Development and validation of a range of endogenous controls to support the implementation of practical Taqman real-time PCR-based surveillance for fish diseases within aquaculture

The use of Taqman real-time PCR-based technology has recently become more frequent in the detection of pathogens in the aquaculture industry. This interest has necessitated the development of robust and reliable pathogen-detection assays. The development of a range of endogenous control assays to be run alongside these diagnostic assays works to further increase confidence in the latter. This study describes the design of a range of endogenous control assays based on the elongation factor 1-α (EF1-α) gene specific to a range of fish species including Atlantic salmon, Salmo salar; rainbow trout, Oncorhynchus mykiss; brown trout, Salmo trutta; cod, Gadus morhua; haddock, Melanogrammus aeglefinus; saithe, Pollachius virens; whiting, Merlangius merlangus; Norway pout, Trisopterus esmarkii; carp (family Cyprinidae), roach, Rutilus rutilus; European eel, Anguilla anguilla; and herring, Clupea harengus, as well as a number of fish cell lines. Evidence is provided of the validation of these assays for specific species, a range of tissue types and cell lines as well as an example of the potential uses of these assays.     

施肥模式对日光温室土壤铵态氮和硝态氮的影响

通过种植两茬油菜,设置7种施肥模式:有机肥施氮量600 kg/hm2;有机肥施氮量300 kg/hm2;无机肥施氮量767 kg/hm2;无机肥施氮量383 kg/hm2;有机肥施氮量450 kg/hm2,无机肥施氮量153 kg/hm2;有机肥施氮量300 kg/hm2,无机肥施氮量383 kg/hm2;有机肥施氮量150 kg/hm2,无机肥施氮量191 kg/hm2,研究了日光温室0～200 cm土壤中NH4+-N和NO3--N的迁移累积。结果表明,不同施肥模式主要影响0～40 cm土壤中NH4+-N的平均累积量和平均质量比,单施无机肥的相应值大于单施有机肥;不同施肥模式主要影响0～40 cm土壤中NO3--N的平均累积量和平均质量比,当施氮量小于383 kg/hm2时,相应值从大到小依次为:单施无机肥、单施有机肥、有机肥和无机肥配施,不同施肥模式也影响40～160 cm土壤中NO3--N的迁移累积。从地下水污染风险和产量考虑,北京农业种植区日光温室油菜种植可按照有机肥150 kg/hm2、无机肥191 kg/hm2的施肥模式进行施肥。     

肝癌细胞系中Runx3基因表达及启动子区异常甲基化分析

目的：通过检测6种肝癌细胞中Runx3基因异常甲基化状态及表达情况,探讨药物5-aza-2＇-deoxycytidine（decitabine）激活Runx3基因重新表达的能力及对肝癌细胞生长的影响。方法：采用DNA甲基化特异性PCR（MSP）技术分别对6种肝细胞癌细胞系Runx3基因启动子区域甲基化状态进行检测,同时采用逆转录一聚合酶链反应（RT—PCR）检测5种肝癌细胞中Runx3的表达情况及药物5-aza-2＇-deoxycytidine处理其中3种肝癌细胞前后Runx3表达变化。结果：6种肝癌细胞系中,有3种细胞Runx3基因启动子区域存在甲基化异常,药物5-aza-2＇-deoxycytidine处理3种肝癌细胞后,Runx3基因明显表达或表达活性增强。结论：启动子区异常甲基化是导致Runx3基因失活的主要原因之一,与肝细胞癌发生早期密切相关,可作为肝细胞癌早期诊断的分子标记物及分子治疗的靶点。     

土壤侵蚀遥感快速调查中有关技术问题的商榷

应用RS,GIS,GPS进行土壤侵蚀快速调查是将高新技术应用于生产实践的有益尝试,也是"3S"技术在水土保持中应用研究的前沿。土壤侵蚀调查是一项十分繁复的任务。在总结历次遥感侵蚀调查经验的基础上,针对第3次土壤侵蚀遥感调查中存在的有关技术问题,如信息源问题、土地利用定性参考层中存在的问题及技术路线中存的问题等进行了分析,并提出了相应的建议与同行商榷,供决策层参考。     

早熟丰产苦瓜长丰3号的选育

长丰3号苦瓜是汕头市白沙蔬菜原种研究所用C99-01A作母本、C01-03B作父本配制而成的杂交一代组合。果实长圆锥形,瓜长25～30cm,横径6～8cm,皮绿色,单瓜质量300～600g。中抗白粉病、枯萎病,耐热、耐寒、耐涝性强,适应性广。早熟,播种至初收春季为75天,夏秋直播后52天始收,每667m2产量3000～4000kg。     

