Does root-sourced ABA play a role for regulation of stomata under drought in quinoa (Chenopodium quinoa Willd.)

The Andean seed crop quinoa (Chenopodium quinoa Willd.) is traditionally grown under drought and other adverse conditions that constrain crop production in the Andes, and it is regarded as having considerable tolerance to soil drying. The objective of this research was to study how chemical and hydraulic signalling from the root system controlled gas exchange in a drying soil in quinoa. It was observed that during soil drying, relative g_s and photosynthesis A_max (drought stressed/fully watered plants) equalled 1, until the fraction of transpirable soil water (FTSW) decreased to 0.82 ± 0.152 and 0.33 ± 0.061, respectively, at bud formation, indicating that photosynthesis was maintained after stomata closure. The relationship between relative g_s and relative A_max at bud formation was represented by a logarithmic function (r² = 0.79), which resulted in a photosynthetic water use efficiency WUE_Amax_/gs$\text{WU}{\text{E}}_{A_{\text{max}}/g_{\text{s}}}$ of 1 when FTSW > 0.8, and increased by 50% with soil drying to FTSW 0.7–0.4. Mild soil drying slightly increased ABA in the xylem. It is concluded that during soil drying, quinoa plants have a sensitive stomatal closure, by which the plants are able to maintain leaf water potential (ψ_l) and A_max, resulting in an increase of WUE. Root originated ABA plays a role in stomata performance during soil drying. ABA regulation seems to be one of the mechanisms utilised by quinoa when facing drought inducing decrease of turgor of stomata guard cells.     

日光温室内光合有效辐射基本特征分析

基于日光温室内观测的辐射资料,对光合有效辐射特征及对作物的影响进行研究分析.结果表明:温室内日光合有效辐射累计值与日水面蒸发量呈较好的线性关系,相关系数为0.7974;日光温室内作物光合速率随光合有效辐射上升到一定程度后,将不随光合有效辐射的增加而增加;叶片细胞液质量分数与光合有效辐射日变化均呈单峰型曲线,叶片细胞液质量分数相对于光合有效辐射有明显的滞后现象;日光温室内冬、春季晴天及阴天的太阳总辐射Q和光合有效辐射(PAR)日变化均为单峰型曲线,晴天和阴天太阳总辐射和光合有效辐射日变化趋势一致,阴天比晴天小;2007年秋季和2008年春季日光温室内小型西瓜的光合有效辐射利用率分别为6.38%和6.31%,高于大田作物的光合有效辐射利用率值.     

长白山森林土壤有机碳库大小及周转研究

主要分析不同森林植被下有机碳的分解动态和土壤碳库各组分大小、周转时间。结果表明：土壤样品培养90天，CO2累计释放量表层大致为1723～5065mg／kg、下层大致为178～642mg／kg。分解速率总的趋势是前期快，后期慢，表层明显大于下层。大小顺序为：冷杉林〉针阔混交林和阔叶林〉针叶林。在不同植被下的表层和下层土壤中，活性碳占总有机碳的0．54％～1．67％，0．45％～5．48％．平均驻留时间为11～56天、60～88天；缓效性碳占总有机碳的23．0％～63．3％，33．2％～72．2％，平均驻留时间为4～70年、24～161年；惰效性碳占总有机碳的35．5％～75．5％．26．0％～65．%。表层土壤的总有机碳、活性碳、缓效性碳和惰效性碳含量都明显大于下层。凋落物的化学组成主要决定活性碳库、缓效性碳库含量，土壤的粘粒含量等性质主要决定惰效性碳库含量。     

农村电网中有源电力滤波器的研究

随着农村电网中电力电子装置的日益增多,农村电网中的谐波污染问题越来越严重.为此,简要分析了并联型有源电力滤波器的系统结构和工作原理;建立了采用DSP数字控制的适合于三相三线制的并联型有源电力滤波系统, 重点分析了该系统指令电流和PWM信号的产生、硬件结构与软件流程, 并通过实验验证了该系统可以有效地抑制农村电网谐波,改善农村电网电能质量.     

