几种裸子植物胚乳愈伤组织的诱导

取裸子植物未成熟胚乳作为外植体，在改良MS、添加不同种类激素和不同浓度配比的培养基上．分别予以热激、光培养、暗培养和刻伤胚乳等多种处理进行培养．结果表明：刻伤胚乳和适时暗培养有利于愈伤组织发生；经过25～30d的培养，在ρ（NAA）＝0．5～0．75mg／L、ρ（2，4－D）＝0．2～0．5mg／L、蔗糖浓度5％的培养基上，油松、白皮松、青、华北落叶松以附加ρ（KT）1．0～2．0mg／L以及白、侧柏在BA与KT配合使用的培养基上，热激后暗培养，愈伤组织诱导频率可达86．4％．     

生长调节剂对春玉米氮素积累、转运及籽粒蛋白质含量的影响

为探讨生长调节剂对玉米的影响,文章通过不同生长调节剂(主要成分为羧甲基壳聚糖)处理玉米,研究了生长调节剂对春玉米功能叶片、茎杆、籽粒中氮素含量的变化。结果表明,不同配方的生长调节剂能够促进春玉米功能叶中全氮、蛋白氮的转运;提高春玉米茎秆中氮素的转运量以及玉米的产量;加速籽粒中蛋白质的积累,从而提高玉米的品质。并以施生长调节剂配方2 吐温80(PGR2)的配方效果最好。实验中应用的生长调节剂是一种有效的促进玉米氮白质积累的生长调节剂。     

除草剂对优质小麦品质和旗叶保护酶的调控效应

通过田间试验研究了4种除草剂在正常剂量下对2个优质小麦品种品质性状、蛋白质组分和旗叶保护酶系的影响.结果表明,整个籽粒灌浆过程中,2,4-D丁酯处理使籽粒蛋白质含量一直较高,世玛处理在灌浆前中期籽粒蛋白质含量较高,但灌浆末期籽粒蛋白质含量最低,巨星和骠马处理影响较小.2,4-D丁酯处理使收获时籽粒蛋白质含量及组分最高,湿面筋含量、沉降值、吸水率、稳定时间和评价值等加工品质最好,世玛处理则使营养品质和加工品质最差,巨星和骠马处理影响相对较小.籽粒灌浆期间,2,4-D丁酯处理使旗叶SOD、CAT和POD活性一直较低,尤其是籽粒灌浆末期活性最低;其它除草剂使旗叶SOD、CAT和POD活性在不同灌浆时期存在差异:灌浆前中期,骠马处理使3种保护酶活性最高;灌浆后期,世玛处理使旗叶中保护酶活性下降缓慢,且活性最高.籽粒灌浆期前期,4种除草剂对旗叶中MDA含量的影响是:世玛＞骠马＞CK＞巨星＞2,4-D丁酯,灌浆中后期,2,4-D丁酯和巨星处理使MDA含量快速提高,世玛和骠马处理使MDA含量升高相对较慢,到灌浆末期,2,4-D丁酯使MDA含量最高,世玛处理最低.图5表2参22     

单甲脒农药对大豆—土壤系统的生态影响

研究了单甲脒农药（DMAH）对大豆－土壤系统的生态影响．结果表明：除CK外，5个设置浓度［（DMAH）／mL·L－1］0．25、0．5、2．5、5.0、25均对大豆虫害有不同的防治效果．其中＞2．5时可防治大豆多种虫害；大豆对DMAH稀释液的pH值反应敏感，高浓度处理的叶片因酸度大而出现药害；推荐浓度［（DMAH）＝0．25mL·L－1］，对植株的生长和生理功能有促进作用．可使总生物量及产量分别增加20％左右，且籽粒中农药无残留，土壤农药残留量也小；当处理pH值＜5时会对叶片有伤害．生理功能被抑制，总生物量及产量都不如CK；DMAH在植物器官及土壤都有不同程度的残留量．其中叶残留量大于籽粒及土壤．可以认为，低浓度DMAH处理不会对植物－土壤系统造成污染．     

