In order to enhance the tolerance of rapeseed respond to low nitrogen（N） stress, this study investigated the effects of melatonin（MT） on N absorption and transport of rapeseed at the seedling stage under N deficiency conditions. The effects of exogenous application of MT on biomass, N uptake and accumulation, as well as the expressions of genes（BnNRT2s and BnAMTs） involved in N absorption and transport were analyzed by pot experiments. Results showed that, exogenous spraying of MT under N deficiency conditions significantly improved the shoots and roots biomass of rapeseed, especially when MT was sprayed at a concentration of 100 μmol/L. And exogenous spraying of MT also significantly increased N accumulation of shoots and roots of rapeseed seedlings. Further analysis found that, expression levels of BnNRT2.1s gene members（except BnNRT2.1a）, BnNRT2.2a, and BnNRT2.4b were up-regulated and reached the highest in roots when MT concentration was 100 μmol/L. And BnNRT2.7s and BnNRT2.5s were up-regulated and reached the highest in leaves when MT concentration was 50 μmol/L（MT50）. Meanwhile, the expression of BnAMT1.1a, BnAMT1.3b, BnAMT1.3c, BnAMT2.2a and BnAMT2.2c genes were significantly up-regulated in junior leaves, senior leaves and roots after exogenous application of MT. The expression of BnAMT1.4a, BnAMT1.4b, BnAMT2.1b, the abundance of BnAMT2.2a and BnAMT2.2b genes were also significantly enhanced in junior and senior leaves. Additionally, except BnAMT1.3b and BnAMT1.3c, all the above genes were expressed at the highest level under MT50 treatment. In conclusion, exogenous spraying of MT might improve N absorption and transport limited N to shoot through enhancing the expression of several BnNRT2s and BnAMTs. Thus exogenous application of MT could promote N absorption and utilization in rapeseed, alleviate low N stress and improve its low N tolerance.

为探究氮、镁胁迫对油菜苗期养分累积及氮同化途径的影响,以油菜品种中双11为材料,通过营养液设置正常对照(CK)、低氮(-N)、低镁(-Mg)和低氮低镁(-N-Mg)4个处理,分析氮、镁胁迫对油菜苗期氮、镁吸收累积及氮同化关键酶活性的影响及差异.结果表明:氮、镁缺乏显著抑制油菜苗期地上部生长,与对照相比,-N、-Mg和-N-Mg 3种处理地上部生物量分别显著降低68.49％,35.49％,69.71％.-N处理刺激根系生长,根冠比显著增加;-Mg处理抑制根系生长,根冠比显著降低.并且氮、镁交互对油菜氮、镁吸收累积均有显著影响,-N处理油菜根部镁含量及累积量显著增加,而-Mg处理油菜地上部氮含量及累积量显著降低;缺镁会导致油菜NH4+含量显著提升,并且-N-Mg对油菜氮、镁吸收累积影响的主要效应来自氮的缺乏.进一步比较不同处理下氮同化关键酶活发现,与对照相比,-N处理油菜新叶、老叶中NR、GS活性均显著降低,根部NR、GS和GOGAT活性均显著降低;-Mg处理GS活性也显著下降,但是降幅小于-N处理,而NR和GOGAT活性显著升高.综上所述,氮、镁缺乏对油菜苗期氮、镁积累存在交互作用,低氮胁迫会降低油菜苗期氮的吸收积累继而抑制植株氮同化;低镁胁迫可以通过提高铵态氮、NR和GOGAT活性来促进氮在无机氮间以及无机氮向有机氮的同化.

文章对国家标本标本资源共享平台(National Specimen Information Infrastructure,NSII)近15年来积累的植物数字化资源(植物标本数字化、彩色照片、植物志书等文献资料)进行统计分析,特别给出了标本数字化薄弱地区、标本记录空白区、标本空白科属、彩色照片空白科属名录,通过对外公开薄弱和空白区的方式,呼吁更多专业人员共建我国植物资源的数字化数据库(标本、彩色照片、文献).进而提出NSII未来发展的几点思考:(1)进一步整合数字化标本资源,加强薄弱地区、薄弱科属的标本数字化工作,整合在线的国内外数字化标本资源;(2)优化彩色照片库的管理模式,加强薄弱科属的彩色照片建设工作;(3)鼓励市县级植物志的编纂及地方性植物图鉴、不同类型植物志书的出版,从不同的角度丰富植物资源的资料.(4)深入清理数据,有效推动数据服务;(5)盘活NSII数据存量,打造更多的数据产品;(6)提升可视化水平,加强数据深度挖掘,更好服务科研和科普工作.

According to the requirement of infrared missile detecting system,a design scheme to extract data from missile plume graphics based on Matlab is presented.The scheme implements data extraction of missile plume and smooth the curve to reduce errors by interpolation and fitting.The analyzed results demonstrate the extracted data is reliable and can be used in the computation of missile plume defense systems.The design scheme is convenience and can also be used in any graphics which including axis and curve.

Aiming at geosynchronous orbit infrared detection system,the infrared detection performance of the ballistic missile plume is analyzed.The atmospheric transmittance and the background radiance at different heights and different sun zenith angles were computed with the atmospheric radiance model software of PCModWin.According to the obtained results,the performance indexes of infrared system for the plume detection of the ballistic missile,including the effective range,SNR(signal-to-noise ratio) and SCR(signal-to-clutter ratio),were analyzed.The results indicate that SCR performance index can meet the needs of the infrared detection system,but the performance of SNR and the effective range are not satisfactory.The performance of the infrared detection system can be improving the parameters of the sensors and the optical system.

A group of thermophilic microorganisms were isolated from the mud with a tempreture of 40~85℃.By extracting the genomic DNA and sequencing randomly,we found there was very high identity between these sequences and the genomic sequence of Thermus bacteria.According to the putative acid phosphatase gene sequence(TTHA1616)of Thermus thermophilus HB8 from Genbank,we designed primers and amplified the sequence by PCR.A 798 bp DNA sequence with putative entired acid phosphatase conserved domain,98% similar to that of TTHA1616 from Thermus thermophilus,was gotten.Then we expressed it in E.coli,and got a 33KD protein which we deduced that it had the activity of acid phosphatase.