Natural Enemies ofTrapaspp. in Northeast Asia and Europe

Trapa natansis an aquatic plant native to the Old World. In the late 1880s this plant was found to be naturalized in the eastern United States where it has become an important weed. To evaluate the potential of biological control to reduce this weed, surveys for natural enemies ofTrapaspp. were made in Northeast Asia and Europe. In addition, populations ofTrapa japonicain South Korea were monitored for one season to evaluate the occurrence and impact of insect natural enemies. Among the insects found, the leaf beetleGalerucella birmanicawas the most common and damaging species in Asia. It can cause complete defoliation of whole populations of plants. Nymphuline pyralid moths were also common and at times damaging. Both the beetle and the moths feed and develop on unrelated plants and so have no potential as biological control agents ofT. natansin North America. TwoNanophyesweevils were found in Asia which feed in petiole floats of the leaves. They are thought to be specific toTrapabut were not observed to be damaging. Low level populations of polyphagous Homoptera were common. Chironomid midges were also frequently associated with the plants, but for the most part were filter feeders, not herbivores. The greatest impact on the monitored plants in South Korea was by the leaf beetleG. birmanicawhich defoliated most of the plants, causing the mats of plants to sink. In Europe, a similar and related insect fauna was found, but none of the insects was very damaging to the plants. One Italian weevil,Bagous rufimanus,feeds within the fruit stems and might be more damaging at higher than observed population levels. Some diseases were seen on some plants in both regions. European populations ofT. natanshave declined significantly, stimulating conservation efforts. Literature records ofTrapainsects from warm areas are presented. These could be of interest ifT. natansspreads into warmer areas of North America.     

浙江水源地河流浮游动物多样性与环境因子的通径分析

为探明水源地河流浮游动物多样性及与水环境因子的关系, 利用浮游动物多样性参数监测水质, 2010-2014年间, 我们于每年的冬季(1月)、春季(4月)、夏季(7月)和秋季(10月), 对浙江2个水源地河流采样站(H1站和H2站)展开浮游动物种类组成、丰度和多样性指数的季节性调查, 同时测定水环境因子。结果表明, H1站和H2站浮游动物平均丰度分别为1,387.4 ind./L和873.0 ind./L, 小型浮游动物(轮虫 + 桡足类无节幼体)丰度分别占92.8% (H1站)和91.5% (H2站)。两采样站轮虫、枝角类和桡足类的优势种均为针簇多肢轮虫(Polyarthra trigla)、短尾秀体溞(Diaphanosoma brachyurum)和温剑水蚤(Thermocyclops sp.)。多元逐步回归与通径分析结果表明: 冬季氮磷比是轮虫类Shannon-Wiener多样性指数(H′)波动的限制因子, 主要通过总磷含量对轮虫类H′指数产生较大的间接正向作用; 春季氮磷比是轮虫类H′指数发展的决策因子; 秋季氮磷比可通过总氮含量对轮虫类H′指数产生较大的间接正向作用。冬季氨氮、总氮含量分别是甲壳动物体积多样性指数(Hs)的决策因子和限制因子。夏季溶解氧含量是总浮游动物物种丰富度(d)波动的限制因子, 主要通过pH值对d指数产生较大的间接正向作用, 作用机制表现为轮虫类H′指数随着夏季溶解氧含量的升高呈极显著上升(P < 0.01), 而甲壳动物Hs指数则显著下降(P < 0.05)。水源地河流环境因子与浮游动物多样性之间的相互关系为浙江水源地生态学监测提供了可能性。     

10种菊科植物水提液对小麦幼苗生长的影响

用小白酒草、黄鼠草、刺儿菜、一年蓬、苍耳、苦苣菜、旋覆花、紫菀、黄花蒿、野塘蒿等10种菊科植物的水提液,对小麦进行不同浓度的皿内沙培实验,分别对小麦的根长、苗高及鲜重等三项指标进行测定的统计结果表明：10种菊科植物水提液对小麦幼苗生长的影响依种类有差异,其中旋覆花、黄花蒿、野塘蒿、紫菀对小麦表现出明显克生作用,而小白酒草、黄鼠草则表现出一定的促生作用;刺耳菜、一年蓬、苍耳对小麦幼苗生长的影响不明显。     

冬小麦生长季不同灌溉模式对冬小麦-夏玉米产量与水分利用的影响

在华北平原黑龙港流域对冬小麦实行3种灌溉模式,研究了不同灌溉模式对冬小麦-夏玉米产量、耗水特性和水分利用效率的影响.结果表明:浇底墒水+拔节水处理(W2,75 mm+90 mm)和浇底墒水+拔节水+灌浆水处理(W3,75 mm+90 mm+60 mm)周年总产量均显著高于只浇底墒水处理(W1,75 mm),增幅分别为8.7%和12.5%.冬小麦全生育期对土壤水的消耗随灌溉量的增加而减少,夏玉米季总耗水量随冬小麦季灌溉量的增加而增加.W2处理冬小麦水分利用效率(WUE)比W3处理高11.1%,而其夏玉米水分利用效率(WUE)与W3处理差异不显著.W2和W1处理的周年水分利用效率(WUET)分别为21.28和21.60 kg.mm-1.hm-2,比W3处理分别高7.8%和9.4%.综合周年产量、耗水量和水分利用效率,W2是较好的节水丰产灌溉模式.     

