沿海防护林四个树种根系分布对盐胁迫的响应

研究盐分胁迫下植物根系的分布及生长特性对沿海防护林树种的筛选具有重要意义。以8年生女贞(Ligustrum lucidum)、洋白蜡(Fraxinus pennsylvanica)、木麻黄(Casuarina equiestifolia)和墨西哥落羽杉(Taxodium mucronatum)等4个亚热带沿海防护林树种为对象,对其根系生长特性与土壤盐度关系、根系生物量分配格局、功能根的分布特征以及根系的比根长和根长密度进行了比较。结果表明:1)土壤盐分对植物根系垂直生长与分布具有强烈的制约作用,根系的水平伸展能力与树种根系垂直生长呈负相关;2)不同树种适应盐分胁迫能力不同,导致各自功能根的生物量分配格局差异;3)根径级越小,其吸收水分和营养物质的能力越强;根径级越大,固定和支持植株的能力越强;4)墨西哥落羽杉盐分阈值0.45%,根系垂直分布在0～95cm的土层中,具有良好的抗台风和耐盐土能力;木麻黄和洋白蜡2个树种的主根系长度分别为25cm和29cm,支撑根的比例分别为87.2%和56.3%,因此也具有一定的抗台风能力,可以栽植在盐度0.36%的沿海滩涂上;女贞盐分阈值0.21%,垂直根系为20cm,支撑根比例51.0%,不适合栽植于高盐分的台风分布地理区域。     

Germination response of four pasture species to temperature,light, and post-harvest period

Abstract

The purpose of this research was to explore the effect of temperature, light, and post-harvest period, and their interactions, on seed germination ecology of four common pasture species in the Mediterranean environment. Mature seeds of Diplotaxis erucoides, Hirschfeldia incana, Hyoseris scabra (Mediterranean distribution) and Sonchus oleraceus (cosmopolitan distribution) were subjected to seven constant temperatures (10–40°C, at intervals of 5°C) under continuous darkness, or a 12 h/12 h light/dark photoperiod at 30, 150 and 270 days after harvest (DAH). Cumulative germination and germination speed were determined. In all the tested species, except S. oleraceus, light significantly enhanced germination. S. oleraceus seeds maintained germination values over 90%, in a wide range of temperatures (10–35°C), in the dark as well as in light. Seeds of H. incana germinated well soon after seed dispersal. In D. erucoides and H. scabra, germination increased with storage period, while in S. oleraceus there was no effect of seed age. In all the species, moreover, no germination was recorded at 40°C. Temperature, light, and post- harvest requirement may be regarded as an adaptation strategy to ensure optimal conditions for seedling development and survival in Mediterranean species, while the species with a cosmopolitan distribution germinates under almost all tested conditions.     

Incubation temperature critical to successful stimulation of in vitro zygotic embryo growth in four Australian native Cyperaceae species

Many species of Western Australian Cyperaceae (sedges) are vital components of the indigenous flora but commonly display low seed set, poor seed quality and intractable seed dormancy. We report the effects of incubation temperature and in vitro growth media on whole seed germination compared with extracted zygotic embryo growth in Tetraria capillaris, T. octandra, Lepidosperma drummondii and L. tenue. No germination was observed from intact whole seeds of all test species regardless of the treatment evaluated. In contrast, excised zygotic embryos of all study species exhibited significant increases in growth when cultured at 15°C compared to embryos incubated at 25°C; however, optimal media for embryo growth were genera specific. Extracted embryos of T. capillaris and T. octandra exhibited maximum percentage growth (30 and 40%, respectively) at 15°C on ½ MS medium with no plant growth regulators required. In the case of L. drummondii and L. tenue 1 μM thidiazuron was a necessary addition to the ½ MS medium resulting in 40 and 77% growth of embryos (at 15°C), respectively. Incubation of extracted embryos at 25°C (regardless of medium treatment) resulted in <10% embryo growth for T. octandra and L. tenue, while the remaining two species (L. drummondii, T. capillaris) showed no embryo growth at 25°C on any medium treatment.     

