A modified fluorometric method to quantify the concentration effect (pI₅₀) of photosystem II-inhibiting herbicides     

Masaki Hiraki  Wim J. Vredenberg  Jack J.S. van Rensen  Ko Wakabayashi 《Pesticide biochemistry and physiology》2004,80(3):183-191

Chlorophyll fluorescence induction curves of isolated thylakoids were measured in the absence and in the presence of various concentrations of photosystem II-inhibiting herbicides. A mathematical program was applied to simulate the curves. Based on these simulated curves a new method is developed to determine the concentration effect (pI₅₀) of the herbicides. The results of the new method correspond well with reported values in the literature. The method is very convenient and time-saving.  相似文献   

Evaluation of the use of midazolam as a co‐induction agent with ketamine for anaesthesia in sedated ponies undergoing field castration          下载免费PDF全文

A. Allison  R. Robinson  C. Jolliffe  P. M. Taylor 《Equine veterinary journal》2018,50(3):321-326

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关于PA-250感应电机效率提高的研究     

喻佩佩 《湖南农机》2014,(8)

随着社会经济的飞速发展,对于节能环保的要求越来越高,传统的G/M代码已经成为现代先进制造技术的瓶颈。而基于STEP标准的STEP-NC将为现代CNC的高速和高精度加工提供条件。  相似文献   

农用有机硅助剂对全雌性旱黄瓜诱雄效果影响的研究     

刘思宇  刘剑辉  詹云  李岩  贾云鹤  王琳  刘琦  徐健  蒋欣梅 《中国林副特产》2014,(6):17-20

以全雌性旱黄瓜品种为试验材料，研究不同化学药剂（赤霉素、硝酸银、硫代硫酸银）及其不同使用浓度，结合有机硅助剂，分别两次处理4叶期、6叶期雌性系黄瓜幼苗，以每种诱雄药剂不加有机硅助剂为对照，观察各处理植株前15节的诱雄效果。结果表明，三种药剂均能够在一定程度上起到诱导雄花的效果，但是相同浓度下加入有机硅处理的各组叶片伤害程度较轻，采种量也较大，效果最好的组合是300mg／L硝酸银加有机硅助剂的一组。  相似文献   

Mapping soil salinity and pH across an estuarine and alluvial plain using electromagnetic and digital elevation model data     

J. Huang  V. N. L. Wong  J. Triantafilis 《Soil Use and Management》2014,30(3):394-402

Increasing pressures from agriculture and urbanization have resulted in drainage of many floodplains along the eastern Australian coastline, which are underlain by sulphidic sediments, to lower water tables and reduce soil salinity. This leads to oxidation of the sediments with a rapid decline in pH and an increase in salinity. Accurately mapping soil salinity and pH in coastal acid sulphate soil (CASS) landscapes is therefore important. One required map is the extent of highly acidic (i.e. pH < 4.5) areas, so that the application of alkaline amendments (e.g. lime) to neutralize the acid produced can be specifically targeted to the variation in pH. One approach is to use digital soil mapping (DSM) using ancillary information, such as an EM38, digital elevation models (DEM – elevation) and trend surface parameters (east and north). We used an EM38 in the horizontal (EM38h) and vertical (EM38v) modes together with elevation data to develop multiple linear regressions (MLR) for predicting EC_1:5 and pH. For pH, best results were achieved when the EM38 EC_a data were log‐transformed. By comparing MLR models using REML analysis, we found that using all ancillary data was optimal for mapping EC_1:5, whereas the best predictors for pH were north, log‐EM38v and elevation. Using residual maximum likelihood (REML), the final EC_1:5 and pH maps produced were consistent with previously defined soil landscape units, particularly CASS. The DSM approach used is amenable for mapping saline soils and identifying areas requiring the application of lime to manage acidic soil conditions in CASS landscape.  相似文献   

Dose requirement and cardiopulmonary effects of diluted and undiluted propofol for induction of anaesthesia in dogs     

Hanna Rögels  Fernando Martinez-Taboada 《Veterinary anaesthesia and analgesia》2021,48(2):247-251

