江苏省水生蔬菜优良种质资源的 保护及开发利用现状与建议

对江苏省水生蔬菜的生产、优良种质资源的保护和开发利用现状进行了调查研究。分析了江苏水生蔬菜生产在全国的特色和优势，以及在江苏农业生产中的重要性；指出了因城市建设征用水生蔬菜生产用地、生产中对选留种重视不够和对优异种质资源的研究利用不深入等导致种质资源流失、病虫害多发及品种退化等问题，提出了建立相关规章制度、建设种质资源保存圃、应用植物组织培养技术等保存优良种质的措施，以及加强种质资源优良性状研究和开发利用的建议。     

Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.     

不同氮磷钾施肥量对烤烟农艺性状及养分吸收的影响

研究氮磷钾用量对烟草生长和叶片养分吸收的影响,大田试验结果表明,不同水平的N、P、K施肥量明显影响烟株的长势,影响程度N>K>P,综合考虑产量和上等烟比例,以施肥量N 112.5 kg/hm2、P2O5112.46 kg/hm2、K2O 269.84 kg/hm2的N2P2K2处理最好,某种元素不足或过量都会降低上等烟比例。施用适量的氮有利于烤烟中N和K的吸收,而过量50%的N3水平的氮使烟草钾含量降低了11%。磷浓度过高或过低都会降低N和K的积累。增施K肥有利于N和K的积累,其中钾含量最高增长幅度可达37%。随着氮用量增加,上等级烟氮肥农学利用率呈直线下降的趋势,而磷、钾农学利用率在一定氮磷钾用量范围内增加。     

农业专家系统生成工具AEST 3.0

为使农业领域专家的知识和经验迅速推广，以指导农民科学种田，本研究在Windows98平台上，利用面向对象技术及VC＋＋语言设计并实现了基于呼数学模型的专家专家系统生成工具AEST3．0（Agriculture Expert System Tool)，介绍了面向对象的知识库与模型库以及继承搜索式不确定通用推理机的设计与实现，并给出了AEST的一个运行实例。     

普那菊苣引种栽培试验

针对石羊河下游民勤绿洲地下水资源严重超采,地下水位持续快速下降的现状,以及所引起的生态环境效应,提出了恢复地下水位生态需水量的概念和计算方法,并且预测出2000—2019各年恢复地下水位生态需水量。根据民勤绿洲的具体特点提出了恢复持续下降的地下水位、改善和恢复生态环境的一些可行措施。     

Resveratrol induces apoptosis through ROS-dependent mitochondria pathway in HT-29 human colorectal carcinoma cells

trans-Resveratrol is a polyphenol found in blueberries, grapes, and wine with cancer chemopreventive properties. The low bioavailability of this compound enhances its concentration in the luminal content and becomes a potential chemopreventive agent against colon cancer. In the present study, the antiproliferative and pro-apoptotic effects on the human colorectal carcinoma HT-29 cells as well as the mechanisms underlying these effects were examined. Proliferation, cytotoxicity, and apoptosis were measured by fluorescence-based techniques. Studies of dose-dependent effects of trans-resveratrol showed antiproliferative activity with an EC 50 value of 78.9 +/- 5.4 microM. Caspase-3 was activated in a dose-dependent manner after incubation for 24 h giving an EC 50 value of 276.1 +/- 1.7 microM. Apoptosis was also confirmed with microscopic observation of changes in membrane permeability and detection of DNA fragmentation. The activity of trans-resveratrol on the mitochondria apoptosis pathway was evidenced by the production of superoxide anions in the mitochondria of cells undergoing apoptosis. In conclusion, trans-resveratrol inhibits cell proliferation without cytotoxicity and induces apoptosis in HT-29. Results of the present study provide evidence demonstrating the antitumor effect of trans-resveratrol via a ROS-dependent apoptosis pathway in colorectal carcinoma.     

Effect of top-dressed potassium fertilization on the yield and quality of cucumber

The current study aimed to evaluate the effect of top-dressed potassium (K) application on the production of hybrid cucumber “Sapphire.” The experimental design was a randomized complete block, with five blocks of 0.80 × 0.40 m² each and eight replicate plants per block. The five fertilization rates of K used were 0, 45, 90, 135, and 180 kg K₂O ha^?1. Data collection consisted of the estimation of fruit diameter, fruits length, fruit fresh and dry weights, the number of fruits per plant, and the weight of fruits per plant. The number of fruits per hectare and the fruit fresh weight per hectare were calculated. Fruit tissue was analyzed for determination of macronutrient concentrations, pH, titratable acidity, soluble solids, sugar contents, and protein content. The data were statistically analyzed using regression analysis and analysis of variance (ANOVA). There was a significant effect of the fertilization rate of K on fruit diameter, fruit fresh and dry weights, macronutrients concentrations in fruits, titratable acidity, soluble solids, and reducing sugars. A quadratic equation was adjusted for the number of fruits per plant and per hectare; fruit yield per plant and per hectare, with maximum top-dressing doses, was estimated to be between 60 and 95 kg K₂O ha^?1. A linear increase was obtained in the pH. An increase in the K fertilization rate caused a linear decrease in the fruit length.     

