去除基部果枝对早衰棉花棉铃对位叶SPAD值 及纤维素合成的影响

以荃银2号和冀杂999为试验材料,通过在花铃初期去除基部2个果枝,研究去除基部果枝对早衰棉花棉铃对位叶SPAD值和棉纤维合成相关物质含量变化的影响。结果表明,去除基部果枝后的处理组,其SPAD值较对照组高;同时,去除基部果枝对棉纤维中蔗糖的转化率也有影响,主要表现为棉纤维中蔗糖转化率处理组高于对照组,且伏桃蔗糖转化率高于秋桃蔗糖转化率;随着铃龄的增加,去除基部果枝后的棉纤维中纤维素含量高于对照组纤维素含量。去除基部果枝可以延长棉铃对位叶的功能期,提高棉纤维中蔗糖转化率,有利于棉纤维素的生物合成。     

微藻污水处理与生物质能耦合技术综述

指出了微藻具有生产周期短、生物质营养丰富、吸收水中的氮、磷和大气中的二氧化碳等优点,是污水处理与生物质能耦合技术的不二选择。介绍了微藻在污水处理中的工作机理和微藻作为生物质能原料的原理和主要工艺过程,分析了微藻在污水处理和生物质能耦合上的可能性和存在的问题,对微藻污水处理与生物质能技术进行了综述。     

Accumulation of nitrous oxide and depletion of oxygen in seasonally frozen soils in northern Japan - Snow cover manipulation experiments

It has been suggested that soil-thawing and snow-melting are critical triggers for vigorous emissions of nitrous oxide (N₂O) from soils in cold regions. However, because soil freezing is affected by air temperature and snow cover, accurate predictions that estimate subsequent emissions of this important greenhouse gas are difficult to make. In this study, we measured in situ soil gas N₂O and oxygen (O₂) concentrations at two experimental sites in northern Japan over the period of a year, from November 2008 to October 2009, to clarify the factors stimulating N₂O production in soil at low temperatures. The sites were N-fertilized bare arable lands with different soil frost depths and snowmelt rates, according to the snow cover management imposed. Winter-to-spring net N₂O fluxes, ranging from −0.10 to 1.95 kg N₂O-N ha⁻¹, were positively correlated with the annual maximum soil frost depth (ranging from 0.03 to 0.41 m; r = 0.951***). In the plots with deeper maximum soil frost, winter-to-spring N₂O fluxes represented 58% to 85% of the annual values. Soil N₂O production was stimulated when the soil frost depth was greater than 0.15 m or the daily mean soil temperature at 0.05-m depth was below −2.0 °C. In the soil with the greatest frost depth, soil gas N₂O concentrations at the depth of 0.10 m peaked at 46 ppm when soil gas O₂ concentrations fell down to 0.12 m³ m⁻³ under soil temperature below 0.0 °C. Snowmelt acceleration had no stimulating effect on N₂O production in the soil during the winter-to-spring period.     

Pleuropneumonia in two horses caused by a tracheobronchial foreign body

Two horses suffering from a cough, purulent foul smelling nasal discharge, inappetence and intermittent fever were hospitalised at the Equine Clinic in Brno from 2008–2010. A diagnosis was made on the basis of endoscopic examination which revealed a foreign body (thorny branchlet) in the right caudal lobe bronchus in both horses. Pleuropneumonia developed as a complication in both horses. Following endoscopic extraction of the foreign bodies, both horses were treated using antibiotics and drainage of the pleural cavity. One of the patients recovered, the second was subjected to euthanasia at the request of the owner.     

Isolation of a citrus ethylene-responsive element binding factor gene and its expression in response to abiotic stress,girdling and shading

Information about citrus ethylene-responsive element binding factor (ERF) genes and their functions in fruit ripening or in stress tolerance is still scarce. In the present study, one of ERF genes, CitERF was isolated from fruit of Citrus unshiu with a maximal putative open reading frame encoding 207 amino acids. The deduced protein contains a region rich in acidic amino acids, an AP2/ERF domain and a KRRK nuclear localization signal. It belongs to group B of Class I in the ERF subfamily in which MdERF2 (Malus × domestica ethylene-response factor 2) and PsERF1b (Prunus salicina ethylene-response factor 1b) were involved in the progress of fruit ripening. CitERF mRNA level in fruit peel and pulp increased obviously along with fruit ripening. However, its expression could be reduced significantly by treatments of total shading and fruit-bear-shoot girdling plus defoliation during fruit ripening. As for the response to abiotic stresses, CitERF expression was found to be induced continuously during the treatment of 10% polyethylene glycol. On the other hand, it could be induced to high level at 1 h after the treatment of 4 °C or 250 mM NaCl and then declined continuously. Taken together, the results suggested that CitERF may play an important role in some biological processes during fruit ripening and in improving tolerance to drought, low temperature and salt stress.     

