棉蚜羧酸酯酶同工酶cDNA片段的基因克隆与序列分析

采用简并引物和降落PCR技术,克隆了棉蚜2个羧酸酯酶同工酶基因的cDNA片段,分别命名为Ag.est1和Ag.est2。其中Ag.est1为479bp,编码160个氨基酸;Ag.est2为476bp,编码159个氨基酸。序列同源分析表明,PCR扩增获得的Ag.est1和Ag.est2基因与其他昆虫的羧酸酯酶具有较高的相似性。2个羧酸酯酶同工酶基因cDNA片段的GeneBank登录号分别为:AF502083、AF502084。     

Signal Processing of Electroencephalogram and It''s Application

Electroencephalogram (EEG) signals are the electrical activities in the cortex or on the surface of scalp caused by the physiological activities of the brain which play a key role in the diagnosis of brain and the functional determination of brain. The authors discuss some methods for processing EEG signals from the view of the frequency domain and time domain, especially introduce some time-frequency analysis methods such as Wigner distribution, wavelet transform and matching pursuit etc. , ANN and non-linear analysis for EEG signals processing.     

Standardisation of true cassava seed (TCS) programme with special emphasis on more homogeneous, CMD resistant progenies

The propagation of cassava through true seeds (sexual seeds) rather than by clones is a promising option due to its manifold advantages such as enhancing the multiplication rate, keeping the dreaded cassava mosaic disease (CMD) under check, longer seed viability, ease of storage and transport. The high genetic heterogeneity and consequent variation among seedlings is the major stumbling block in sexual propagation. In the present study, a CMD resistant exotic accession MNga-1 and a promising cultivar Ambakadan with profuse fruit setting, seed output and male sterility were identified to be promising parents for the TCS programme. The rate of sexual propagation could be more than 20-fold over the traditional clonal propagation. Seed treatment with 1% KNO₃ or 300 ppm GA promoted uniform seed germination and seedling vigour and reduced the transplanting period from 45 days after planting (DAS) to 30 DAS. Removal of taproots of seedlings while transplanting enhanced tuber development. Tuber yield of first clones (C₁) was significantly superior to that of the seedlings. The dry matter content and starch output of seedlings and first clones were comparable to that of the commercial varieties. Similarly, the HCN and cooking quality of seedlings and first clones were at acceptable levels. In the open pollinated (OP) progenies of the Ambakadan the CMD infection increased drastically due to secondary spread of the pathogen. The hybrid progenies of Ambakadan and the CMD resistant line MNga-1 revealed higher percentage of CMD free seedlings and first clonal progenies in the evaluation trials conducted at CTCRI Thiruvananthapuram and ARS, Peddapuram during 2001–2002 and 2002–2003. Nearly homogeneous hybrid population resistant to CMD could be obtained by systematic roguing at seedling and first clonal stage.     

Allelic variation, sequence determination and microsatellite screening at the XGWM261 locus in Chinese hexaploid wheat (Triticum aestivum) varieties

Wheat microsatellite XGWM261, due to its closely linked to the dwarfing gene Rht8, has been adopted as the diagnostic molecular marker of Rht8. Screening 408 Chinese and 98 exotic varieties showed 13 allele variants in locus of XGWM261, with 6 alleles only to be found in Chinese varieties and 2 only in exotic varieties, respectively. Sequencing results of the 13 alleles revealed their absolute fragment sizes with 216, 212, 210, 206, 204, 202, 200, 196, 194, 192, 190, 174, and 164 bp, respectively. Allelic distribution analysis showed that the 204, 192, 174, and 164 bp alleles were prevailing in Chinese varieties, and the diagnostic 192 bp allele to Rht8 had a very high percentage in the Yellow and Huai River Valleys Facultative Wheat Zone than in the Northern Winter Wheat Zone in China. The GT → AC substitution at position 35 was found in 216, 200, and 174 bp alleles. Moreover, the AG insertion immediately at the end of CT-repeat region was also found in 216, 200, 174, and 164 bp alleles.     

回交高代选择导入系的纹枯病抗性与抗旱性的遗传重叠研究

利用来自抗旱性较好的供体亲本（BG300和BG304）、具有两种遗传背景（IR64和特青）的水稻高代回交（BC2）抗旱选择导入系，通过人工接种的方法鉴定纹枯病抗性，考察纹枯病抗性与抗旱性之间可能存在的遗传重叠。通过与受体亲本的纹枯病抗性表现比较发现，具有特青背景的抗旱选择导入系倾向于纹枯病抗性的降低，而IR64背景的抗旱选择导入系则倾向于纹枯病抗性的增强。基于基因型与表型的方差分析共鉴定到6个与纹枯病抗性相关的位点，其中QSbr6在不同供体和背景的两个群体中分别检测到，而QSbr10则在同一供体的两个遗传背景下均检测到；有3个位点（QSbr6、QSbr8和QSbr10）与同一群体中检测到的抗旱性位点位置相近，很可能是两种抗性重叠的遗传基础。尽管方差分析的方法在选择导入系的非选择目标性状相关位点的鉴定中存在相当程度的偏低估计，本研究所检测到的纹枯病抗性位点，特别是那些与抗旱性重叠位点的分子标记以及相关的抗性株系仍将为进一步的水稻纹枯病抗性和抗旱性的多抗性育种和深入的遗传重叠研究提供有用的信息和材料。     