剩余污泥超声破解性能研究

采用超声波技术破解人工配水条件下培养的污泥，研究了超声破解含固率为0．5％与1％污泥的性能，并比较了超声破解2种含固率污泥的效果。结果表明，在一定声能密度下，SCOD增加值随时间延长线性增长。即在一定试验时间范围内，污泥破解反应相对于时间符合一级反应动力学规律。但是，在较高声能密度与较低污泥浓度下，SCOD增加值随时间延长不再呈线性增长趋势，而是随超声作用时间的延长，增长速度减缓。在相同比能耗下，破解含固率为1％污泥的SCOD增加值明显大于含固率为0．5％污泥值。若后续污泥处理工艺采用厌氧消化技术，则推荐破解含固率为1％的污泥。超声破解污泥后，污泥温度会升高，相同声能密度下，破解两种不同含固率污泥的温度升高值相近。     

城市污泥与稻草堆肥的腐熟度指标研究

采用翻堆方式将稻草与未消化城市污泥进行堆肥,测定常见几种化学和生物参数的变化,探讨其作为腐熟度指标的可行性。结果表明,(C/N)终点/(C/N)起始比值和铵态氮可作为堆肥腐熟度的指标,当(C/N)终点/(C/N)起始小于0.6和铵态氮浓度低于400mg·kg-1时,堆肥基本腐熟。水溶性有机碳与水溶性铵态氮之比值也可作为堆肥腐熟度的新的复合指标,当比值大于9时,堆肥基本腐熟。挥发性固体重、C/N、pH及NO3--N与堆肥原料有关,只可作为参考。     

污泥土地利用对环境的影响

污泥中含有丰富的有机质及氮、磷等养分，土地利用是污泥处理的重要途径之一。由于污泥的含水率很高，易腐烂发臭，且含有病原菌、重金属及毒性有机物等，在土地利用之前进行稳定化处理是必要的。在污泥的稳定化处理方法中以堆肥化处理较符合我国国情。污泥的土地利用对土壤物理、化学及生物学性质有明显的改良作用，可促进植物生长，提高产量及品质。同时，由于污泥中的重金属及丰富的氮素，使用不当，可导致重金属在土壤与植物中的积累，过量的硝态氮可能污染地表与地下水。     

Genetic immunization with the immunodominant antigen P48 of Mycoplasma agalactiae stimulates a mixed adaptive immune response in BALBc mice

A DNA vaccine against contagious agalactia was developed for the first time, encoding the P48 of Mycoplasma agalactiae. Specific immune responses elicited in BALB/c mice were evaluated. Both total IgG and IgG1 were detected in mice vaccinated with pVAX1/P48. Proliferation of mononuclear cells of the spleen, levels of gamma interferon, interleukin-12, and interleukin-2 mRNAs were enhanced in immunized animals. Results indicate that pVAX1/P48 vaccination induced both T_h1 and T_h2 immune responses. Nucleic acid immunization could be a new strategy against M. agalactiae infections and may be potentially used to develop vaccines for other Mycoplasma diseases.     

植被光合有效辐射吸收分量及最大光能利用率算法的改进

植被冠层对入射光有效辐射的吸收系数 (FPAR) 和最大光能利用率是NPP模拟的重要参数。利用光量子仪实测了典型草原植被类型关键生育期光合有效辐射值,根据NDVI与FPAR之间的良好相关性,建立了2个FAPR估算模型。结果表明,实测的FPAR值与模型估算的FPAR之间的相关性均达到极显著水平,2个模型的估测值之间没有显著性差异。因此,本研究中采取求均值后计算了我国草原的FPAR,并与NASA-FPAR产品进行了嵌套和互补,形成全国完整的草原FPAR空间分布图。同时,基于归一化植被指数和叶面积指数,以中国草原18大类分类结果为基础单元,对中国草原18大类的最大光能利用率进行调整,调整后的最大光能利用率输入NPP模型后,改善了NPP估算精度,在大类尺度上,总体预测精度为85.71%。     

Functional Analysis of ABC Transporter Genes From Botrytis cinerea Identifies BcatrB as a Transporter of Eugenol

The role of multiple ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporter genes from the plant pathogenic fungus Botrytis cinerea in protection against natural fungitoxic compounds was studied by expression analysis and phenotyping of gene-replacement mutants. The expression of 11 ABC (BcatrA–BcatrK) and three MFS genes (Bcmfs1, Bcmfs2 and Bcmfs4) was studied. All genes showed a low basal level of expression, but were differentially induced by treatment with cycloheximide and the plant defence compounds camptothecin, eugenol, psoralen, resveratrol and rishitin. The latter compounds induced expression of BcatrB at a high level. Eugenol was more toxic to BcatrB gene-replacement mutants than to the control isolates. Eugenol also caused an instantaneous increase in mycelial accumulation of the fungicide fludioxonil, a known substrate of BcatrB. However, there was no difference in virulence between the wild-type and BcatrB gene-replacement mutants on Ocimum basilicum, a plant known to contain eugenol. The results indicate that BcatrB is a transporter of lipophilic compounds, such as eugenol, but its role in virulence remains uncertain.