrema koreanum and C. ginezinskajae sp. n.     

Detection of coliform bacteria in water by polymerase chain reaction and gene probes

Polymerase chain reaction (PCR) amplification and gene probe detection of regions of two genes, lacZ and lamB, were tested for their abilities to detect coliform bacteria. Amplification of a segment of the coding region of Escherichia coli lacZ by using a PCR primer annealing temperature of 50 degrees C detected E. coli and other coliform bacteria (including Shigella spp.) but not Salmonella spp. and noncoliform bacteria. Amplification of a region of E. coli lamB by using a primer annealing temperature of 50 degrees C selectively detected E. coli and Salmonella and Shigella spp. PCR amplification and radiolabeled gene probes detected as little as 1 to 10 fg of genomic E. coli DNA and as a few as 1 to 5 viable E. coli cells in 100 ml of water. PCR amplification of lacZ and lamB provides a basis for a method to detect indicators of fecal contamination of water, and amplification of lamB in particular permits detection of E. coli and enteric pathogens (Salmonella and Shigella spp.) with the necessary specificity and sensitivity for monitoring the bacteriological quality of water so as to ensure the safety of water supplies.