Long-term changes in concentration and deposition of atmospheric mercury over Scandinavia

Samples for measurements of total gaseous mercury (Hg) in air have been collected since 1980 in south-western part of Scandinavia. A collection program for precipitation samples used to determine changes in depositional fluxes of total Hg has been in operation since 1987. A comparison of today's total gaseous Hg levels in air and the total Hg concentrations in precipitation with the ones found earlier, shows a clear decrease with time. At the Swedish west-coast, yearly average air concentrations and median levels of 3.3 and 3.1 (1980–1984), 3.2 and 2.8 (1985–1989), and 2.7 and 2.6 ng Hg/m³ (1990–1992), respectively, were found. Increased average and median winter concentrations were always found, with levels at 3.7 and 3.4, 3.7 and 3.3, and 3.0 and 2.7 ng Hg/m³ for the respective time period. Higher winter values were expected due to increased anthropogenic emissions and changes in the mixing height of the atmosphere. The corresponding total wet deposition rates decreased from 27 (1987–1989) to 10 μg Hg/m² yr. (1990–1992). A finding of special interest was the decreased number of episodic events of high total gaseous Hg levels in air, from 1990 and further on. In addition, the frequency distribution of the concentrations of Hg in air seems to be different for these years compared to the other two time periods. A frequency distribution of air concentrations of Hg more resembling a normal distribution was found for the years 1990 to 1992. The decrease of the atmospheric burden of total gaseous Hg and deposition of total Hg are most probably connected to lower emissions in source areas on the European continent. It seems logical to state that the problem of high Hg depositional fluxes to Scandinavia, is best solved by abatement strategies on the regional scale.     

Mercury in fish in Swedish lakes — Linkages to domestic and European sources of emission

The work deals primarily with data from 894 Swedish lakes. The following parameters are discussed: Hg- and Se-concentrations and Hg-quantity in the mor layer reflecting the atmospheric deposition of Hg and Se-, Hg- and S-emissions deposition from Swedish and continental sources, precipitation, Hg in pike, lake area, lake mean depth, pH, color, alkalinity, hardness, S and chloride in lake water. The results are focused on geographical variations and statistical correlations for the Hg-content in 1-kg pike (=FHg), and on computer simulations to get insights and data on the linkages between various historical Hg-emissions and FHg. Selected results: Increased FHg-values may be attributed to atmospheric emissions of Hg and to acid rain. Southern Sweden is significantly influenced by continental Hg-emissions. East Germany, Great Britain, West Germany and Poland seem to have contributed with the largest foreign Hg-amounts in the Swedish mor layer and, at the end, to increased Hg-concentrations in Swedish fish. We have calculated that there are about 10 300 Swedish lakes with FHg > 1 mg Hg kg^?1 (= the Swedish blacklisting limit). What would happen with FHg if atmospheric depositions of Hg and S were significantly reduced? Reductions of S would be beneficial primarily for lakes in S. Sweden. About 50% of the elevated levels of Hg in Swedish pike in the 1980s may be linked to Swedish Hg-emissions during the last 100 yr, about 10 to 15% could be attributed to foreign Hg-emissions and 35 to 40% to acid rain. There is a long lag phase between emission reduction and reduction of FHg. The known, major Swedish emissions of Hg have already been significantly reduced, but new point sources of Hg have appeared. There has been a significant change in the character of the Hg-emissions during the last decades. High FHg-values in fish in Swedish lakes will be a major environmental problem for decades to come.     

<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L. agg. in the Carpathian Basin: a blessing or a curse?

Helianthus tuberosus agg., an herbaceous perennial plant from the Asteraceae family, is native to North America and was introduced as a crop to Europe in the seventeenth century. The status of this plant has been rather controversial in the Carpathian Basin. This paper reviews its taxonomy, chorology, and ethnobotany in this region, using data obtained from herbarium specimens, ethnobotanical surveys performed in Transylvania, and data published earlier, documenting the invasive features of the plant since the beginning of the nineteenth century. Our results suggest that (1) Helianthus tuberosus agg. has been present in the Carpathian Basin from the nineteenth century, (2) its taxonomy is problematic since the first part of the nineteenth century; (3) ethnobotanical surveys confirmed that the plant’s tuber has been locally used mostly as a food in Transylvania, collected from cultivation. Overall, Helianthus tuberosus agg. is both a ‘blessing and a curse’ at the same time, it is a valuable crop with beneficial nutritional value, and also an environmentally dangerous invasive element for the diversity of the flora of the Carpathian Basin.