复合生态系统工程中高效去除磷,氮植被植物的筛选研究

对８种漫灌和垄沟处理和利用单元的植被植物进行了去除污水中磷、氮效能的筛选研究,以皇草为植被的垄沟系统具有较高的净化效能,ＴＰ和ＴＮ的去除率分别为８３．２％和７６．３％;以水稻Ｉ（８８－１３２）和水稻Ⅱ为植被的漫灌系统对污水中的Ｎ有很高的去除利用效能,去除率分别为８４．７和８４．３％。质量平衡的研究结果表明,对于以水稻Ｉ和水稻Ⅱ为植被的漫灌系统以及皇草为植被的垄沟系统而言,植物的吸收作用最主要的是去     

水稻中受体激酶的系统树分析

植物受体激酶(RLKs)在植物细胞内的反应中发挥着重要作用.为了比较拟南芥(Arabidopsis thaliana L.)和水稻(Oryza sativa L.)中受体激酶的进化关系,作者通过对北京华大基因研究中心(BGI)的籼稻蛋白质数据库进行BLASTP搜索,找到267个受体激酶类似基因,根据它们的胞外结构域可以将这些基因分为不同的类型.与拟南芥中受体激酶的系统树比较分析表明,不同类型的受体激酶具有不同的序列保守性,说明在植物进化过程中,不同类型的受体激酶具有不同的进化关系.水稻受体激酶与拟南芥受体激酶BRI1的多序列匹配结果也表明二者可能具有不同的磷酸化位点.     

水稻受盐抑制基因OsZFP1的转基因分析

OsZFP1(水稻锌指蛋白1)基因编码的蛋白含有3个推测的Cys2/Cys2-型锌指结构域,它的表达受盐胁迫负调控.构建了以35S为启动子的OsZFP1基因的植物表达载体,并将其转入拟南芥(Arabidopsis thaliana L.)植物和水稻(Oryza sativa L.)愈伤组织中以过量表达OsZFP1基因.转基因的拟南芥植株和水稻愈伤组织对盐处理的敏感性都比野生型要高.这一结果表明OsZFP1基因可能编码一种负调控蛋白,它可能抑制某些盐诱导基因的表达.在ABA处理下,转基因拟南芥植株比野生型植株抽苔晚,说明OsZFP1基因的作用可能受ABA调节.     

水稻中受体激酶的系统树分析

植物受体激酶(RLKs)在植物细胞内的反应中发挥着重要作用。为了比较拟南芥(Arabidopsis thaliana L.)和水稻(Oryza sativa L.)中受体激酶的进化关系,作者通过对北京华大基因研究中心(BGI)的籼稻蛋白质数据库进行BLASTP搜索,找到267个受体激酶类似基因,根据它们的胞外结构域可以将这些基因分为不同的类型。与拟南芥中受体激酶的系统树比较分析表明,不同类型的受体激酶具有不同的序列保守性,说明在植物进化过程中,不同类型的受体激酶具有不同的进化关系。水稻受体激酶与拟南芥受体激酶BRI1的多序列匹配结果也表明二者可能具有不同的磷酸化位点。     

不同胁迫预处理提高水稻幼苗抗寒性期间膜保护系统的变化比较

通过比较盐、冷和热激三种不同胁迫预处理提高水稻(Oryza sativa L.)抗寒性过程中膜保护系统的变化,探讨植物交叉适应机理。结果表明,水稻幼苗经不同胁迫预处理均可提高幼苗的抗寒性。与未预处理苗相比,不同胁迫(冷、热、盐)预处理之间在处理后、低温伤害后及恢复2d后的3个不同时期膜酶促和非酶促保护系统及同工酶酶谱变化各有异同,既有部分共性,也有其独特性。     

水稻U2snRNA基因的分离及结构分析

对水稻(Oryza sativa L.)基因文库中分离到的U2snRNA基因FDRGU2.3进行序列分析,其编码区与小麦(Triticum aestivum L、)、玉米(Zea mays L.)、豌豆(Pisum sativum L.)及拟南芥(Arabidopsis thaliana(L.)Heyhy.)等植物U2基因的同源性均大于80％,且5＇端70个碱基高度保守。在基因编码区上游-70及-30区分别包含有植物UsnRNA基因特有的上游顺序元件(USE)及类TATA元件。同其它植物一样,水稻U2.3snRNA的二级结构也有保守的4个茎环区。其中环Ⅱ的结构与单子叶植物中的小麦和玉米相同,但与双子叶植物的豌豆和拟南芥存在明显差异。环Ⅳ的结构在单子叶和双子叶植物中亦有不同的变化。这些差异可能意味着单子叶和双子叶植物的剪接机构有所区别。     

