能源甘蔗不同叶位叶片形态、光合气体交换及其与产量关系

利用CI-203叶面积分析仪和CI-301CO2气体分析仪分析4个能源甘蔗品种分蘖期和伸长初期不同叶位层叶片的形态特征和光合气体交换特征参数.结果表明,不同基因型不同叶位层间叶片形态、光合气体交换特征参数存在显著差异.分蘖期和伸长初期蔗叶的叶长、叶宽、叶面积、长宽比等叶片形态参数和净光合速率、蒸腾速率、气孔导度和水分利用率等光合气体交换特征参数均表现为随着叶位的下降,自上而下逐渐变小.逐步回归分析结果表明,分蘖期第3叶的叶宽和水分利用率及第5叶的叶宽对产量形成影响较大;而伸长初期第1叶和第3叶的叶面积对产量形成影响较大.图8表4参15     

珠江三角洲稻田土壤砷及其向水稻籽粒迁移特征

采集珠江三角洲区域水稻(Oryze sativa L.)植株的根系、秸秆、稻谷和对应的耕层土壤(0～15锄)样品,分析土壤和水稻植株中砷含量,初步研究土壤砷与土壤基本理化性质的关系及砷在土壤-水稻系统中的迁移规律.结果表明,土壤砷含量在1.83～18.14 mg·kg~(-1)之间,土壤砷与土壤有机质、砂粒含量呈显著负相关,与土壤粉粒含量呈显著正相关.糙米中的砷含量在0.21～0.43mg·kg~(-1)之间,均未超过国家食品卫生标准(0.7mg·kg~(-1)),砷在水稻植株中的分布规律为根>秸秆>颖壳>糙米.糙米砷含量与秸秆砷含量呈极显著正相关,与秸秆中P/As、Si/As摩尔比呈极显著负相关,因此,降低秸秆中As的积累、增加秸秆中P、Si的积累可降低水稻籽粒中的砷含量.     

L-山梨糖还原酶基因在大肠杆菌中的表达及融合蛋白的酶学特性

为获得L 山梨糖还原酶 (SR)整个操纵子序列 ,以 pGEM 3zf( )作为载体构建了Gluconobactersp .S6基因文库 .结合转化子在以L 山梨糖为唯一碳源培养基上的生长情况 ,利用PCR技术筛选到一个含L 山梨糖还原酶基因的阳性克隆pGEM 3zf( ) sr3/E .coli,酶切鉴定插入片断长度约 5 .0kb左右 .以 pGEM 3zf( ) sr3/E .coli质粒DNA为模板 ,扩增SR结构基因 .PCR产物经测序验证为SR基因序列后 ,与表达载体Pet32a( )相连 ,转化宿主大肠杆菌AD4 94 (DE3)对SR基因进行表达 ,并利用重金属离子亲和层析技术对SR融合蛋白进行了纯化 ,对其酶学特性进行了研究 .结果表明 :还原型辅酶II(NADPH)是SR酶蛋白的最适电子供体 ;SR酶蛋白的最适反应pH为 7.0 ,pH为6 .5时保持稳定 ,酶活力较高 ;最适反应温度是 5 0℃ ,30℃时热稳定性较好 .SDS PAGE电泳分析 ,SR融合蛋白的Mr 在6 5× 10 3 左右 ,由此推测出天然SR的Mr 在 5 3× 10 3 左右 ,与SR基因序列推测出的分子量大小一致 .图 13表 2参 6     

中药青蒿鲨烯合酶的大肠杆菌表达、纯化与功能鉴定

利用PCR方法,将经RACE方法克隆到的中药青蒿鲨烯合酶cDNA(AF302464)开放阅读框的3′末端截短99bp,插入到原核表达载体pET30a( )的NcoⅠ和BamHⅠ酶切位点之间,构建N端和C端均携带有HIS6表达标签的鲨烯合酶重组表达载体pETSSA.将pETSSA转入大肠杆菌BL21(DE3),0.5mmol/LIPTG(isopropyl-beta-D-thiogalactoside)28℃诱导重组鲨烯合酶的表达.表达产物经镍琼脂糖柱纯化.纯化蛋白加入酶促反应体系(含FPP和NADPH),GC-MS分析酶促反应体系的正己烷萃取物,结果显示重组鲨烯合酶可以催化FPP向鲨烯的转化.青蒿鲨烯合酶的功能鉴定为进一步利用反义或RNAi技术限制甾类生物合成,从而提高青蒿中的青蒿素含量提供了基础.图5参15     