坡地赤红壤物理退化及其机理研究──Ⅲ.土壤物理退化机理分析

主要通过相关统计和综合分析，探讨坡地赤红壤物理退化的内部和外部环境的影响因素．指出养分贫瘠化，尤其是贫有机质化是坡地赤红壤物理性状退化的主要内部原因，植被破坏则是坡地赤红壤物理性状退化的外部因素、而人类活动的影响对坡地赤红壤的物理退化有重要作用。     

烟草病程相关蛋白PR-1a的三维模型和荧光光谱

利用同源模建和分子动力学模拟方法搭建了烟草病程相关蛋白PR-1a的三维结构，在此基础上预测出PR-1a具有2个可能的活性位点，进一步分析PR-1家族特异保守序列，结果显示位点1的可能性更大．利用蛋白质内源荧光为探针，对分离的重组表达PR-1a蛋白进行了热稳定性研究．低于60℃处理，PR-1a蛋白内源荧光只略微降低；70℃处理30min引起PR-1a蛋白内源荧光明显降低，结果显示，PR-1a中色氨酸残基主要处于蛋白质分子内部，这与三维结构模型预测结果相符．图5参15     

玉米铝（Al）胁迫研究初报

通过试验和分析，研究Ａｌ胁迫下的玉米生物性状和主要生理特性，明确活性铝浓度与玉米根系特征及地上部农艺性状之间存在极显著或显著的反比相关；活性铝的存在，降低玉米茎叶Ｎ、Ｐ、Ｋ等养分含量，提高叶片脯氨酸累积量；脯氨酸含量可作为玉米耐Ａｌ性的生理指标．     

玉米自交系吸收利用磷素的差异及其相关性

大田选取11份玉米自交系，在两个供磷水平下研究了玉米自交系籽粒产量基因型差异及吸收效率、利用效率与磷效率的相关关系。试验结果表明：在磷胁迫的条件下，不同玉米自交系不仅产量存在较大的差异，而且对磷的响应度也不相同，产量最高的基因型中宗2号为最低的忻9005的5．15倍，将这些品种在二磷水平下以产量进行磷效率双向划分可以分为4种类型：双高效型(太411、KH12、58、中宗2号)；高磷高效型(187)；低磷高效型(冀257)；双低效型(478、冀35、XL12、忻9005、H21)，成熟期吸收、利用效率与磷效率的关系表明，在同一供磷条件下，11份自交系吸收、利用效率均有显著的差异，在两个供磷水平下，吸收效率与磷效率存在显著的正相关关系，而利用效率仅在高磷条件下与磷效率存在正相关性，表明在低磷水平下，成熟期磷效率主要由吸收效率决定，在高磷水平下，磷效率是吸收效率和利用效率共同作用的结果。图2表1参7。     

模拟控制性分根交替滴灌对玉米的节水效应

以盆栽玉米为试材，模拟田间控制性分根交替滴灌(Controlled Root-divided alternative Drip Irrigation，简称CRDADI)供水方式对夏玉米净光合速率、气孔导度、蒸腾速率、水分利用效率及其根冠比的影响。结果表明，控制1／2根区交替滴灌(ADL)比常规滴灌(CK)节水25％而生物量仅下降9％，水分利用效率和根冠比均明显增加，气孔导度和蒸腾速率下降明显而净光合速率变化很小，蒸腾效率明显提高；控制：1／2根区固定滴灌(FDI2)水分利用效率虽然是CK的1．2倍，但生物量仅为CK的60．1％，ADI1的66．0％，严重影响了玉米的正常生长；控制1／2根区交替滴灌(ADI)比控制1／2根区固定滴灌(FDI)的根冠比、根干质量和根条数增加且根系分布均匀，地上部分生物量增加。表明控制性分根交替滴灌(ADI)能在不牺牲作物光合产物积累的前提下提高玉米的水分利用效率。     