铁硫耦合影响甲基汞在土壤-水稻系统中迁移转化的研究进展

甲基汞(MeHg)具有较强的神经毒性,在稻谷中积累而产生的健康风险倍受关注。水稻(Oryza sativa L.)中甲基汞主要来源于稻田土壤,土壤中铁硫含量空间变异大,在水稻种植过程中因干湿交替作用以及根系泌氧作用而改变根际环境,使土壤甲基汞的含量及其迁移发生变化,从而影响其植物有效性。本综述系统总结了铁、硫及其相互作用对汞甲基化以及甲基汞在土壤-水稻系统中迁移转化的研究成果,并提出了甲基汞在土壤-水稻系统中迁移转化值得深入探究的相关问题,对进一步研究调控水稻中甲基汞含量以及其调控机制,降低健康风险具有重要意义。     

广东省湿地维管植物资源现状及保护利用

在对广东省湿地植被全面踏查的基础上,分析湿地植物资源现状并提出保护和利用对策。结果显示,广东省湿地维管植物共有96科240属352种,大部分为被子植物,其中含属数和种数较多的科有菊科、禾本科,含种数较多的属有莎草属Cyperus、蓼属Polygonum、母草属Lindernia、簕竹属Bambusa。出现频率较高的物种主要有喜旱莲子草Alternanthera philoxeroides(Mart.)Griseb.、凤眼蓝Eichhornia crassipes(Mart.)Solms、象草Pennisetum purpureum Schumach.、大薸Pistia stratiotes L.、铺地黍Panicum repens L.等。从生活型来看,多年生草本植物占总种数的71.59%,居主要优势;从生态类群来看,湿生植物占总种数的43.47%,居主要优势;从植物来源来看,本地物种占总种数的90.63%,居主要优势。入侵植物有41种,占总种数的11.66%。已开发利用的植物资源共204种,占总种数的57.63%。随着城市化进程的加快,开垦、采砂、排污等人为活动以及外来物种入侵使湿地环境遭到破坏,植物种类大大减少;用于园林绿化和净化污水的植物种类较少且多为外来种。建议合理开发湿地资源,加强外来物种的监控,多利用本地植物资源进行园林绿化和净化污水。     

小蓬草精油化感作用的生物测定

采用水蒸气蒸馏法从小蓬草[Conyza canadensis (L.)Cronq.]地上部分分离出精油,利用GC-MS技术对该精油的主要化学成分进行了鉴定,结果显示:精油提取率为0.07%;该精油主要含有2,3-二甲基-4(3H)-喹唑啉酮、α-佛手柑油烯、柠檬烯二醇、反式-β-金合欢烯和α-姜黄烯等成分,其中,2,3-二甲基-4(3H)-喹唑啉酮的相对含量最高,达到54.41%.以青菜(Brassica chinensis L.)、白菜[B. pekinensis (Lour.)Rupr.]、小麦(Triticum aestivum L.)和高粱[Sorghum bicolor (L.)Moench]为供试植物,采用培养皿法对不同质量浓度(0.75、1.5、3.0和6.0 g·L-1)小蓬草精油的化感效应进行了生物测定,结果显示:经不同质量浓度小蓬草精油处理后4种供试植物的种子最终发芽率和发芽指数以及幼苗的根长和株高等4个生物测定指标总体上均低于对照,且随精油质量浓度的提高不断降低,其中,0.75 g·L-1 精油处理组的4个生物测定指标均与对照无显著或极显著差异,而6.0 g·L-1精油处理组的4个指标与对照则有显著或极显著的差异.4种供试植物的4个生物测定指标的化感效应敏感指数几乎均为负值,且随精油质量浓度的提高敏感指数的绝对值逐渐增大,说明小蓬草精油对供试植物的化感作用为抑制作用,且抑制作用的强度与精油质量浓度有关.在4种供试植物中,小蓬草精油对青菜种子的最终发芽率的抑制作用最明显,其半抑制浓度(IC50)约为3.0 g·L-1;在4个生物测定指标中,种子最终发芽率以及幼苗根长对小蓬草精油的化感作用较敏感.研究结果表明,小蓬草精油具有一定的化感活性,可将其作为植物源除草剂原料进行开发利用.     

