基因型和环境及其互作对糜子主要农艺性状的影响

为了进一步了解基因型、环境及其互作对糜子主要农艺性状的影响,运用联合方差和AMMI模型对6个糜子新品种(粳性)在11个不同环境试点的生育期、株高、主茎节数、主穗长、穗粒重、千粒重和产量等7个主要农艺性状的表现及其品种稳定性与适应性进行了研究。结果表明,糜子主要农艺性状在不同基因型以及环境之间存在极显著差异,其中基因型对主茎节数、环境对株高、基因型与环境互作对穗粒重的影响较大。各品种7个农艺性状指标的变异系数中,最大的是产量,达42.72%,其次是穗粒重和株高,分别为37.90%和26.74%,变异系数最小的是生育期,为14.89%。各试点中产量最高的是甘9133-1-3-4-1,品种稳定性最好的是榆糜3号(CK)。宁夏彭阳和陕西延安试点产量较高,变异程度较小,对品种鉴别力较好。     

长江中游某矿区水体和沉积物重金属来源解析及分布特征和生态风险评估

为探究长江中游沿江某矿区周边水-沉积物重金属分布特征、潜在风险及其来源,本研究以江西省北部某矿区周边水体及其沉积物中7种重金属(As、Cd、Cr、Cu、Hg、Pb和Zn)为研究对象,通过多点采样分析其在地表水-沉积物系统中的污染特征,并运用单因子评价指数和地累积指数(I_geo)分别对地表水和沉积物中所含重金属进行风险评价,最后通过正定矩阵因子分析(Positive definite matrix factorization,PMF)模型解析沉积物中重金属来源。结果表明：受酸性矿山废水直排影响,该地区地表水和沉积物酸化严重,pH最低分别为2.12和2.62。水体和沉积物中,以Cu、Zn和Cd超标较为严重,水体中分别为0.001～46.96、0.01～122.90、ND～64.97 mg·L^-1,沉积物中分别为21.30～1 840.61、54.20～1 487.55、0.04～18.73 mg·kg^-1,其中以Cd点位超标率最高(68.97%)。风险评价结果表明,超过50%的点位受到Cu和Cd的污染,属于重度风险等级,且多...     

水稻品种与水稻细菌性条斑病菌的互作机制

水稻叶片接种3d后，水稻细菌性条斑病菌开始在叶片上大量增殖；接种10d后，病菌数量开始保持相对的稳定，但感病品种上的菌量比抗病品种上的菌量在10倍左右，病斑在接种后第3d开始出现，接种10d以后，病斑在感病品种上能继续快速发展，而在抗病品种上开始受到抑制，通过对抗病和感病品种叶片上的气孔观测发现，感病品种的气孔密度和气孔长度一般都较抗病品种大，相关分析表明，气孔长度理发师品种抗性相关。接种后对PAL酶的活性测定结果表明，PAL酶的活性与品种抗性呈负相关关系。     

陆地棉重组近交系产量及其构成因素的QTL分析

利用爱字棉1517×德州047重组近交系(recombinant inbred lines, RIL)中G6群体构建的SSR遗传连锁图谱及基于混合线性模型的复合区间作图法对QTL进行定位,并对主效QTL,加性×加性上位性QTL及与环境互作效应进行分析,为利用分子聚合方法提高产量提供理论依据。对2006年、2008年以及2009年的产量性状进行分离分析,检测到24个不同年份的主效QTL,其中相关于单株籽棉、单株皮棉、衣分、子指以及单株铃数的分别检测到1个不同年份稳定存在的主效QTL;对3年的产量性状作环境因子联合分析,检测到14个主效QTL,其中6个与环境互作,检测到20对加加上位性QTL,其中7对与环境互作。不同年份检测的稳定且受环境影响小或不受环境影响的与近处标记紧密连锁的主效QTL可用于分子标记辅助选择,以提高育种的效率。     

重金属离子相互作用对Cu在鲫鱼组织中积累的影响

研究了重金属离子相互作用对其在鲫鱼组织中积累的影响,结果表明: 混合重金属离子相互作用对Cu在鲫鱼组织中积累的影响与离子的种类、数量及组织的类型有关.随着重金属离子种类的增加,相互作用对其积累的影响变得显著,Cu离子在鱼脑和肝脏中的积累浓度升高 ,在鳃中的积累降低,在肌肉中的积累无影响.重金属离子相互作用不会改变Cu在鲫鱼组织中的分布规律,Cu在鲫鱼组织中的积累顺序为肝脏>鱼鳃>鱼脑>肌肉.     

密封泵中无轴承永磁同步电动机的试验研究

为解决密封泵系统中泵体的密封性问题,提出采用无轴承电动机替代传统电动机构成新型无轴承密封泵方案,研制无轴承电动机成为其关键.阐述了无轴承密封泵中永磁型无轴承电动机转子悬浮原理,并给出电磁转矩和径向悬浮力数学模型.根据无轴承永磁同步电动机控制系统功能框图,构建无轴承永磁同步电动机数字控制系统,为了使控制系统软件与硬件之间互相配合,设计并使用人机交互界面对无轴承永磁同步电动机控制系统中转速、PID控制器等参数进行实时在线调试和控制.样机试验结果表明:使用人机交互界面进行试验调试,能够快速地达到预期目标,转子转速为1 200 r／min,转子轴心在平衡位置中心(0,0)附近振动,径向偏心位移振动幅值控制在50 μm范围之内,满足对无轴承永磁同步电动机数字控制系统进行实时在线调试和控制的要求,对无轴承密封泵的研制与应用具有重要的理论意义和实用价值.     