水稻磷效率差异的生理生化特性

以磷效率差异显著的IR71379—2B—10—2—3-1(磷低效型)、IR7133l-2B-2-1(中间型)及IR74(磷高效型)3个品种为供试材料，采用水培法研究了它们对磷的吸收效率、运输效率及植株体内磷的利用效率，进而研究了其对低磷胁迫的根系形态学和生理生化机制的适应性反应．结果表明：水稻磷效率的高低是由基因型对磷的吸收效率，运输效率及利用效率综合作用的结果．磷高效基因型IR74和磷效率表现为中间型的IR71331-2B-2-1具有高的磷吸收效率．旺盛的根系生长，高的根系活力，Km、Cmin小，Imax大及相对酸性磷酸酯酶(APase)活性高等是水稻对磷高效吸收的特征．但品种不同特征也有别，本试验中的IR74对磷高的吸收效率主要是由于根系生长旺盛，根系吸收面积大所致，而IR71331-2B-2-1高的磷吸收效率则主要缘于根系活力强，Imax大．低磷胁迫下，叶片中核糖核酸酶的活性也大大升高，约是对照的10～15倍，但品种间无显著差异．图2表6参21     

长穗颈(eui)水稻上部节间伸长与植物激素的关系

选取含有诱变的长穗颈基因eui1、eui2和野生型基因Eui的水稻(OryzasativaL.)协青早保持系3个等基因系,通过供试植株在不同生育期的GA1和ABA含量测定及喷施GA合成抑制剂,并辅之器官删除试验等方法,探索长穗颈水稻上部节间伸长的生理机制.结果表明,在抽穗期,含eui1的协青早保持系XeB1幼穗和剑叶里的GA1含量显著增加,分别约为对照协青早B的16倍和3.4倍,其GA1/ABA比值也明显增加;含eui2的XeB2幼穗和剑叶里的GA1含量显著提高,但仅在剑叶里GA1/ABA比值明显增加,其幼穗内的GA1水平显著低于XeB1.GA合成抑制剂S3307处理使XeB1和XeB2的株高生长均受到严重抑制.删除幼穗使XeB1最上节间伸长的受抑程度远大于XeB2和XB.由此推测,在抽穗期,eui1能使水稻自身产生GA1,高含量的GA1诱导了长穗颈水稻最上节间的剧烈伸长;在促进最上节间的伸长方面eui1强于eui2.图5表1参12     

The prevalence of heavy metals in Cladophora glomerata L. from Farahabad Region of Caspian Sea – Iran

The presence of toxic heavy metals in the environment is considered as a risk factor for adverse human and environmental health effects. Farahabad Region is a tourist center in the southern coast of Caspian Sea in Mazandaran Province of Iran. Environmental monitoring of this site is important for public health for individuals visiting and residing in this region. Although numerous biomonitoring data are available globally, very few if any apparent investigations have been conducted in this region. In this study, concentration of three heavy metals chromium (Cr), lead (Pb), and cadmium (Cd) was determined for one year in Cladophora glomerata, the predominant macroalga species present in this region. Detection of heavy metals was performed with atomic absorption spectrophotometer using standard methods. Results showed that the range of Cr metal in various algal samples was 29–55 ppm/g dry weight. The levels of Pb in algal samples (Cladophora) ranged from 2 to 8 ppm/g dry weight. The Cd concentrations in C. glomerata biomass ranged from 1.5 to 8.2 ppm/g dry biomass. In view of potential threats of such high metal concentrations in coastal waters and in algal tissues, it is necessary to adopt conservation measures to ensure public health safety.     