ObjectiveTo compare the dose, cardiopulmonary effects and quality of anaesthetic induction in dogs using propofol (10 mg mL^–1) and diluted propofol (5 mg mL^–1).Study designRandomized, blinded, clinical study.AnimalsA total of 28 client-owned dogs (12 males/16 females).MethodsFollowing intramuscular acepromazine (0.02 mg kg^–1) and methadone (0.2 mg kg^–1), propofol (UP, 10 mg mL^–1) or diluted propofol (DP, 5 mg mL^–1) was administered intravenously (0.2 mL kg^–1 minute^–1) by an anaesthetist unaware of the allocated group to achieve tracheal intubation. Sedation, intubation and induction quality were scored from 0 to 3. Pre- and post-induction pulse rate (PR), respiratory rate (f_R) and systolic (SAP), mean (MAP) and diastolic (DAP) arterial blood pressure were compared. Time to first breath and induction dose were recorded. Data were analysed for normality and Mann–Whitney U or Student t tests were performed where appropriate. Significance was set at p < 0.05. Data are presented as mean ± standard deviation or median (range).ResultsThe propofol dose administered to achieve induction was lower in the DP group (2.62 ± 0.48 mg kg^–1) than in the UP group (3.48 ± 1.17 mg kg^–1) (p = 0.021). No difference was observed in pre- and post-induction PR, SAP, MAP, DAP and f_R between groups. The differences between post-induction and pre-induction values of these variables were also similar between groups. Time to first breath did not differ between groups. Sedation scores were similar between groups. Quality of tracheal intubation was marginally better with UP 0 (0–1) than with DP 1 (0–2) (p = 0.036), but overall quality of induction was similar between groups [UP 0 (0–1) and DP 0 (0–1), p = 0.549].Conclusion and clinical relevanceDiluting propofol reduced the dose to induce anaesthesia without significantly altering the cardiopulmonary variables.  相似文献   

陆地棉一个丝氨酸/苏氨酸激酶蛋白基因的克隆与表达分析   总被引：3，自引：1，他引：3  

杨郁文  倪万潮  张保龙  沈新莲  张香桂  徐英俊  姚姝 《棉花学报》2006,18(3):140-144

通过RT-PCR获得一个编码棉花丝氨酸/苏氨酸激酶类似蛋白全长的cDNA片段,其编码的氨基酸序列与拟南芥ATPK3的相似度达到82%,这个基因暂被命名为GhPK1。基因全编码区包括1038个核苷酸,编码346个氨基酸的蛋白。GhPK1的编码产物在265~270个氨基酸处有一个跨膜区并可能结合在内质网膜上。GhPK1在种子和纤维中的表达水平较其它组织高。另外,GhPK1的表达量在受到盐胁迫后上升,说明GhPK1可能参与了盐胁迫反应。  相似文献   

桃芽休眠诱导过程中IAA、ABA含量及PpPINs基因表达的变化     

贾楠  田航  彭竹君  王忆  吴婷  张新忠 《中国农学通报》2015,31(25):100-106

为认识桃芽休眠诱导过程中生理与相关基因表达的变化,分别用HPLC检测‘中农红久保’、‘中农3号’、03-30-035 3个桃品种(系)休眠诱导时期叶片和叶芽IAA和ABA含量,用RT-q PCR检测叶片和叶芽生长素极性运输载体基因Pp PIN1、Pp PIN3、Pp PIN5和Pp PIN8共4个基因的相对表达量。结果表明,在桃芽休眠诱导过程中,叶片IAA含量未见显著变化,ABA含量自10月6日开始升高,至10月16日含量达到高峰;叶芽中10月上中旬IAA含量骤增,而ABA含量逐渐降低。本研究中桃基因组的4个Pp PINs基因家族成员中,叶片中活跃表达为Pp PIN5,其次为Pp PIN3,在10月上中旬Pp PIN5出现强烈表达;而在10月26日,叶芽中活跃表达的Pp PIN1和Pp PIN3表达量骤降。桃休眠诱导过程中叶片和叶芽内内源激素和Pp PINs基因表达量变化明显不同。  相似文献   

高粱不同外植体离体培养   总被引：21，自引：3，他引：21  

白志良  王良群 《华北农学报》1995,10(1):60-63

不同材料愈伤组织诱导培养结果表明，幼穗，茎尖和成熟胚的最高出愈率达１００％，子粒达９３％，幼胚仅为７４％。幼穗不但出愈率高，且愈伤组织胚性状况好，分化出苗率高。幼胚出愈率虽低，但其分化率明显主茎尖，成熟胚和子粒了的分化率。  相似文献   

马铃薯双单倍体诱导及辅助育种研究进展     

白继鹏  王洪洋  李灿辉 《中国瓜菜》2021,(4):1-7

马铃薯(Solanum tuberosum L.)是继水稻、小麦、玉米之后全球第四大粮食作物。然而生产上种植的马铃薯多为四倍体普通栽培种,且由于其复杂的四体遗传和高度杂合的基因组等因素,严重阻碍了马铃薯遗传育种和品种改良的进程。人工诱导方法尤其是孤雌生殖诱导产生马铃薯双单倍体是解决上述问题的有效途径。马铃薯双单倍体不仅有助于普通栽培种马铃薯遗传改良,而且还可以二体遗传模式进行农艺性状遗传解析。概述了马铃薯双单倍体的育种应用、诱导方法、影响因素、鉴定方法等方面的研究进展,同时探讨了马铃薯双单倍体诱导的研究方向。  相似文献