1株库蠓源版纳病毒的分离与全基因组序列分析

为分析云南省虫媒病毒的种类与遗传特征,在云南省师宗县采集库蠓进行病毒的分离与鉴定;通过全长cDNA扩增与高通量测序技术获取病毒全基因组序列,进行序列比对与系统发生树构建。结果显示,从采集的库蠓样本中分离出1株可在C6/36细胞上引起细胞病变的毒株（YNSZ043）,病毒基因组为分节段双链RNA,琼脂糖凝胶电泳呈"2-4-3"的带型特征;电镜观察可见直径为70~80 nm,呈"指环状",表面具有纤维突起的病毒粒子。全基因组测序结果显示,YNSZ043毒株为版纳病毒（Banna virus,BAV）,基因组大小为20 683 bp,由Seg-1（3 762 bp）至Seg-12（861 bp）12个基因节段组成,与中国BAV毒株各基因节段的核苷酸序列相似性在64.8%~99.6%之间,氨基酸序列相似性在58.8%~100%之间,在系统发生树上YNSZ043毒株与中国分离的BAV聚为一簇,形成独立的中国进化支系。对决定BAV基因型的Seg-12分析结果显示,YNSZ043毒株属于A2基因型,该毒株的Seg-5/VP5与越南分离BAV毒株的核苷酸和氨基酸序列相似性高达97.1%和97.6%,表明该毒株的Seg-5基因节段很可能与越南毒株之间发生了基因重配。研究结果丰富了中国BAV的基因组序列,为开展云南省BAV的流行病学研究提供了参考。     

Accuracy of genomic prediction using imputed whole‐genome sequence data in white layers

There is an increasing interest in using whole‐genome sequence data in genomic selection breeding programmes. Prediction of breeding values is expected to be more accurate when whole‐genome sequence is used, because the causal mutations are assumed to be in the data. We performed genomic prediction for the number of eggs in white layers using imputed whole‐genome resequence data including ~4.6 million SNPs. The prediction accuracies based on sequence data were compared with the accuracies from the 60 K SNP panel. Predictions were based on genomic best linear unbiased prediction (GBLUP) as well as a Bayesian variable selection model (BayesC). Moreover, the prediction accuracy from using different types of variants (synonymous, non‐synonymous and non‐coding SNPs) was evaluated. Genomic prediction using the 60 K SNP panel resulted in a prediction accuracy of 0.74 when GBLUP was applied. With sequence data, there was a small increase (~1%) in prediction accuracy over the 60 K genotypes. With both 60 K SNP panel and sequence data, GBLUP slightly outperformed BayesC in predicting the breeding values. Selection of SNPs more likely to affect the phenotype (i.e. non‐synonymous SNPs) did not improve the accuracy of genomic prediction. The fact that sequence data were based on imputation from a small number of sequenced animals may have limited the potential to improve the prediction accuracy. A small reference population (n = 1004) and possible exclusion of many causal SNPs during quality control can be other possible reasons for limited benefit of sequence data. We expect, however, that the limited improvement is because the 60 K SNP panel was already sufficiently dense to accurately determine the relationships between animals in our data.     

OPTIMAL DESIGN WITH WHOLE STRUCTURE PARAMETERS OF LOWER PART OF HUGE EXCAVATOR

A optimal design with whole structure parameters and its program are carried out. A reasonable model is established. Using the method a optimal design with whole structure parameters by original parameters of American P&H2300xp excavator was calculated. The size,carried out by the method,approximates to the size of P&H2300xp excavator very well.     