Analysis About the Coupling Circuit of the Communication With Low-voltage Power Line

In the interest of realizing carrier communication using LVPL, it is sticking point to analyse and design the coupling circuit of the communication. Higher efficiency of loading carrier signals is necessary. On the other hand, disturbs from LVPL should be overcome. Penman commendably resolved the difficult problem with the "complex-coupling-technology" of combining " electromagnetism - coupling" to "RC-coupling". Based on the " complex - coupling-technology" , "the interface circuit of the communication is analyzed and designed with LVPL. Simulation results and experimentation results show : the coupling circuit not only has higher efficiency of loading carrier signals but also can completely close off 50 Hz signal from LVPL. Therefore, the coupling circuit can apply to communication systems on LVPL.     

棉花DUS测试标准品种的SSR指纹数据库构建

基于SSR核心引物,采用荧光毛细管电泳检测系统与多重PCR技术相结合,构建我国棉花DUS(Distinctness,Uniformity and Stability)测试标准品种的DNA指纹数据库并进行遗传多样性分析。依据多重PCR组合的基本原则与五色荧光检测系统的特点,采用40对核心引物构建了10个4重PCR组合,利用DNA遗传分析仪进行指纹检测与数据采集。40对荧光引物在30份DUS测试标准品种中共扩增产生146个等位变异,每对引物的等位变异数为2~7个不等,平均每对引物产生3.65个等位变异。海7124与陆地棉品种明显划分为2类,来源于新疆的新陆早1号区别于其他陆地棉品种,单独聚为1类。多色荧光检测系统相比常规聚丙烯酰胺凝胶电泳具有高精度、高通量、自动化程度高的优点,尤其适用于大规模指纹数据库的构建,提出了通过构建已知品种DNA指纹数据库,将分子标记技术应用于棉花DUS测试的初步设想。     

温度湿度及种球茎大小对花魔芋有性繁殖的影响

有性繁殖是促进魔芋种植业发展和品种改良的有效途径，引起了极大的兴趣。本文研究117个花魔芋（Amorphophallus konjac K. Coch)单株花粉成熟后连续5d的温度、湿度以及花芽种球茎对其有性繁殖的影响，结果表明：授粉期间的温度和湿度对其自花授粉结实影响大，结实株花粉成熟后连续5d的平均温度和湿度分别为24℃和64%，均显著高于不实株，高温高湿有利于散粉和花粉的萌发从而完成受精；花芽种球茎大小对有性繁殖也有影响，结实株平均种球茎重显著高于不实株，且与单株结实浆果数呈极显著的正相关（r=0.6096, N=29），因此，宜选用花芽球茎大的用于魔芋有性繁殖。     

夏玉米施氮量对后茬冬小麦土壤氮素供应与利用的影响

在冬小麦施氮144 kg/hm2的基础上,研究了夏玉米4个施氮量(0,90,180,270和360 kg/hm2)对后茬冬小麦生长期间土壤硝态氮含量变化、无机氮供应以及小麦氮素吸收与利用的影响。结果表明:与玉米不施氮(简称不施氮)相比,玉米施氮(简称施氮)0~200 cm土壤硝态氮含量在冬小麦生长期间显著增加,自冬小麦拔节起,0~40,0~130和0~200 cm 3层深的土壤硝态氮含量均随着玉米施氮量(简称施氮量)的增加而明显递增;与冬小麦播种时相比,不施氮0~130 cm土壤无机氮减少156 kg/hm2,施氮90 kg/hm2该层土壤无机氮富积41 kg/hm2,且富积量随着施氮量继续增加而递增;随着施氮量增加,冬小麦收获时的植株吸氮量和子粒氮素积累量均增加;当施氮量低于180 kg/hm2时,植物氮素积累量在不同施氮量之间无显著差异;当施氮量低于270 kg/hm2时,不同施氮量的子粒氮素积累量差异不明显。在本试验条件下,冬小麦子粒氮肥利用率随着施氮量增加而递增,但差异不显著。     

10个紫花苜蓿品种耐盐性的比较研究

对10个紫花苜蓿品种种子分别用0%、0.3%、0.7%和1.0%的NaC l溶液进行处理,通过种子发芽率、相对发芽势、幼苗重和幼苗高对各品种种子萌发期耐盐性进行了研究。结果表明:用0.7%或1.0%NaC l溶液性鉴定较为合理;0.7%NaC l溶液处理苜蓿种子,其幼苗重和幼苗高可作为苜蓿品种耐盐的鉴定指标。0.7%、1.0%NaC l溶液处理下,通过测定第3天和第5天各品种种子的发芽势,可以鉴定耐盐性大小。对10个苜蓿品种耐盐性综合研究结果是:龙牧801和巨人201的耐盐性最强,其次是肇东、龙牧803和CW 200;新疆大叶和爱菲尼特的耐盐性最弱。