转基因油菜生产的农业环境安全

根据转基因油菜的研究和环境释放现状,对我国转基因油菜可能存在的农业环境安全性问题进行风险分析,认为中国转基因油菜的基因扩散风险高于其他作物,对农业环境安全带来的隐患不容忽视。     

转Bt基因作物对丛枝菌根真菌的影响研究进展

在过去的十年里，世界范围内转基因作物尤其是抗虫性转Bt基因作物的品种和种植面积迅速增加。同时，转Bt基因作物的环境安全性评价问题成为人们关注和研究的热点。丛枝菌根真菌（AMF）是生态系统中普遍存在的土壤微生物，能与绝大多数植物种类形成共生关系，在农业生态系统中起重要作用。转Bt基因作物环境释放后，其与AMF问的共生关系是否受所转入Bt基因的影响，以及影响机制需要及时研究。为此，综述了转Bt基因作物与AMF共生特征方面的研究进展，并根据Bt毒素发生的空间和时间规律提出了危害机制以及转Bt基因植物的规模化种植将降低农田系统中的AMF的生物多样性的观点。     

转codA基因的耐盐碱水稻对大鼠生理代谢的影响及外源基因的水平转移

实验选用32只SD大鼠随机分成2组，分别饲喂含30％转codA基因水稻（Oryza sativa L．）和含30％非转基因水稻的大鼠配合饲料，2组饲料其它成分相同，各项营养指标和卫生指标均无显著差异，连续饲喂30d。结果发现，实验组大鼠体增重与对照组相比无显著差异（P〉0．05），血清中生长激素（growth hormone，GH）、胰岛素（insulin）、胰高血糖素（glucagon）、甲状腺素（triiodothyroxine T3，tetraiodothyroxine T4）、促甲状腺素（thyroid—stimulating hormone，TSH）、尿素氮（serum urea nitrogen，SUN）、葡萄糖（glucose）、谷丙转氨酶（glutamyl tranpeptidase，GPT）和血清总胆固醇（total cholesterol）等与对照组相比无显著差异（P〉0．05）。同时，分析大鼠的血液、肌肉、肝脏、胰脏、肾脏、胃及肠道内容物PCR扩增水稻内源基因SPS和外源基因codA的特异性片段在大鼠体内的转移情况，结果表明，用含转codA基因水稻的饲料饲喂大鼠，大鼠血液及各组织器官中没有发现转基因水稻内源基因和外源基因片段，而在大鼠胃、肠道内容物中发现了转基因水稻的内源基因和外源基因的片段，说明短期内转基因水稻的内源和外源基冈没有发生遗传转移。     

花青素调节基因Lc对转基因烟草和矮牵牛花色的影响

利用PCR的方法从油菜(Brassica napus)基因组中扩增得到花瓣特异性启动子XY355，将XY355与玉米花青素调节基因Lc融合构建植物表达载体pXY60。用冻融法将pXY60转入根癌农杆菌（Agrobacterium tumefaciens）LBA4404，然后以烟草（Nicotiana tabaccum L.）和矮牵牛（Petunia hybrida）的叶盘为外植体，通过根癌农杆菌介导法进行遗传转化。对再生植株的PCR检测证明外源基因已经整合到转基因烟草和矮牵牛的基因组中。对转基因烟草和矮牵牛的表型进行观察：转Lc基因烟草的花色由浅红变成了红色，转Lc基因矮牵牛的花色由白色变成了浅紫色。     

我国水稻产业发展的期望与守望

中国生物安全网于2009年10月22日发布了“2009年第二批农业转基因生物安全证书批准清单”,在清单中审批编号分别为“农基安证字（2009）第072号”和“农基安证字（2009）第073号”,由华中农业大学张启发教授及其同事申报的“转crylAb／crylAc基因抗虫水稻华恢1号”和“转crylAb／crylAc基因抗虫水稻Bt汕优63”的两个水稻品种已获得安全证书,     