旱地全膜双垄沟残膜捡拾机的设计

针对我国西北旱地全膜双垄沟残膜捡拾机仿形能力差、拾净率低的问题,设计了一种旱地全膜双垄沟滚筒式残膜捡拾机。同时,阐述了整机结构及工作原理,并通过机构分析和计算确定了关键部件工作参数,旨在为残膜回收提供一种新的机具。     

水稻旱作覆膜节水增产试验研究

通过水稻旱作全程覆膜与半程覆膜、旱作不覆膜及水栽对比试验，研究其耗水规律，计算其节水量与增产量，并进行经济效益分析，提出了适合本地区的栽培模式。     

双侧脑室引流、冲洗结合腰穿救治高血压脑出血破入全脑室患者的临床观察

目的 观察双侧脑室冲洗、引流结合腰穿治疗高血压脑出血破入全脑室的有效性和安全性.方法 将高血压脑出血破入全脑室的83例分成双管组(n=57)和单管组(n=26),双管组采用双侧脑室引流、冲洗结合腰穿的方法治疗(57例);单管组用单管引流治疗(26例),将两组治疗结果进行统计学分析和比较.结果 双管组:良好和中残35例(61.4%)、重残11例(19.3%)、植物生存2例(3.5%)、死亡9例(15.8%),单管组分别为6例(23.1%)、6例(23.1%)、1例(3.8%)、13例(50.0%),以双管组的疗效为优(P＜0.01);且双管组的病死率明显低于单管组(P＜0.01).双管组的脑脊液廓清时间为3～6(4.2±1.3)d,明显短于单管组的6～15(8.6±2.1)d(P＜0.01).结论 双管引流比单管引流更容易保持引流通畅,脑脊液廓清迅速,并发症减少,能降低病死率,提高生存质量,是一种安全、有效治疗全脑室出血的方法.     

覆盖方式对旱地马铃薯阶段耗水量特征和产量的影响

为明确不同覆盖方式对旱地马铃薯田土壤耗水、耗水规律、水分利用效率、产量及产量形成的影响,在陇中半干旱农区设置了玉米秸秆带状双行覆盖(SSM2)、玉米秸秆带状单行覆盖(SSM1)、玉米秸秆全覆盖(SFM)、地膜春覆盖(PMS)和地膜秋覆盖(PMA)5种覆盖方式,以传统露地平作为对照(CK)。结果表明:2年试验中,玉米秸秆带状覆盖和地膜覆盖处理土壤贮水消耗量较CK分别增加13.5,14.8 mm。玉米秸秆带状覆盖能显著提高降水对马铃薯耗水贡献率,不同降雨年型内均以SSM2处理贡献率最高,2年分别为95.6%和94.3%。于CK相比,覆盖处理均降低了生育前期(播种-块茎形成期)耗水量,地膜覆盖显著增加了生育中期(块茎形成期-淀粉积累期)耗水量,玉米秸秆带状覆盖显著增加了生育后期(淀粉积累期-收获期)的耗水量。玉米秸秆带状覆盖和地膜覆盖分别能使马铃薯干薯产量增加27.9%和24.2%,干薯水分利用效率提高23.1%和19.3%。综上可知,玉米秸秆带状覆盖处理能显著增加马铃薯生育时期内农田土壤贮水消耗量,并改善马铃薯生育前期和生育后期耗水,减少旱地马铃薯农田无效耗水,能显著提高马铃薯干薯产量和水分利用效率。     

玉米植株冠层截留分异特征及其影响因素

基于研究区实际降雨频率,采用人工模拟降雨法对玉米全生育期冠层截留量、茎秆流量和穿透雨量进行测定,分析叶面积和降雨强度对玉米植株冠层截留分异特征的影响。结果表明:不同生育期,玉米冠层截留率平均为8.42%,茎秆流率平均为35.38%,穿透雨率平均为56.19%;不同降雨强度,玉米冠层截留率平均为7.53%,茎秆流率平均为26.79%,穿透雨率平均为65.68%。冠层截留量、茎秆流量和穿透雨量与雨强呈极显著线性正相关关系,冠层截留量和茎秆流量与叶面积之间呈极显著正相关直线关系,而穿透雨量与叶面积之间呈极显著线性负相关关系。