渭北旱塬区不同栽培模式对小麦产量与土壤水分及硝态氮累积的影响

渭北旱塬小麦生产中需要克服的主要限制因子是水分不足,寻求合理的栽培措施以提高天然降水的利用率对于产量提高具有重要意义.本试验通过2a大田试验,研究了不同栽培措施对冬小麦产量及0～200 cm土层水分与硝态氮累积的影响.结果表明:(1)推荐施肥+垄上覆膜+沟内覆草(NP+ PF+ S)与推荐施肥+垄上覆膜(NP+ PF)两种垄沟栽培模式,虽然单位面积穗数明显降低,但由于穗粒数、千粒重显著高于其它栽培模式,因此产量和水分利用效率在所有模式中为最高.(2) NP+ PF+S和NP+ PF模式在小麦生育期内明显增加了土壤储水量,尤其在冬小麦易遭水分胁迫的时期(3-5月),其土层中储水量要明显高于其他模式.(3)土壤中硝态氮的累积主要集中在60cm以上,随着土壤深度的增加,累积量逐渐减少.在第二季,塬面冬小麦NP+ PF+S处理的硝态氮累积显著高于其它处理.在梯田,NP+S处理出现明显累积.由此可见,推荐施肥+垄沟栽培模式虽然促进土壤中氮素的累积,但是显著提高降水的有效贮蓄,是渭北旱塬区雨养农业条件下维持冬小麦高产的合理栽培模式.     

AgNO3对银杏胚愈伤组织诱导及分化的影响

为探讨AgNO3对不同发育期银杏胚愈伤组织诱导及分化的影响,以银杏3个不同发育程度合子胚为外植体,添加0～5 mg/L AgNO3做处理。结果表明：AgNO3能显著提高胚的愈伤诱导率：早期心形胚鱼雷形胚,早期子叶胚,成熟胚子叶分别在浓度1,0．5,0．1 mg/L时达到最大诱导率,为87％,77％,98％。隔代添加AgNO3促进了早期子叶胚愈伤的分化：1．0 mg/L处理在第90天分化出愈伤化银杏叶和胚类似物,3．0 mg/L处理分化出短小叶片;常规添加AgNO3的处理在0．1 mg/L分化出芽点。遮光处理表明：黑暗培养对愈伤诱导率影响不明显;添加活性炭时,AgNO3促进胚轴愈伤而抑制子叶愈伤,胚轴愈伤组织白色透明。综合分析表明：AgNO3能提高银杏胚的愈伤组织诱导率并促进其分化。     

农业信息技术的发展与应用前景

本文从我国农业信息技术的发展历史着手,介绍了国内外农业信息技术的发展概况和我国农业信息技术取得的成果,探讨我国目前农业信息技术发展存在的问题及发展模式,最后提出了未来农业信息技术的热点。     

改进的氨水法提取活性污泥中聚-3-羟基丁酸酯的试验

改进的氨水法提取活性污泥中聚-3-羟基丁酸酯(poly-3-hydroxybutyrate,PHB)的实验表明：提取率为63．65％．纯度为95．59％(w)。它是一种对环境污染较小,成本较低的提取方法。     

Respiration and Growth of Sorghum and Sunflower under Predicted Increased Night Temperatures1

Little information exists concerning how crops will respond to the predicted increased night temperatures. The objective of this work was to determine if respiration and growth of sorghum [Sorghum bicolor (L.) Moench], a C, plant, and sunflower (Helianthus annuus L.), a C₃ plant, are affected when the night temperature is increased by 5°C compared to the long-term (19 year) average night temperature in June in Kansas. Sorghum and sunflower were grown in two walk-in growth chambers with either the ambient night temperature (21C) or a high night temperature (26C). Day temperature was the same for all plants (27C). Both sunflower and sorghum had higher respiration rates under the elevated night temperature than under the ambient temperature. The average respiration rate of sunflower grown under elevated night temperature increased by 19% (0.89 vs. 0.75 μmol m^?2 s^?1) and that of sorghum by 44 % (0.52 vs. 0.36μmol m^?2s^?1). After 74 days, sunflower plants grown under the ambient night temperature were 30.2 cm taller than sunflower plants grown under the elevated night temperature; sorghum plants under the ambient temperature were 24.8 cm taller. Sunflower plants grown under the elevated night temperature formed flowers one week earlier than those grown under the ambient temperature. Sorghum formed no flowers by 74 days. Results suggest that, if climate change does increase night temperature, respiration will be increased more in C₄, than C₃ plants.