Length‐weight relationships of four freshwater fish species from the coastal drainage system in Peru

The morphometric relationships of three native and one exotic freshwater fish species from the Lower San Juan and Lower Pisco River basins, central Coast of Peru, are presented. Specimens were collected in May and November 2010 using seine nets and electrofishing. Length‐Weight (LWR) relationships for Andinoacara stalsbergi, Trichomycterus punctulatus, Basilichthys archaeus and Poecilia reticulata are provided for the first time, contributing information towards the effort to conserve freshwater fishes.     

异极衣纲一新种和四中国新记录分类单元

异极衣纲Lichinomycetes仅含异极衣目Lichinales,异极衣目内含3科：球蜂窝衣科Gloeoheppiaceae、异极衣科Lichinaceae和盾衣科Peltulaceae。本文基于表型特征对中国异极衣纲地衣分类研究发现新种1个：近叉指盾链衣Digitothyrea subdivergens,中国新记录属1个：指盾链衣属Digitothyrea,中国新记录种3个：白棋盘蜂窝衣Heppia solorinoides、朝氏盾链衣Thyrea asahinae和吉拉氏盾链衣Thyrea girardii,与形态相似种进行了比较和讨论。本研究不仅为中国地衣志的编研积累资料,同时为开展利用地衣结皮实施“沙漠生物地毯工程”储备资源信息。     

Record of five new endemic small mammal hosts for four ectoparasite species from Sri Lanka

Both ticks and fleas are medically important arthropods, which act as vectors for a number of zoonotic diseases. In Sri Lanka, 35 species of ticks and 20 species of fleas have been reported from mammals, birds and reptiles. However, records of these parasites from small mammals are scanty. Here, we report ticks and fleas infesting muroid rodents and shrews including endemic species collected from around the country. Of the 149 small mammals collected, 48 individuals were infested with ticks, fleas or both. Immature stages of three tick species, Ixodes ceylonensis, Haemaphysalis hystricis and Hyalomma brevipunctata and unidentified species of Rhipicephalus were recorded from ten small mammal species. Four species of fleas, Stivalius phoberus, Stivalius aporus, Lentistivalius ferinus and Nosopsyllus tamilanus were identified from five species of small mammals. We report new host species for I. ceylonensis (Crocidura miya, Suncus montanus and Solisorex pearsoni), S. aporus (S. montanus and Mus fernandoni), N. tamilanus (S. pearsoni) and Rhipicephalus spp. (Crocidura hikmiya, S. montanus, S. pearsoni, M. fernandoni). All new host species reported here are endangered or critically endangered endemics to Sri Lanka.     

Germination responses of four native terrestrial orchids from south-west Western Australia to temperature and light treatments