兔子宫内膜蛋白等电聚焦电泳柱状胶与板状胶电泳效果的比较

哺乳动物早期胚胎发育过程中，胚泡附植的成功与否对早期胚胎的发育十分重要．为了有效地弄清胚泡附植的分子机制，本研究从分析蛋白质的一种生化技术-等电聚焦电泳着手，利用兔子宫内膜蛋白作为实验材料，探讨了柱状胶与板状胶等电聚焦电泳分离蛋白质的电泳效果．研究结果表明：在相同情况下，柱状胶与板状胶的蛋白质分布有一些差别，pH梯度分布也不一致；板状胶比柱状胶pH值分布宽、蛋白质谱带多、分辨率高；板状胶酸性端只有1—2cm没有蛋白带、蛋白带分布比较均匀且压得比较紧．这说明在用子宫内膜作为实验材料进行电泳时用板状胶进行电泳的结果较好．     

成熟小麦种子中残留的α-淀粉酶对小麦馒头品质的影响

α-淀粉酶通过降解淀粉产生发酵糖,并改变淀粉的物化特性,进而影响小麦制品的品质,其影响与α-淀粉酶来源、含量及小麦制品种类有关.成熟小麦籽粒中残留的α-淀粉酶活性存在极大差异,为了解迟熟α-淀粉酶对馒头品质的影响,以重组自交系群体中α-淀粉酶活性极端的小麦品系为材料,比较高低酶活材料制作的馒头品质之间的差异;并依据小麦材料α-淀粉酶活性的分布范围,设定不同的外源α-淀粉酶浓度,研究外源α-淀粉酶对小麦馒头质构、感官品质及微观结构的影响.结果显示,过高的内源α-淀粉酶含量(降落值小于300 s)会导致馒头的高径比及质构参数下降,这种变化趋势与添加过多外源α-淀粉酶的效果类似;α-淀粉酶含量过高,造成淀粉糊化过度,产气过多,馒头内部结构被破坏,持气能力降低,馒头塌陷;降落值不低于300 s的材料制作的馒头品质较好.本研究表明成熟种子中残留的α-淀粉酶对馒头品质有显著影响,优质馒头品种选育时应关注小麦α-淀粉酶活性的差异.(图4表11参35)     

Assessment of deposition of MEMC (seed dressing fungicide) in exposed rice grain through study of seedling growth parameters

Rice seed grains exposed to 240 ppm of seed dressing fungicide, MEMC showed increase in deposition of mercury with increase in period of observation (0h to 48h) in 765+/-5 mg of intact endosperm. The gradual increase in mercury deposition in intact endosperm caused simultaneous decrease in mercury content of the seed coat. Exposure periods of 5 to 20 min with 240 ppm of MEMC showed 5.5 to 8.72 microg of mercury deposition in 765+/-5 mg of intact endosperm. Increase in period of exposure (3 to 20 min) to 240 ppm of MEMC and also increase in chronic treatment to lower concentrations (1.5 ppm to 24 ppm) to seed grains have shown similar results in seedling growth parameters. Lower period of exposure or exposure to lower concentrations, both showed a significant inhibition of root growth, however the shoot growth showed stimulation. But higher exposure period or exposure to higher concentrations brought inhibition of both root and shoot growth. The exposure period showing 50% of root growth inhibition of 72h old seedling was calculated to be 10 min So also the chronic treatment showing the 50% of root growth inhibition was calculated to be 9 ppm. Ten min exposure of rice grain to 240 ppm of MEMC showed deposition of 7.11 microg of mercury in 765+/-5 mg of intact endosperm at 48h of observation (optimal phase of germinating process). Regression analysis indicated that by the time of 72h the intact endosperm and developing seedling might have acquired with a minimum amount of 10.23 microg of mercury from the seed coat. Finally it can be said that 10.23 microg of MEMC might be bringing 50% root growth inhibition in 72h old seedlings and 16.71 microg of mercury causing 50% inhibition of both root and shoot growth of 120h old seedlings.     