我国转基因水稻的环境生物安全评价及其关键问题分析

转基因水稻的商品化种植可能带来潜在的环境生物安全问题,例如：转基因对非靶标生物的影响,外源转基因逃逸及其可能带来的生态后果,转基因植物对生物多样性的影响,以及转基因对土壤微生物群落的影响等。对于转基因水稻的大规模种植进行科学的环境安全评价,有利于其可持续生产和安全利用。从我国的水稻生态系统和水稻种植方式的实际情况出发,结合我国可能进行商品化种植的转基因水稻种类,作者对转基因水稻品种的环境释放和商品化种植可能导致的潜在环境生物安全问题进行了科学和理性的分析。根据风险评价的原则（风险% = 危害性 × 发生概率）,本文特别对抗病、虫和抗除草剂转基因水稻的商品化种植可能带来的直接和间接影响进行了分析和讨论,希望能为转基因水稻商品化种植的决策提供参考,并为转基因水稻的环境安全性评价提供科学依据。     

土壤真菌群落和潜在功能对施加外源Bt毒素的响应

【目的】转Bt基因植物和Bt菌生物农药释放的Bt毒素是一类具有生物毒性的潜在环境外源污染物，Bt毒素环境行为和生态效应是转基因植物和植物用转基因微生物安全风险评价的重要内容，但是外源Bt毒素对土壤真菌群落和潜在功能的影响还不清楚。【结果】本研究发现，Bt毒素施加量和培养时间均可以显著影响土壤真菌群落组成，且随着Bt毒素施加量增加和土壤培养时间延长，土壤真菌群落差异性逐渐变大。施加Bt毒素提高了土壤真菌群落香农指数和关联网络的负相关性比例及模块数，因而没有对土壤真菌群落的多样性和稳定性产生负面影响。【结论】上述结果表明，评估Bt毒素的环境行为及微生态效应要关注Bt毒素施加量及其长期影响。随着Bt毒素施加量增加，Phymatotrichopsis、Homalogastra、Geosmithia和Apiotrichum等真菌以及参与蛋白质降解、碳素代谢和磷素代谢的功能基因编码酶相对丰度显著升高，推测上述真菌物种和潜在功能参与了Bt毒素在土壤中的降解和转化过程。研究结果为转Bt基因植物、Bt重组菌生物农药以及Bt毒素的生态安全风险评价提供了科学参考和理论依据。     

转基因植物的生态安全性风险

转基因植物的应用在对农业生产带来重大变革的同时,其安全性风险备受关注。本文重点论述了转基因植物的生态安全性风险,即转基因植物的使用带来的直接或间接的生态影响,包括：目标害虫对转基因植物的抗性,转基因植物对非目标害虫的毒性及其对寄主嗜好性、有益生物及天敌的安全性、生物多样性及生态系统结构的影响;基因漂移及杂草化问题及应用转基因作物后植保费用的变更等。针对这些关键问题,定量风险评估和制定风险预防与治理策略具有重要意义。     

反义PEP基因调控油菜籽粒蛋白质/油脂含量比率的研究

利用根癌农杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍ ｔｕｍｅｆａｃｉｅｎｓ）ＥＨＡ１０１携带反义ＰＥＰ基因和卡那霉素,潮霉素抗性基因,采用共培养法转化甘蓝型油菜（ＢｒａｓｓｉｃａｎａｐｕｓＬ．）浙油７５８和浙优油１号的下胚轴,通过组织培养获得了能在培养基上生长的油菜转基因植株。经ＧＵＳ组织化学染色及ＰＣＲ扩增检测,证明外源基因已插入油菜基因组并得到表达。浙油７５８转基因植株Ｔ１代种子平均含油量比对照提６．     

安全之源 绿色屏障

农业环境是农产品安全的源头。农业部环境监测总站（AEMC）作为全国农业环境监测网的网头单位．和全国33个省级和800多个重点地、县级农业环境监测站一起，肩负着保护农业环境的重任。30多年来。农业部环境监测总站（AEMC）在全国农业环境质量调查、生态农业、生物多样性、农业环境信息平台建设、农业环境污染事故处理等领域开展了大量卓有成效的工作，     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.