冰冻灾害前后矿区废弃地栾树杜英混交林生态系统养分含量的比较

对冰冻灾害前后湖南湘潭锰矿矿区废弃地的栾树、杜英混交林生态系统的地表水、土壤、林木及死地被物的养分含量进行对比研究.结果表明:冰冻灾害后,林地地表水的pH值、电导率、溶解氧、K、Ca、Mg含量明显减少,Zn、Mn、Pb含量显著增加;林内土壤含水量、全P、全K含量显著增加,速效N、速效P、速效K含量明显减少,微量元素Cu、Pb、Co含量增加,Fe、Zn、Mn、Cd、Ni含量减少;林木枝、叶、干中含水量均显著减少,树干中N、P、Ca、Mg、Cu、Zn、Mn、Cd、Ni、Pb、Co含量增加,树枝和树叶中P、K、Mg减少,而Cu、Fe、Zn、Mn、Cd、Ni、Pb、Co含量却增加;林地上的死地被物中K、Mg在各组分(未分解、半分解、已分解)含量降低,Cu、Fe、Mn、Ni、Co含量增加.可为突发性自然干扰对植物生命活动的影响及抗御机理的研究提供基础数据.     

池塘主养草鱼种高产试验

在３００５ｍ＾２的池塘里,高密度培养大规格草鱼种,且塔养鲢,鳙,鲤种。采取的技术措施是：草鱼种入池先喂芜萍,２０天后改喂浮萍并驯喂粗蛋白含量较高的小颗粒配饵。草鱼种长到１０ｃｍ后,改喂粗蛋白含量较低的配饵;定期注入新水,增氧,泼洒药物,投喂药饵,高温季节,使池水保持长流水。结果：共产草鱼种５０３２ｋｇ,平均规格８０．１ｇ;鲢鳙鱼种２６６０．６ｋｇ,鲤种５３６．３ｋｇ,纯利４８９２８．６元,投入产出     

铬盐对鲤生长和饲料转化率的影响

以０．５ｍｇ／ｋｇ铬盐饲料饲喂１龄鲤６５ｄ和３月龄鲤３０ｄ,相对生长率分别提高１３．７９％和２０．６９％饲料转化率提高２１．８３％和２６．０％。表明铬盐有促进鱼类生长作用和提高饲料转化率的效应,而铬盐对鱼体营养成分的作用不明显。但铬盐对对高血糖症鱼的作用是低剂量各（２．５μｇ／ｋｇ体重）使血糖明显下降,高剂量（６０μｇ／ｋｇ体重）则使血糖明显升高;铬盐含量０．５ｍｇ／ｋｇ饲料使高血糖症鱼的血糖下降     

Phenotypic variation in a core collection of common bean (Phaseolus vulgaris L.) in the Netherlands

Forty accessions, forming a core collection of mainly bush type of the common bean (Phaseolus vulgaris L.) germplasm in the Netherlands, were evaluated for 14 qualitative and quantitative traits at the Agricultural University, Wageningen (WAU), the Netherlands in 1992. These and an additional 117 Dutch accessions, mainly collected in private home gardens, were also evaluated for phaseolin seed protein pattern, and morphological and agronomic traits at the International Center for Tropical Agriculture (CIAT, Spanish acronym), Cali, Columbia between 1987 and 1997. Multivariate and principal component analyses at both WAU and CIAT indicated existence of one large group with no discernable patterns among Dutch common bean collections of landraces, garden forms and cultivars. However, when phaseolin, an evolutionary, biochemical marker, was used as an initial classification criterion followed by use of morphological markers, the two major gene pools; Andean and Middle American with two races in each (Chile and Nueva Granada in Andean, and Durango and Mesoamerica in Middle American) were identified. The Andean gene pool was predominant (136 of 157 accessions), especially the race Nueva Granada (126 accessions) characterized by the bush determinate growth habit type I and T phaseolin. The new core collection comprised 31 accessions. Bean races Chile, Durango, and Mesoamerica were represented by 10, 7, and 14 accessions, respectively. Of the 9 French or snap bean accessions six possessed characteristics of race Mesoamerica and three belonged to Durango race. Occurrence of these and a large number of other recombinants strongly suggested considerable hybridization and gene exchange between Andean and Middle American gene pools, thus blurring the natural boundaries and forming a large single group of common bean germplasm in the Netherlands. The inter-gene-pool recombinants of both dry and French beans should be of special interest to breeders for use as bridging-parents for development of broad-based populations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Study on Optimum Operating Parameters of Air-WaterBackwashing of Common Sand Filter

In this paper, the optimum operating parameters for air-water backwashing of common sand filter with three different backwashing manners are chosen by single factor optimization and multiple cross experiments. It is concluded that the three-phase combined backwashing manner is the best one.     