苦瓜主要经济性状的遗传及其与环境互作效应

 利用加性-显性与环境互作遗传模型, 分析了7个苦瓜亲本及其21个F1代在春、秋两个栽培 季节8个经济性状的数据, 估算了各项遗传方差分量。结果表明, 单株前期产量(单株前产) 、单瓜质量、果实纵径、果实横径、果肉厚和果形指数等6 个性状主要由加性效应控制, 加性方差的比率分别为45.2%、70.7%、89.4%、38.1%、41.2%和22.0% , 均达极显著水平; 单株产量和单株结果数则以加性×环境效应占优势(加性×环境方差的比率分别为24.5%和38.1% ) 。除单株结果数外, 其余性状的普通狭义遗传率和普通广义遗传率均达到极显著水平; 单株结果数的互作狭义和互作广义遗传率最高, 也达到了极显著水平。     

Investigating the mechanisms for the opposing pH relationships of fungal and bacterial growth in soil

Soil pH is one of the most influential variables in soil, and is a powerful factor in influencing the size, activity and community structure of the soil microbial community. It was previously shown in a century old artificial pH gradient in an arable soil (pH 4.0-8.3) that bacterial growth is positively related to pH, while fungal growth increases with decreasing pH. In an attempt to elucidate some of the mechanisms for this, plant material that especially promotes fungal growth (straw) or bacterial growth (alfalfa) was added to soil samples of the pH gradient in 5-day laboratory incubation experiments. Also, bacterial growth was specifically inhibited by applying a selective bacterial growth inhibitor (bronopol) along the entire pH gradient to investigate if competitive interaction caused the shift in the decomposer community along the gradient. Straw benefited fungal growth relatively more than bacterial, and vice versa for alfalfa. The general pattern of a shift in fungal:bacterial growth with pH was, however, unaffected by substrate additions, indicating that lack of a suitable substrate was not the cause of the pH effect on the microbial community. In response to the bacterial growth inhibition by bronopol, there was stimulation of fungal growth up to pH 7, but not beyond, both for alfalfa and straw addition. However, the accumulation of ergosterol (an indicator of fungal biomass) during the incubation period after adding alfalfa increased at all pHs, indicating that fungal growth had been high at some time during the 5-day incubation following joint addition of alfalfa and bronopol. This was corroborated in a time-series experiment. In conclusion, the low fungal growth at high pH in an arable soil was caused to a large extent by bacterial competition, and not substrate limitation.     

受土壤类型和金属负荷量影响的重金属形态分布

Two series of soil subsamples, by spiking copper(Cu),lead(Pb),zinc(Zn)and cadmium(Cd)in an orthogonal design,were prepared using red soil and brown soil,respectively.The results indicated that heavy metal fractions in these soil subsamples depended not only on soil types,but also on metal loading quantity as well as on interactions among metals in soil.Lead and Cu in red soil appeared mostly in weakly specifically adsorbed(WSA),Fe and Mn oxides bound(OX),and residual(RES)fractions.Zine cxisted in all fractions except organic bound one,and Cd was major in water soluble plus exchangeable(SE)one.Different from the results of red soil,Pb and Cu was present in brown soil in all fractions except organic one,but over 75% of Zn and 90% of Cd existed only in SE fraction.Meanwhile,SE fraction for any metal in red soil was lower than that in brown soil and WSA and OX fractions were higher.It is in agreernent with low cation exchange capacity and large amounts of metal oxides included in red soil.Metal fractions in soil,especially for water soluble plus exchangeable one ,were obviously influenced by other coexisting metals.The SE fraction of heavy metals increased with increasing loading amounts of metals in red soil but not obviously in brown soil,which suggest that metal availability be easily affected by their total amounts spiked in red soil.In addition,more metals in red soil were extracted with 0.20 mol L^-1 NH4Cl（pH5.40）than that with 1.0 mol L^-1 Mg(NO3)2(pH7.0),but the reverse happened in brown soil,implicating significantly different mechanisms of metal desorption from red soil and brown soil.     

伴矿景天和鹅掌柴间作系统中根系相互作用对植物生长和镉锌吸收的影响

为明确不同物种根系间的相互作用对植物生长和重金属元素吸收的影响,以Cd、Zn超积累植物伴矿景天与花卉植物鹅掌柴为材料,研究二者根系相互作用及对植物生长和Cd、Zn的影响。结果发现,二者根系具有相互抑制生长的作用。单作条件下伴矿景天的Cd、Zn吸收量最高,分别达0.812、19.6 mg/盆;较单作相比,无分隔间作条件下伴矿景天对土壤Cd、Zn吸收降低分别达30.0%和30.6%。两种植物根系改变了土壤养分性质,对土壤钾和磷的利用分别具有竞争和互补作用,但其有效态含量并未降低到亏缺水平,养分竞争可能不是两种植物根系相互作用的主要因素。水培试验表明鹅掌柴根系分泌物对伴矿景天的生长和Cd吸收具有抑制作用。