We report an investigation into the impact of temperature and illumination on in vitro symbiotic and asymbiotic germination of the threatened taxon Caladenia huegelii, and three other orchid spp. namely—Caladenia latifolia, Microtis media and Pterostylis sanguinea, all species from south-west Western Australia, a recognized biodiversity hotspot. High symbiotic germination on oatmeal agar (OMA + fungal symbionts specific to each species) was recorded in three species in continuous dark incubation i.e. C. huegelii seeds (98 % germination at 25 °C), and M. media and P. sanguinea (93 and 98 % respectively at 20 °C). Highest symbiotic germination for C. latifolia (100 %) was observed at 15 and 20 °C under light treatment (12/12 h light/dark). Low temperature incubation (10 °C) significantly suppressed symbiotic germination/development of seedlings across all species. Asymbiotic media treatments assessed (OMA minus fungal symbionts, Pa₅ and ½ MS), failed to stimulate any germination with C. latifolia seeds at 20 °C in either light or dark treatments after an 8 week incubation period. Seeds of M. media sown onto ½ MS medium resulted in higher germination in all developmental stages (3–5) in dark treatment than OMA and Pa₅. Seeds of P. sanguinea sown onto ½ MS medium resulted in higher overall germination in all developmental stages (3–5) in light and dark incubation compared to OMA and Pa₅. OMA supported the highest asymbiotic germination (100 %) in both light and dark incubation with M. media (only to stage 3) but did not support germination and development with other spp. tested. Caladenia huegelii seeds reached developmental Stage 3 (i.e. germinated), but only on Pa₅ medium and only at a relatively low rate in either light (2.6 %) or dark (2.1 %). Germination was higher and development of seedlings faster overall in all test species in symbiotic compared with asymbiotic media treatments. P. sanguinea seeds demonstrated the best response (among species tested) to asymbiotic germination on ½ MS with 40–53 % of germinated seeds spread over developmental stages 3–5 in light or dark incubation (at 20 °C) respectively. Illumination had no effect on fungal symbiont growth across all species, however incubation temperature treatments (10, 15, 20 and 25 °C) affected fungal growth rate. Growth of the fungal symbionts of C. huegelii, M. media and C. latifolia demonstrated significantly lower activity at 10 °C, but the cumulative radial growth rate of the P. sanguinea fungal symbiont reached 64 cm² after only 2 weeks at all temperatures tested, including 10 °C. The study highlights differences in symbiotic and aysmbiotic germination and early protocorm development in vitro between co-occurring herbaceous terrestrial Australian orchid taxa in response to variations in basal media, temperature and light.     

31 Effects of light and ammonium on growth,ammonium uptake and pigmentation of four porphyra (bangiales,rhodophyta) species native to the northwestern atlantic

“Phytopia: Discovery of the Marine Ecosystem” is an educational CD‐ROM that features a wealth of new images, animations, microscope‐ and satellite‐derived data sets, and multimedia discovery tools. It has received support from NASA and the National Science Foundation and can ordered on‐line through http://www.bigelow.org/phytopia . A pre‐release version of the “Phytopia” was tested by students, educators, and scientists at 34 institutions in Britain, Germany, Russia, and throughout the U.S. This product is designed for use in undergraduate classes; however, our testing has shown that it provides an exciting and interactive learning experience appropriate for Grades 7 and higher. The virtual microscope tool allows the user to view prepared assemblages of plankton at various magnifications, under different epifluorescence conditions, or by scanning electron microscopy. For several species, the user can view movies showing the organism's motility. Some species are featured as three‐dimensional models that can be viewed from any perspective. “Phytopia” also helps users connect ocean primary productivity patterns with environmental factors in several geographic areas. Innovative tools allow investigation of co‐registered temperature, wind, current, nutrient, and ocean color data. This tool is aligned with research efforts to better understand plankton ecology using remotely sensed data.     

A new genus and four new species of Criconematidae (Nematoda) from the Pacific

Summary A new criconematid genus Amphisbaenema is proposed, its type being a new species, A. paradoxiger, from Western Samoa which shows an unusual combination of features in that the outer layer of the female cuticle is broken up into numerous platelets and the female head is rounded without submedian lobes, labial plates or pseudolips; the male has prominent caudal alae and juveniles have longitudinal rows of tubercles over most of the body which is covered by an outer layer of fine backwardly directed spines. Nothocriconema lamellatum (Raski & Golden, 1966) De Grisse, 1967 is transferred to this genus and a second new species, A. amicorum, from Tonga is tentatively assigned to it. Two new Nothocriconema species, N. polynesianum and N. lanxifrons, are also described. ac]19810806     

A comparison of the predatory impacts of an invasive and native crab species using a functional response approach