Facilitating User Participation in Irrigation Management

This paper examines various factors which contribute to performance of water user associations. The capability of collective organizations such as WUAs to develop appropriate rules and to enforce them while keeping the level of conflict low is considered to be the core of organizational performance. We focus on the processes in collective organizations with greater attention to costs of working together. Four factors representing benefits and costs, the rights held by the WUAs, magnitude of expected benefits, external assistance received and leadership explain most of the differences in performance. The prospect of benefits is a necessary condition for individuals to act collectively. But it is not sufficient. Expected organizational costs need to be low. The prospect of costs being low or being absorbed by one or more individuals – either external agents or internal leaders – provides an encouraging environment. Effective internal leadership appears to be essential as it can lead to greater congruence in interests and greater possibility of mutual assurances which are critical for collective action.     

无芒山羊草细胞质对小麦性状影响的研究

用含有无芒山羊草细胞质的１０个稳定普通小麦异质系为材料,调查了该细胞质对供试小麦雄性育性,生长势,生育期和主要农艺性状的影响以及其异质小麦不育系易恢性的特性,同时对该细胞质在杂种小麦研究中的应用价值作了探讨。     

N·P·K平衡施肥对紫云英产量的影响

经过几年多点试验,发现平衡施肥对提高紫云英鲜草和种子产量均有显著增产效果。施N·P·K鲜草量分别比施N、NP和NK平均增产42．3％,14.9％和25.6％;种子产量分别平均增产36．3％,14％,22％,并且发现施用K肥能增强抗性。     

小麦株高的QTL分析

【目的】研究控制小麦株高的数量性状位点(QTL)。【方法】利用SSR和AFLP分子标记构建连锁图谱,在3种不同试验环境(2003~2004年北京、2004~2005年北京和河南安阳)下分析百农64×京双16组合的218个F2:3株系群体的株高。【结果】构建了由158个分子标记(100个SSR标记和58个AFLP标记)位点组成的遗传连锁图谱,覆盖了除1D连锁群外小麦全基因组的3 114 cM;检测到3个控制株高的QTL,分别位于2B、4D和6A染色体上,贡献率分别为7.3%~11.5%,7.4%~12.9%和5.7%~11.3%。【结论】3个株高QTL位点在不同环境下表现稳定,其紧密连锁的分子标记可用于矮秆、半矮秆小麦的标记辅助育种。     

普通小麦溶剂保持力品种间差异及低溶剂保持力种质资源筛选

以283份国内外小麦品种资源为试验材料,利用微量溶剂保持力（SRC）方法对其水SRC、蔗糖SRC、碳酸钠SRC和乳酸SRC进行了测定,初步分析了不同SRC存品种间的差异情况以及4种SRC之间的相互关系。水SRC主要分布在85％～95％,占材料总数的66．9％;碳酸钠SRC主要分布在100％～110％,占材料总数的48．8％;乳酸SRC土安分布在90％～105％,占材料总数的80．6％;蔗糖SRC主要分布在125％～140％,占材料总数的72．0％。4种SRC品种间差异皆达极显著水平。SRC的相关分析显示,4种SRC间极显著正相关,其中水SRC与乳酸SRC的相关系数最人,为0．907,而与蔗糖SRC的相关系数最小,仅为0．177。在简单相关分析的摹础上,利用多元同归线性模型预测了水SRC（Y）与碳酸钠SRC（x1）、乳酸SRC（x2）和蔗糖SRC（x3）之间的回归天系,得到方程Y=18．618＋0．320x,＋0．473x2-0．066x3。同时根据SRC值的分布情况,初步筛选了一批SRC表现较低的小麦品种资源,这些资源可作为低SRC小麦品种选育的中间材料加以利用。