Relationships between strawberry fruit quality attributes and crop load

Crop load can influence fruit quality in several horticultural species. The aim of the present study was to determine the effect of different concentrations of calcium on crop quality traits in three short-day strawberry (Fragaria × ananassa Duch.) cultivars (‘Ventana’, ‘Camarosa’ and ‘Candonga’) and to assess the relationships between crop load and quality parameters. The studies were conducted using a hydroponic system in a greenhouse. Calcium was added as Ca(NO₃)₂ at 2 mM, 3 mM, 4 mM and 5 mM. A completely randomized block design (4 Ca concentrations × 3 cultivars) with three replicates was used. Each replicate consisted of 12 plants grown in polyethylene bags (100 cm × 18 cm × 3 cm) filled with coconut peat. Titratable acidity, total soluble solids and firmness were measured throughout the experimental period. Calcium application had no effect on fruit quality attributes but the genotype effect was clear. At the end of the experiment (28th May, 2008), titratable acidity was positively related to the fresh weight of above-ground biomass and number of leaves respectively in the ‘Ventana’ and ‘Camarosa’ cultivars. Higher values of total soluble solids were found at low crop load in ‘Ventana’ but in ‘Camarosa’ this relation was not found. In ‘Candonga’, higher total soluble solids were linked to crop load. In ‘Ventana’, titratable acidity significantly decreased as crop load increased, and in ‘Camarosa’ high values of titratable acidity were found at different values of crop load. ‘Ventana’ seemed to be more sensitive to the effects of crop load patterns. Genotype was an important factor in determining fruit quality parameters.     

八种室内观赏植物对甲醛的净化效果研究

选用8种常用室内观赏植物,将盆土与茎叶部分隔开,放入自行研制的甲醛熏气箱中,对植物进行熏气试验,测得熏气前后甲醛的变化量和植物叶面积,以单位叶面积甲醛减少量来比较8种植物吸收甲醛能力的大小。结果表明:甲醛质量浓度是国际标准10～15倍情况下,8种观赏植物均能吸收空气中的甲醛,但因种类不同吸收能力大小不一。吸收甲醛能力排序为:橡皮树>海芋>一叶兰>银皇后>马拉巴栗>散尾葵>红掌>孔雀竹芋。单位叶面积植物吸收甲醛量依次为:橡皮树>海芋>一叶兰>马拉巴栗>银皇后>散尾葵>红掌>孔雀竹芋。甲醛质量浓度是国际标准50～60倍情况下,8种观赏植物吸收甲醛能力排序为:一叶兰>银皇后>海芋>马拉巴栗>橡皮树>散尾葵>红掌>孔雀竹芋。单位叶面积植物吸收甲醛量依次为:一叶兰>马拉巴栗>海芋>橡皮树>银皇后>红掌>孔雀竹芋>散尾葵。根据单位叶面积吸收甲醛量的差异,将植物的吸收能力分为2类,吸收甲醛能力较强的植物有:一叶兰、马拉巴栗、海芋、橡皮树、银皇后(与空白组相比有显著性差异(P<0.05));较低的植物有:红掌、孔雀竹芋、散尾葵(与空白组相比无显著性差异)。     

基于遥感的山区土地覆盖分类研究 --以重庆市酉阳县为例

以酉阳县为例,利用TM卫星遥感影像及相关资料提取土地覆盖信息。针对山区地势起伏大、地形复杂,且常年多云雾、分类难度大的特点,着重加强对影像的地形校正、阴影去除、去云处理。以此来提高图像分类精度。研究结果表明,这种方法能有效的提取TM卫星遥感土地覆盖信息。     

全程自养脱氮体系中硝化菌株的筛选和鉴定

在建立全程自养脱氮反应器的基础上,以活性污泥为对照,分析了反应器内硝化菌和亚硝化菌的数量变化,并通过富集培养,从反应器中筛选、分离用于治理氮污染的硝化菌和亚硝化菌．研究结果表明,自养脱氮反应器内亚硝化菌数量显著增加,说明亚硝化菌积累是全程自养脱氮体系的一个显著特点．从反应器内富集到参与自养脱氮反应的细菌菌株,鉴定结果表明,参与亚硝化反应的菌株主要为铜绿假单胞菌（Pseudomonas aeruginosa）和食酸丛毛单胞菌（Comamonas acidovorans）;参与硝化反应的菌株主要为睾丸酮丛毛单胞菌（Comamonas testoseroni）,同时测定了铜绿假单胞菌（Pseudomonasaeruginosa）的亚硝化能力和睾丸酮丛毛单胞菌（Comamonas testoseroni）的硝化能力．     

氮、磷、钾肥配施对空心多茎株型短季棉产量的效应研究

采用三因子二次正交旋转组合设计,研究了N、P、K肥配施对空心多茎株型短季棉产量的效应。通过对试验结果进行单因子、二因子互作以及三因子综合效应分析,表明了三因子对产量的影响是K肥>N肥>P肥(影响比例是K肥∶N肥∶P肥=3.16∶2.37∶1),且K肥与N肥之间存在较明显的正互作效应,K肥和N肥应是生产中重点调控的因子;提出了以籽棉产量大于3750kg/hm2,施肥效益大于12000元/hm2为指标的高产高效施肥方案。