The European green crab (Carcinus maenas) is invasive on the West coast of North America, but the ecological consequences of this invasion remain poorly understood. Comparative functional response analysis has arisen as a method of elucidating ecological consequences of invasive species by comparing the impact of these species to native analogues. Through comparative functional response experiments of green crabs and native red rock crabs (Cancer productus) we found that green crab predation increased asymptotically (Type II functional response) when fed increasing densities of Pacific oysters (Magallana gigas), while red rock crab predation displayed a sigmoidal (Type III) response. At high oyster densities red rock crabs consume more Pacific oysters than green crabs do, due to their reduced handling time, though green crabs consume more Pacific oysters relative to their size than red rock crabs. However, compared to red rock crabs, green crabs consume more oysters at low prey densities, which implies that they have a larger, potentially destabilizing impact on low densities of Pacific oysters. As green crabs continue to spread across the West coast of North America, Pacific oysters will face increased predation pressure. Our results show the advantage of using functional response analysis to compare density dependent predation between an invasive species and a native species to predict the ecological consequences of invasions.

     

Effect of temperature on photosynthesis-light response and growth of four phytoplankton species isolated from a tidal freshwater river

Three cyanobacteria (Microcystis aeruginosa Kütz. emend. Elenkin, Merismopedia tenuissima Lemmermann, and Oscillatoria sp.) and one diatom (Aulacoseira granulata var. angustissima O. Mull. emend. Simonsen) were isolated from the tidal freshwater Potomac River and maintained at 23° C and 40 μmol photons·m^?2·s^?1 on a 16:8 L:D cycle in unialgal culture. Photosynthetic parameters were determined in nutrient‐replete cultures growing exponentially at 15, 20, 25, and 30° C by incubation with ¹⁴C at six light levels. P ^B_max was strongly correlated with temperature over the entire range for the cyanobacteria and from 15 to 25° C for Aulacoseira, with Q₁₀ ranging from 1.79 to 2.67. The α values demonstrated a less consistent temperature pattern. Photosynthetic parameters indicated an advantage for cyanobacteria at warmer temperatures and in light‐limited water columns. P ^B_max and I_k values were generally lower than comparable literature and field values, whereas α was generally higher, consistent with a somewhat shade acclimated status of our cultures. Specific growth rate (μ), as measured by chlorophyll change, was strongly influenced by temperature in all species. Oscillatoria had the highest μ at all temperatures, joined at lower temperatures by Aulacoseira and at higher temperatures by Microcystis. Values of μ for Aulacoseira were near the low end of the literature range for diatoms consistent with the light‐limited status of the cultures. The cyanobacteria exhibited growth rates similar to those reported in other studies. Q₁₀ for growth ranged from 1.71 for Aulacoseira to 4.16 for Microcystis. Growth rate was highly correlated with P ^B_max for each species and the regression slope coefficients were very similar for three of the species.     

Phytoplankton species and abundance in response to eutrophication in coastal marine mesocosms

In a mesocosm nutrient enrichment experiment the species (orcategories) and abundances of diatoms, dinoflagellates, flagellates,monads and ciliates were identified and counted over a 16-monthperiod. Diatoms and ciliates increased with increasing nutrienttreatment while monads and flagellates, <10 µm in size,did not. By contrast, in the field diatoms sometimes appearedto decrease while small phytoplankton µ10 µm appearedto increase under eutrophic conditions. In the experiment, insome instances, grazing controlled abundances to low levelsin nutrient-enriched treatments. Self-shading by phytoplanktonlimited upper levels of abundance when nutrients were excessive.While nuisance species were occasionally present in variousnutrient treatments, the intensity and frequency of their presencedid not tend to increase with nutrient treatment. Generallyspecies (or categories) did not appear to change with nutrienttreatment.     