不同供氮水平的水稻叶尖的傅里叶转换红外光谱

四个氮素水平处理的盆栽水稻(Oryza sativa L.)的叶尖在不同生育期均表现出明显的傅里叶转换红外光谱差异.新定义的光谱指数((A3400-A1653)/(A3400+A1653),A为某频率处的吸收值)随着施氮水平的提高而降低.结果表明,傅里叶转换红外光谱可用于诊断植物的氮素状况.     

应用ACGM标记分析禾本科几个物种间的系统发生关系

为了验证水稻基因组数据的通用性,利用ACGM标记分析了禾本科几个不同种属植物的亲缘关系。选用10份材料,它们分别代表禾本科的5个属（Oryza,Zea, Setaria ,Triticum,和Phyllostachys）。根据遗传距离建立了一个聚类树。这5个属的亲缘关系可以简单地表示为：（（Oryza＋（Zea＋Setaria））＋Triticum）＋Phyllostachys。研究结果表明,水稻与玉米或水稻与粟之间的遗传距离比水稻和小麦或水稻与竹子之间的遗传距离近。     

Chemiluminescence during rice seed imbibition at different temperatures.

The chemiluminescence (CL) of rice (Oryza sativa L.) seeds at different temperatures and the CL spectra of rice seed, caryopses and seed coat were studied during early imbibition. Compared with the CL of barley (Hordeum vulgare L.) and soybean (Glycine max L. Merr.) seeds, the CL of rice seeds had a non-linear, logarithmic-like increase of intensity in the temperature range 30-50 degrees C. The Van't Hoff coefficient Q(10) = I(T+10)/I(T) was equal to 2. The emission spectrum of whole rice seed, rice and coat had a greater proportion of red light during early imbibition, which led to the conclusion that the CL of rice seed during early imbibition arises partially from enzyme-catalysed reactions.     

水稻品种化感潜力的双重评价与筛选

以初筛获得的7份水稻品种为材料,用特征次生物质标记法在HPLC上测定化感指数AI值并结合田间小区试验进行双重评价与筛选,得到3份既具高化感指数又具较高田间抗草活性的水稻化感品种(系),它们是:我国台湾品种I-Kung-Pao、Parahainakoru和大陆品种HB-1。它们对无芒稗根长抑制率分别达57%、64%、55%,均超过50%;其化感指数分别是0.61、0.56、0.59,均与美国化感潜力品种PI312777的化感指数0.59相近;结果表明,水稻品种I-Kung-Pao、Parahainakoru和HB-1是我国宝贵的化感品种资源。     

Integration of crop rotation and arbuscular mycorrhiza (AM) inoculum application for enhancing AM activity to improve phosphorus nutrition and yield of upland rice (Oryza sativa L.)

Upland rice (Oryza sativa L.) is a major crop of Eastern India grown during the wet season (June/July to September/October). Aerobic soils of the upland rice system, which are acidic and inherently phosphorus (P) limiting, support native arbuscular mycorrhizal (AM) activity. Attempts were made to improve P nutrition of upland rice by exploiting this natural situation through different crop rotations and application of AM fungal (AMF) inoculum. The effect of a 2-year crop rotation of maize (Zea mays L.) followed by horse gram (Dolichos biflorus L.) in the first year and upland rice in the second year on native AM activity was compared to three existing systems, with and without application of a soil–root-based inoculum. Integration of AM fungal inoculation with the maize–horse gram rotation had synergistic/additive effects in terms of AMF colonization (+22.7 to +42.7%), plant P acquisition (+11.2 to +23.7%), and grain yield of rice variety Vandana (+25.7 to +34.3%).     

Arsenic uptake and accumulation in rice (Oryza sativa L.) irrigated with contaminated water

Long-term use of arsenic contaminated groundwater to irrigate crops, especially paddy rice (Oryza sativaL.) has resulted in elevated soil arsenic levels in Bangladesh. There is, therefore, concern regarding accumulation of arsenic in rice grown on these soils. A greenhouse pot experiment was conducted to evaluate the impact of arsenic-contaminated irrigation water on the growth and uptake of arsenic into rice grain, husk, straw and root. There were altogether 10 treatments which were a combination of five arsenate irrigation water concentrations (0–8 mg As l^–1) and two soil phosphate amendments. Use of arsenate containing irrigation water reduced plant height, decreased rice yield and affected development of root growth. Arsenic concentrations in all plant parts increased with increasing arsenate concentration in irrigation water. However, arsenic concentration in rice grain did not exceed the maximum permissible limit of 1.0 mg As kg^–1. Arsenic accumulation in rice straw at very high levels indicates that feeding cattle with such contaminated straw could be a direct threat for their health and also, indirectly, to human health via presumably contaminated bovine meat and milk. Phosphate application neither showed any significant difference in plant growth and development, nor in As concentrations in plant parts.     