糯小麦回交改良群体中Wx基因的遗传和品质效应

在基因型鉴定的基础上,利用糯小麦杂交后代BC5F2代回交改良群体研究了各基因缺失对降低直链淀粉含量的效果和各基因合成直链淀粉的能力,以及直链淀粉含量与农艺性状、品质性状、淀粉糊化特性等的相关性。研究发现,在Wx基因的所有8种基因型之间,直链淀粉含量差异显著;研究单缺失基因型发现,对直链淀粉含量减少效应最大的是Wx-B1b,减少效应最小的是Wx-A1b,而Wx-B1b和Wx-D1b没有显著差异;研究双缺失基因型发现,Wx基因合成直链淀粉的能力以Wx-B1a最高,Wx-A1a最低,而Wx-B1a和Wx-D1a差异很小.直链淀粉含量与株高、穗长、小穗数、穗粒数、千粒重等农艺性状相关不显著,表明淀粉品质育种可以与高产育种实现有机结合.直链淀粉含量与SDS-沉降值呈显著负相关(r=-0.726),说明直链淀粉含量降低在一定程度上有利于提高小麦营养与加工品质.全糯类型的淀粉糊化特性与其他类型显著不同,具有最高的峰值粘度和稀懈值,最低的低谷粘度、最终粘度、反弹值、峰值时间、糊化温度、起始糊化温度,表明糯小麦淀粉在食品和工业上具有特殊用途;稀懈值与直链淀粉含量呈极显著负相关(r=-0.969),其它粘度参数与直链淀粉含量呈显著正相关(最终粘度r=0.797,低谷粘度r=0.910、反弹值r=0.954、峰值时间r=0.970、糊化温度r=0.962、起始糊化温度r=0.932).表5参37     

Performance study on portable water filters

This study explored the effectiveness of five portable water filters for improving certain physical, chemical and biological parameters related to drinking water quality. The parameters investigated included: turbidity, total suspended solids, true and apparent colour, conductivity, pH, alkalinity, hardness, and heterotrophic plate count. In general, ceramic medium water filters improved water quality the greatest and with the incorporation of activated carbon a further reduction in colour and dissolved solids was possible.     

A study on the landfill leachate and its impact on the groundwater quality of the greater area

Characterisation of the leachate originating from the Ano Liosia landfill (situated in Attica region, Greece) as well as assessment on the quality of the local aquifer were carried out. The experimental results showed that most of the parameters examined in the leachate samples such as colour, conductivity, TS, COD, NH₃–N, PO₄–P, SO₄ ^2–, Cl^–, K⁺, Fe and Pb were found in high levels. The organic load was quite high since the COD concentrations were in the range of 3250–6125mgL^–1. In addition, the low BOD/COD ratio (0.096–0.195), confirmed that the majority of this organic matter is not easily biodegradable. The groundwater near the landfill site was characterised as not potable and not suitable for irrigation water, since most of the physical and chemical parameters examined – such as colour, conductivity, DS, hardness, Cl^–, NH₃–N, COD, K⁺, Na⁺, Ca²⁺, Fe, Ni and Pb exceeded the permissible limits given by EE, EPA and the Greek Ministry of Agriculture. Furthermore, this study presents the application of the hydrologic evaluation of landfill performance (HELP) model for the determination of the yearly leakage from the base of the landfill after the final capping.     

钼和硼污染对大豆品质的影响

以3个大豆(Glycine max)品种(浙春3号、浙春2号和3811)为材料，设置了4个钼、硼处理(适量钼和硼、高钼、高硼及高钼高硼同施)，研究了钼污染和硼污染对大豆品质的影响．结果表明：高钼或高硼促使大豆种子蛋白质、维生素C、氮、磷、钾的含量显著减少，氨基酸的总量和必需氨基酸的总量大大降低，氨基酸各组分(除脯氨酸外)的含量都明显下降，脂肪的组分也发生变化，对种子中钙镁含量的影响不大，且高硼对大豆品质的毒害作用明显大于高钼．在过量条件下，钼和硼在大豆体内呈现相互抑制作用．3个大豆品种的品质问存在一定的基因型差异，3个品种对高钼和高硼的反应也存在差异．图2表3参18     

Chemometrical analysis and quality control of pot water and its sources from Athens,Greece