Coccidian Parasites (Apicomplexa: Eimeriidae) of Nerodia spp. (Serpentes: Colubridae), with a Description of a New Species of Eimeria

Eimeria conanli n. sp. (Apicomplexa: Eimeriidae) is described from intestinal contents and feces of Nerodia erythrogaster transversa and N harteri harteri from northcentral Texas. Oocysts of the new species are ellipsoid in shape. 17.9 × 13.0(15–21 × 12–15) μm, with a smooth, thin, single-layered wall; shape index 1.4 (1.2–1.5). One to several (usually 2) polar granule(s) and an oocyst residuum are present, but a micropyie is absent. Sporocysts are elongate, 12.9 × 5.2 (13–15 × 5–6) -m, apparently without a true Stieda body structure. Each sporoeyst contains an ellipsoid residuum, 3.9 × 3.2 (3–6 × 2–4) μm, and elongate sporozoites, 11.4 × 2.5 (10–14 × 2–3) μm in situ, each with a spherical or subspherical anterior refractile body and spherical to ellipsoid posterior refractile body. In addition to the new species, oocysts of 4 previously described eimerians from colubrid snakes were found in these hosts.     

金华北山三种啮齿动物身体热值、脂肪和水分含量的研究

研究了浙江金华３种啮齿动物的身体热值,脂肪含量和水分含量。成年社鼠、褐家鼠和白腹巨鼠生物量热值季节变动范围分别为６．２０９７－７．６５７ＫＪ／ｇ,６．１５３－７．０９６ＫＪ／ｇ,６．１９９－１２．０３３ＫＪ／ｇ;水分含量为６６．６４％－６９．７５％,６７．４８％－７０．１９％,５４．６４％－７２．３７％;灰分含量不存在季节差异,年平均值分别为１２．５０％,１２．２３％,１０．４９％。神鼠脂肪含量春     

Possible mechanisms of afterripening in Xanthium seeds

Breaking dormancy in some seeds requires a period of dry storage. In the seeds of Xanthium pennsylvanicum Wallr., the process of afterripening proceeds optimally at water contents between 7 and 14%: this range of dehydration can be identified with water binding region 2, in which water is bound with low enthalpy. At water contents below 7%. Seeds remained primarily dormant over 3 years. Attempts to alter the afterripening with atmospheres of elevated nitrogen showed no effect. and with oxygen there was no consistent effect. There were no changes is osmotic value of the seed sap, or in its sugar or amino acid contents. We speculate that afterripening in Xanthium may involve some nonenxymatic reactions which remove substances which inhibit germination. Candidates for these reactions include the Amadori and Maillard reactions.     

Growing a stratified,cornified primary culture of rat keratinocytes with epidermis-like water permeation barrier function

Summary The culture of cutaneous keratinocytes grown on a Puropore nylon microporous membrane at the air-liquid interface has been shown to be similar to the epidermis in a number of molecular and morphologic characteristics but to exhibit a significantly greater degree of tritiated water permeation. Various culture conditions have been altered in an effort to improve the water barrier properties. A Kp value in the range of 5.5±1.6×10⁻³ has been obtained for 79% of the culturea) by plating 0.9×10⁶ viable basal cells on a piece (13-mm diameter) of membrane for 7 days of submerged growth,b) by placing two membranes on two stacked glass fiber filters (47-mm extra-thick) in a culture dish (60 mm) for 14 days of growth at the air-liquid interface,c) by replacing the growth medium, i.e., 1 ml of complete minimum essential medium (CMEM) every 24 h after lifting,d) by using 10% fetal bovine serum (FBS) in the CMEM during the submerged culture period and 15% FBS in the CMEM during the lifted culture period, ande) by adding a dialysis membrane on top and a Puropore nylon membrane below the culture when the cultures were inserted in the permeation cell for testing. The percentage of cultures with this value for Kp can be increased to 90% if only cultures with yellow, smooth, and shiny surfaces are tested. This system should be useful as a replacement for skin in testing the cutaneous permeation of some chemicals. To whom correspondence should be addressed at 1528 Public Health, The University of Michigan, Ann Arbor, Michigan 48109-2029.     

Flavonoid glycosides of the roots of Glycyrrhiza uralensis

The structure of a flavanone glycoside from the roots of Glycyrrhiza uralensis has been confirmed as 4′-O-[β-d-apio-d-furanosyl-(1 → 2)-β-d-glucopyranosyl]liquiritigenin. In addition, two known flavonoid glucosides, ononin (a minor component) and liquiritin (a major component), were isolated from the same extract.