中国广东一个小型杯状的斜盖伞新种(英文)

报道了一个采自中国广东省的斜盖伞新种——近杯状斜盖伞Clitopilus subscyphoides。该新种主要特征包括其小型白色的担子果、杯状的菌盖及8–10棱的担孢子,讨论了新种与近似种C.scyphoides和C.peri的差异。模式标本保藏于广东省微生物研究所真菌标本馆。     

A new genus and four new species of Eriophyidae from China (Acari: Eriophyoidea)

One new genus and four new species of eriophyoid mites from Hainan, China are described and illustrated in this paper: Dicoxiseta Wang, Tan & Yang, gen. nov., D. litsea Wang, Tan & Yang, sp. nov. infesting Litsea monopetala(Roxb.) Pers.(Lauraceae), Eriophyes casearius Wang, Yang & Tan, sp. nov. infesting Casearia glomerata Roxb.(Flacourtiaceae), Phyllocoptruta alstonia Wang, Gu & Tan, sp. nov. infesting Alstonia scholaris(L.) R. Br.(Apocynaceae) and Aculus paederius Wang, Gu & Tan, sp. nov. infesting Paederia scandens(Lour.) Merr.(Rubiaceae). Tegolophus artocarpi Keifer, 1977 is newly recorded from China. E. casearius Wang, Yang & Tan, sp. nov. distorts severely new foliage of its host plant. Three species, P. alstonia Wang, Gu & Tan, sp. nov., A. paederius Wang, Gu & Tan, sp. nov. and T. artocarpi, cause rust on the undersurfaces of host plants, while D. litsea Wang, Tan & Yang, sp. nov. is a vagrant on the undersurface of host plant leaves, without visible symptom.     

A new genus and two new species of marine free-living nematodes from the coastal waters of Southern Vietnam

A new genus and two new species of free-living marine nematodes from sediments in the coastal zone of the South China Sea (Vietnam) are described. Cyartonemoides gen. n. morphologically resembles Cyartonema Cobb, 1920, but differs from it in having a well-developed cephalic capsule. Cyartonemoides foetidus gen. n., sp. n. is the type and the only species of the genus. Campylaimus abnormis sp. n. differs from all species of the genus Campylaimus Cobb, 1920 by the shape of the amphidial fovea and shorter lateral fields.     

A new species of Senna (Caesalpiniaceae) from coastal northern Bahia,Brazil

Irwin, Howard S. (Clark Garden, 193 I. U. Willets Road, Albertson, NY 11507) and Rupert C. Barneby (New York Botanical Garden, Bronx, NY 10458-9980). A new species of Senna (Caesalpiniaceae) from coastal northern Bahia, Brazil. Brittonia 37: 192–194. 1985. - Senna (sect. Chamaefistula ser. Laxiflorae) phlebadenia, closely akin to S. australis, but the only known species of the genus with secondary veins of leaflets excurrent into a marginal nectary, is described and illustrated from two collections from the coastal plain of Bahia northeast of Salvador.     

三个乡土树种对Cu、Pb胁迫的生理生态响应

选择三种乡土树种樟树、大头茶和红鳞蒲桃,喷洒含有不同浓度的Cu和Pb溶液,同时设置一个没有喷洒重金属的空白实验.设置的浓度梯度Cu为0 mg·L^-1、50 mg·L^-1、150 mg·L^-1、250 mgL^-1;Pb为0 mg·L^-1、10 mg·L^-1、20 mg·L^-1、30 mg·L^-1.培育期结束后测量三个树种的树高;根、茎、叶的生物量和总生物量;以及叶片生物膜的透性和SOD的活性.结果表明(1)随着重金属浓度的增加,三种乡土树种的高生长和生物量的增加都受到了显著的抑制,浓度越高抑制越明显.相较而言红鳞蒲桃长势较好.(2)随着Cu、Pb浓度的升高,植物叶片的质膜透性变强,受到的伤害增大.Cu250 mg·L^-1下樟树叶片生物膜受到伤害最大,而在Pb30 mg·L^-1下大头茶叶片质膜受到伤害最大.(3)SOD活性在Cu的胁迫下呈现随着浓度的增加,先升高后下降的规律,但大头茶的SOD活性在一直增加.(4)在Pb的胁迫下,SOD的活性随胁迫的浓度的升高一直下降,只有红鳞蒲桃在后期表现出了增长的趋势.