The present study describes a chemometrical interpretation of a large data set from pot water quality control results. Sixteen chemical and physicochemical parameters constantly checked throughout the year were involved in the classification procedure. The data originate from seventeen sampling stations (pot water sources and pot water purification stations) and were collected in the period January ‐December 1993. Mean values for two months periods were introduced to the chemometrical procedure, so finally a data set 101x16 was formed. Additionally, quality control requirements of the European Union for pot water were added to the set to form an information input matrix of 103x16 elements. Hierarchical and non‐hierarchical clustering procedures were applied in order to reveal the internal structure of the data set. Some interesting conclusions like special water quality of lake Mornos, possibility of quality monitoring with lesser number of components etc., concerning the quality and stability of the pot water sources and quality characteristics of the samples are made.     

镉对桑蚕生长发育和蚕茧质量影响的研究

研究了土壤镉对桑叶含镉量［w（Cd）］、含水量［w（H2O）］的影响以及镉对蚕生长发育和蚕茧质量的影响结果表明：（1）桑叶w（Cd）与土壤w（Cd）呈极显著正相关（2）土壤w（Cd）＞22．3×10-6,则桑叶w（H20）＜75％，叶质开始变粗硬,（3）用w（Cd）＜3．66×10-6的添加Cd桑叶养蚕时，蚕能正常生长发育，蚕茧质量不受影响（4）当镉由土壤进入桑叶，用w（Cd）＜0．49×10-6的桑叶养蚕时，蚕的生长发育和蚕茧质量不受明显影响（5）当桑叶w（Cd）超过上述数值后，蚕的生长发育受阻，蚕茧质量明显下降。     

管网生物膜菌株胞外聚合物的提取方法比较

以饮用水管网生物膜样品中一株强成膜能力的菌株Pleomorphomonas oryzae作为研究对象,考察了8种方法(高速离心法、超声法、加热法、EDTA法、H2SO4法、NaOH法、SDS法、甲醛法)对菌株胞外聚合物(EPS)的提取效果,并结合三维荧光光谱(EEM)和傅立叶红外光谱(FTIR)对提取的EPS进行成分分析.结果表明,EDTA法和H2SO4法既能提高EPS的提取效率,提取量分别为64.77 mg.g-1SS和74.43 mg.g-1SS,是离心方法提取量的1.62倍和1.86倍,又不会在提取过程中对菌株细胞造成破坏,是较为理想的EPS提取方法.EEM分析进一步证实,NaOH法对菌株细胞破坏严重,造成EPS成分变化较大.FTIR分析则说明,化学提取方法相较于物理提取方法会引入杂质对组分测定造成干扰.     

Evolutionary relationships among deep-sea mytilids (Bivalvia: Mytilidae) from hydrothermal vents and cold-water methane/sulfide seeps

A protein electrophoretic survey of mytilids inhabiting deep-sea hydrothermal vents and cold-water methane/sulfide seeps revealed electromorph patterns diagnostic of 10 distinct species. From hydrothermal vents located at sites on the Galápagos Rift, the Mid-Atlantic Ridge, and the Mariana Back Arc Basin, we detected four species of mytilids. Six additional species were detected from three cold-water seep sides in the Gulf of Mexico. The patchy distribution and temporal stability of seeps may provide a greater opportunity for mytilid diversification and persistence than vent sites Nei's genetic distances (D) between species were relatively large (range: 0.528 to ) both within and among habitat types. This pronounced degree of genetic differentiation suggests a relatively ancient common ancestor for the group. Phylogenetic trees were generated using distance Wagner and parsimony analyses of allozyme and morphological characters. The tree topologies obtained from both methods support: (1) the hypothesis that a seep ancestor gave rise to the deep-sea hydrothermal vent mytilids, (2) a historical progression from shallow-water to deep-water habitats, and (3) a co-evolutionary progression from external to internal localization of bacterial symbionts. Whether the seep mytilid taxa constitute paraphyletic or polyphyletic groups remains unresolved. Our phylogenetic hypotheses also provide a benchmark for the phylogeny of mytilid bacterial symbionts.