Estimating Carbon Capture Potential of Fallow Weeds in Rice Cropping Systems

Weeds occurred during the fallow season can well perform the function of carbon (C) capture due to receiving little human disturbance. This study aimed to evaluate the C capture potential of fallow weeds in rice (Oryza sativa L.) cropping systems. A six-region, two-year on-farm investigation and a three-year tillage experiment were conducted to estimate C capture in fallow weeds in rice cropping systems. The on-farm investigation showed that the average mean C capture by fallow weeds across six regions and two years reached 112 g m^–2. The tillage experiment indicated that no-tillage practices increased C capture by fallow weeds by 80% on average as compared with conventional tillage. The results of this study not only contribute to an understanding of C capture potential of fallow weeds in rice cropping systems, but also provide a reference for including fallow weeds in the estimation of vegetative C sink.     

水稻AtpH基因的表达受冷抑制

采用RT-PCR差异显示法,从水稻(Oryza sativa L.)幼苗克隆了1个受冷抑制表达的cDNA片段.该片段序列与水稻叶绿体基因组编码ATP合酶CF0Ⅲ亚基的atpH基因完全同源,且覆盖了atpH基因编码区.以Northern杂交分析了水稻幼苗在冷处理不同时间后的atpH基因转录水平,结果表明,atpH基因的转录受冷抑制,在冷处理第1天就明显下降,第2天以后完全受抑制.     

不同耐旱性水稻幼苗对氧化胁迫的反应

干旱条件下水稻(Oryza sativa L.)耐旱性较强的“湘中籼2号”比耐旱性较弱的“湘早釉12号”O_2~-的产生速率低。百草枯(0.01mmol/L)和H_2O_2(10mmol/L)处理促进干旱对水稻幼苗的伤害,但耐旱性较强的品种伤害较轻。单独用百草枯处理后,耐旱性较强的品种比耐旱性较弱的品种能更大幅度地提高超氧物歧化酶和过氧化物酶的活性;而H_2O_2处理后耐旱性较强的品种能提高过氧化氢酶活性。这些结果表明,耐旱性较强的水稻品种有较强的抗氧化胁迫能力。     

水稻AtpH基因的表达受冷抑制

采用RT-PCR差异显示法,从水稻（Oryza sativaL.)幼苗克隆了1个受冷抑制表达的cDNA片段。该片段序列与水稻叶绿体基因组编码ATP合酶CF0Ⅲ亚基的atpH基因完全同源,且覆盖了atpH基因编码区。以Northern 杂交分析了水稻幼苗在冷处理不同时间后的atpH基因转录水平,结果表明,atpH基因的转录受冷抑制,在冷处理第1天就明显下降,第2天以后完全受抑制。     

Characterization of photosynthesis, photoinhibition and the activities of C4 pathway enzymes in a superhigh-yield rice, Liangyoupeijiu

Characteristics of photosynthetic gas exchange, photoinhibition and C4 pathway enzyme activities in both flag leaves and lemma were compared between a superhigh-yield rice (Oryza sativa L.) hybrid, Liangyoupeijiu and a traditional rice hybrid, Shanyou63. Liangyoupeijiu had a similar light saturated assimilation rate (Asat) to Shanyou63, but a much higher apparent quantum yield (AQY), carboxylation efficiency (CE) and quantum yield of CO2 fixation (φCO2). Liangyoupeijiu also showed a higher resistance to photoinhibition and higher non-radiative energy dissipation associated with the xanthophyll cycle than Shanyou63 when subjected to strong light. In addition, Liangyoupeijiu had higher activities of the C4 pathway enzymes in both flag leaves and lemmas than Shanyou63. These results indicate that higher light and CO2 use efficiency, higher resistance to photoinhibition and C4 pathway in both flag leaf and lemma may contribute to the higher yield of the superhigh-yield rice hybrid, Liangyoupeijiu.