孔雀草对镉胁迫的响应及其积累与分布特征

采用营养液培养法研究了不同浓度的Cd(0、0.01、0.05、0.1、0.2、0.3、0.4 mmol·L-1)对孔雀草叶片光合色素和丙二醛含量以及Cd积累量、亚细胞与化学形态分布的影响.结果表明,随着营养液Cd浓度的增加,叶片光合色素含量呈先升后降趋势,丙二醛含量则呈线性递增趋势,高浓度Cd处理(≥0.1 mmol·L-1)对孔雀草产生了显著的胁迫响应.Cd主要贮存于可溶组分中,根系中占50.91%—66.40%,叶片中占39.09%—60.52%;其次为细胞壁,细胞器中的镉比例较低.随着Cd处理浓度的增加,Cd在根系细胞壁中的贮存比例呈增加趋势.液胞区隔化和细胞壁固持是孔雀草应对Cd胁迫的重要耐性机制.根系中的Cd主要以乙醇提取态存在,占27.62%—70.46%,叶片中Cd主要以去离子水提取态和氯化钠提取态存在,两者合计占58.91%—71.09%.叶片中活性态Cd含量显著低于根系,显著降低了地上部Cd的积累,也显著降低了Cd对地上部的胁迫作用.     

A role for selective contraception of individuals in conservation

Contraception has an established role in managing overabundant populations and preventing undesirable breeding in zoos. We propose that it can also be used strategically and selectively in conservation to increase the genetic and behavioral quality of the animals. In captive breeding programs, it is becoming increasingly important to maximize the retention of genetic diversity by managing the reproductive contribution of each individual and preventing genetically suboptimal breeding through the use of selective contraception. Reproductive suppression of selected individuals in conservation programs has further benefits of allowing animals to be housed as a group in extensive enclosures without interfering with breeding recommendations, which reduces adaptation to captivity and facilitates the expression of wild behaviors and social structures. Before selective contraception can be incorporated into a breeding program, the most suitable method of fertility control must be selected, and this can be influenced by factors such as species life history, age, ease of treatment, potential for reversibility, and desired management outcome for the individual or population. Contraception should then be implemented in the population following a step‐by‐step process. In this way, it can provide crucial, flexible control over breeding to promote the physical and genetic health and sustainability of a conservation dependent species held in captivity. For Tasmanian devils (Sarcophilus harrisii), black‐flanked rock wallabies (Petrogale lateralis), and burrowing bettongs (Bettongia lesueur), contraception can benefit their conservation by maximizing genetic diversity and behavioral integrity in the captive breeding program, or, in the case of the wallabies and bettongs, by reducing populations to a sustainable size when they become locally overabundant. In these examples, contraceptive duration relative to reproductive life, reversibility, and predictability of the contraceptive agent being used are important to ensure the potential for individuals to reproduce following cessation of contraception, as exemplified by the wallabies when their population crashed and needed females to resume breeding.     

铜、锌污染对水稻土中油菜（Brassica chinensis L.）生长的影响及累积效应研究

通过盆栽试验,系统研究了Cu、Zn重金属污染对油菜（Brassica chinensis L.）生长、SOD保护酶活性、脯氨酸、可溶性糖及Cu、Zn在油菜体内吸收富集的影响。结果表明：Cu、Zn污染对油菜生物量和生理生化指标（SOD保护酶活性、脯氨酸和可溶性糖）均有影响。随着Cu、Zn质量分数的升高,植株干物重和SOD保护酶活性表现为先增后降;当Cu质量分数达到1 000 mg？kg-1时,油菜干物重和SOD酶活性分别比对照下降36.79%、66.67%;当Zn质量分数达到3 000 mg？kg-1时,油菜干物重和SOD酶活性分别比对照下降55.21%、82.05%。Cu污染下,油菜叶片脯氨酸质量分数逐渐下降,总可溶性糖质量分数表现为先增后降;Zn污染下,脯氨酸和总可溶性糖质量分数均表现为先增后降。Cu、Zn污染使油菜幼苗叶片及根中的Cu、Zn质量分数明显增加,根部的积累尤其明显。当Cu处理为1 000 mg？kg-1时,油菜茎叶和根中质量分数分别为57.6、424.162 mg？kg-1;当Zn处理为1 000 mg？kg-1时,油菜茎叶和根中质量分数分别为240、608.54 mg？kg-1。与Zn相比,Cu主要积累在油菜的根部,向茎叶迁移累积的量很少,并且随着添加质量分数的增加,茎叶吸收Cu的量变化不大。总之,重金属Zn相对于Cu更容易积累于油菜的地上部分,从而更易进入食物链,它们在油菜体内富集都对其生理生化和营养产生了明显毒害作用。