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41.
ACC合酶cDNA克隆及其对美洲黑杨体内乙烯产生的反义抑制 总被引:1,自引:0,他引:1
利用RTPCR技术克隆了大豆ACC合酶基因GMCACCSI编码区15kb的cDNA片段,经酶切图谱分析和序列分析鉴定后,反向插入到2元载体pBin438中,构建了表达ACC合酶反义RNA的植物表达载体,转化农杆菌后用该农杆菌侵染美洲黑杨叶片,在含卡那霉素的MS培养基上选择转化子和植株再生,通过PCR检测从抗卡那植株中选到15株转基因植株,Southern杂交分析初步确证了外源基因是以单拷贝插入到杨树基因组DNA中;对杨树幼苗乙烯释放的测定结果表明转基因杨树幼苗的乙烯释放量为对照的22%。 相似文献
42.
巨胚水稻W025糙米浸水后γ-氨基丁酸含量变化的研究 总被引:16,自引:0,他引:16
富含γ-氨基丁酸(GABA)的降血压功能水稻正受到越来越多的关注。W025是通过化学诱变和杂交选育而成的水稻新品系,具有巨胚特征,遗传分析表明巨胚基因受单隐性基因控制。进一步研究W025和其原始品种金南风浸水后γ-氨基丁酸(GABA)含量及其合成关键酶——谷氨酸脱羧酶活性的动态,并用半定量RT-PCR检测了2个谷氨酸脱羧酶转录本在浸水过程的表达变化。结果表明,(1)GABA主要集中在胚部,浸水后W025的GABA积累量显著高于金南风。(2)随着浸水时间延长,谷氨酸脱羧酶(GAD)的活性呈逐渐增加趋势,W025胚部的酶活性显著高于金南风。GAD活性的变化与GABA的积累显著正相关,表明浸水后种胚GABA的积累与谷氨酸脱羧酶的催化反应有关。(3)2个谷氨酸脱羧酶基因OsGAD1与OsGAD2在W025和金南风之间没有转录水平的差异。提示可能存在其它的谷氨酸脱羧酶基因对浸水后GABA的积累起关键作用。 相似文献
43.
农业科技示范园区评价指标体系的设置与实证分析 总被引:10,自引:0,他引:10
从农业科技示范园区建设目标出发 ,在分析园区作用机制和大量实地调研的基础上 ,运用层次分析法 (analytichierararchyprocess)设置出农业科技示范园区的 4个层次共 36个具体评价指标 ;结合专家咨询法 (Delphi)测算出各层次指标的权重值 ;用该指标体系对两个园区做了具体评价分析 相似文献
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A general linear model (GLM) was used to standardize catch per unit effort (CPUE) data for Alaska walleye pollock (Theragra chalcogramma) from the Bering Sea fleet for the years 1995–1999. Data were stratified temporally by year and season and spatially by area using either Alaska Department of Fish and Game (ADF&G) or National Marine Fisheries Service (NMFS) reporting areas. Four factors were used: vessel identification (ID) number, vessel speed, percentage of pollock by weight in the haul (a measure of targeting), and whether most of the haul took place before or after sunset. At least 29 combinations of main effects, quadratic covariates, and interactions were tested for each year/area/season stratum. GLM models explained from 31 to 48% of the total sums of squares. Vessel identification number was included in all models and explained the most variability. Of the remaining factors, the square of the percentage of pollock in the haul was included in most models, following an F-test to determine parsimony. Analysis of the vessel identification number coefficients indicated that larger vessels tended to have higher CPUEs; and that this relationship differed between dedicated catcher vessels and offshore catcher processors. Coefficient estimates and response surfaces generally indicated increased CPUEs with the percentage of pollock in the haul and showed mixed results with vessel speed. The vessel identification number incorporated most vessel characteristics, leaving vessel speed primarily as a fitting variable with less biological meaning. The year/area/season stratification procedure was found to be necessary due to the unbalanced design, which otherwise would have factor levels with no data in a large combined model. In addition, the stratification procedure reduced the variability in CPUE substantially. 相似文献
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氮是植物和微生物生长繁殖的必需营养元素,而氮矿化表征了土壤供氮能力。通过盆栽实验,采用同位素稀释法和磷脂脂肪酸(PLFA)法,研究了添加硝化抑制剂和秸秆条件下,潮棕壤碳氮矿化和微生物群落组成变化特征。结果表明,与施氮量N 0.1 g·kg~(-1)的单施氮肥处理(NF)相比,氮肥配施1%硝化抑制剂(NFI)的土壤铵态氮提高32%,而硝态氮降低53%。氮肥与施用量为5 g·kg~(-1)的秸秆配施(NS),土壤氮素总矿化速率增加36%,微生物生物量碳提高51%,β-葡萄糖苷酶活性提高36%,同时显著增加了土壤总PLFA以及细菌、真菌、真菌/细菌和革兰式阴性菌(P0.05),土壤呼吸熵降低50%。与氮肥配施秸秆处理(NS)相比,氮肥、秸秆和硝化抑制剂配施处理(NSI),土壤铵态氮提高33%,硝态氮下降47%。综上所述,氮肥和秸秆配施可以提高土壤微生物生物量,改变土壤微生物群落组成,配施1%(N)硝化抑制剂后降低土壤硝化速率,增加土壤供氮能力。 相似文献
49.
Qing-Qin Cao Yi-Chen Jiang Xing-Liang Li Yuan-Yue Shen Yu Xing Ke-Feng Fang 《The Journal of Horticultural Science and Biotechnology》2013,88(6):726-732
SummaryRetrotransposons are major components of the genomes of most eukaryotic organisms and have resulted in the introduction of desirable traits in many crops, including fruit trees. Here, we describe a Ty3-gypsy-like retrotransposon associated with a short-catkin mutant in Chinese chestnut (Castanea mollissima), resulting in catkins that are < 20% the length of normal staminate catkins. A partial sequence of the retrotransposon, named CmRT1, detected by amplified fragment length polymorphism (AFLP) analysis, and its complete sequence were determined from the genome of Chinese chestnut (Castanea mollissima) using improved Tail-PCR. CmRT1 was 10,067 bp in length and shared high homology in its predicted amino acid sequence and motifs with other Ty3/gypsy-like retrotransposons. The 5’ long terminal repeat (LTR) of CmRT1 contained a TATA box and several cis-elements that were predicted to be important for processes involving abscisic acid, gibberellic acid, and auxins and in stress-mediated responses. Further characterisation of the transposition event that led to the short-catkin phenotype was performed using two pairs of primers that aligned with the flanking region of the LTRs. The expected PCR bands were observed only in genomic DNA from plants that showed the mutation. Finally, cloning and real-time qPCR analysis of an NADP-dependent alkenal double-bond reductase (CmADBR) target gene that was adjacent to CmRT1, revealed that CmADBR expression was significantly down-regulated in the short-catkin mutant. Taken together, these results suggest that the CmRT1 retrotransposon is responsible for the short-catkin phenotype. 相似文献
50.
泌乳奶山羊非繁殖季节诱发发情研究 总被引:2,自引:0,他引:2
奶山羊具有明显的季节性发情的特点,在非繁殖季节里,泌乳母羊体内的催乳素水平要高于繁殖季节,从而抑制了卵巢的生理机能。本研究采用具有抑制催乳素分泌作用的溴隐亭(CB-154,Parlodel)药物来降低母羊体内的催乳素水平,配合使用促性腺激素,提高泌乳母羊的诱发发情率,使配种后不返情率达到80%(28/35)。 相似文献