鸽痘病毒的分离与鉴定

鸽痘是由鸽痘病毒(Pigeonpox virus.pvv)引起的鸽的主要传染病Ⅲ.为研究PPV的致病性和免疫机理,更好的防制鸽痘,我们对南京市及周边地区感染鸽痘的鸽群进行了病原分离,得到了2株病毒,本试验对2个分离株作了详细的鉴定.     

汽车发电机电动势3次谐波分量的估算

分析了Y联接和Y0联接整流电路在畸变电动势作用时的中性点电压,给出了畸变电动势3次谐波分量的估算方法,并估算了Y0联接汽车交流发电机在中性点二极管导通时电动势中3次谐波分量的大小.     

甲基吡啶铬对生长肥育猪生产性能及胴体品质的影响

通过饲养试验和屠宰试验研究了甲基吡啶铬对生长肥育猪生产性能及胴体品质的影响。选择 4 8头平均体重为 3 0 .7± 3 .1kg的长白×大白×北京黑三元杂交健康生长猪 ,按单因子随机区组设计分为对照组和试验组 ,分别饲喂未加甲基吡啶铬的日粮和添加 0 .0 5 %甲基吡啶铬 (折算成铬的添加水平为2 0 0 μg/kg)的日粮。试验结果显示 :试验组平均日增重和平均日采食量与对照组无显著差异 ,但饲料转化率显著改善 1 0 .2 % (P <0 .0 5 ) ,屠宰率和瘦肉率分别提高了 2 .9%和 2 .0 % (P >0 .0 5 ) ,第 1 0肋和最后肋背膘厚度分别下降 1 .6%和 1 3 .0 % (P >0 .0 5 ) ,眼肌面积显著增加 1 3 .8% (P <0 .0 5 )     

生长调节剂在草坪上的应用

生长调节剂对草坪草有不同的功效。有的促进草坪草的生长 ,有的起抑制作用 ,并且对草坪草抗寒性的影响与草坪草类型有关。本文对这些作用进行了探讨。     

猪用中草药饲料添加剂组方筛选试验

试验采用单因子设计,54头断奶猪(长×荣,20kg左右)根据体重、性别随机分成6个处理组,每个处理3次重复,每次重复3头试验猪。结果表明:20～60kg阶段,平均日增重(ADG)Ⅰ、Ⅱ组显著高于Ⅳ组和抗生素组25.80%、26.03%和25.27%、25.49%(p<0.05)。增重/料耗(G/F)各处理间无显著差异,但中草药Ⅰ组、Ⅱ组、Ⅲ组较抗生素组有提高趋势。20～90kg整个生长育肥期分析,Ⅰ组显著高于抗生素组20.89%(p<0.05);G/F中草药组都比抗生素组有提高趋势,分别为7.48%、4.33%、6.30%、6.30%、0.78%(P>0.05)。     

Classification and Genetic Diversity of Three Hare Species in Xinjiang Based on Mitochondrial DNA

The study aimed to explore the phylogeny and genetic diversity of 3 hare species in Xinjiang by molecular genetics methods, define the relationship and taxonomy status, assess diversity level of Lepus in Xinjiang, and provide the basic data for conservation genetics of hares in Xinjiang and even in China. Three mitochondrial DNA genes, COI, ND4 and 16S rRNA, were used as molecular markers, and the sequences of 3 genes of 57 samples collected from 8 different regions (4 geographic groups) in Xinjiang were determined by PCR amplification and sequencing technology. After the sequences of COI, ND4 and 16S rRNA of each sample were revised and pooled together, data were analyzed with softwares such as MEGA 7, DNAsp 6, Arlequin 3.1 and MrBayes 3.2. A total of 43 haplotypes were detected from the combined sequences of 3 genes of 57 hare samples. Five distinct clades (A-E) and 3 clusters were clearly showed in phylogenetic tree and median-joining network (MJN). Furthermore, the genetic distance between 3 clusters reached the level of species (4.21%-9.09%). However, the genetic distance between hares from northern Xinjiang (Clade E) and those from central Xinjiang (Clade D) were not up to the level of species (≤2.26%) in the third cluster. The haplotype diversity (h) of Lepus yarkandensis, Lepus tibetanus pamirensis and Lepus tolai lehmanni were higher(0.979±0.014, 0.972±0.064 and 0.972±0.064, respectively), while the nucleotide diversity (π) of the L. t. lehmanni and L. t. centrasiaticus were higher (0.033±0.018 and 0.023±0.015, respectively). Based on comprehensive analysis of 3 genes of mitochondrion and reference with published research, it is suggested that hares from southwestern Pamir Plateau of Xinjiang should belong to L. t. pamirensis. Meanwhile,hares distributed in northern and central Xinjiang might be considered as L. t. lehmanni and L. t. centrasiaticus. Moreover, there is abundant genetic diversity in the 3 hare species in Xinjiang, and the obvious phylogeographic pattern is showed.     

外源茉莉酸甲酯对UV-B胁迫下颠茄生物碱积累及TAs代谢途径调控的机制探究

In order to preliminarily explore the mechanism of TAs metabolic pathway in A. belladonna treated with exogenous methyl jasmone under UV-B stress, the effects on the contents of hyoscyamine and scopolamine, the upstream products in alkaloid synthesis, signal molecule and the expression level of key enzyme genes of secondary metabolism were studied under different concentrations of exogenous MeJA and different treatment time under using A. belladonna as materials. UV-B stress treatment significantly reduced the contents of hyoscyamine and scopolamine, inhibited the accumulation of precursors in the TAs synthesis pathway, which harmful to TAs synthesis. The content of TAs in A. belladonna increased to some extent, the contents of precursor amino acids (ornithine, arginine), polyamine content and key enzymes activities in the synthesis of putrescine in the secondary metabolic pathway all increased to some extent after treatment with the appropriate concentration of MeJA. The concentrations of signal molecule NO firstly increased and then decreased with the rising MeJA concentration, and reached the highest when MeJA concentration was 250 μmol L ^-1. The expression of key enzyme genes in TAs synthesis pathway showed that exogenous MeJA could increase the relative gene expression levels of TR I, PPAR, H6H to some extent. Those indicated that exogenous MeJA could induce the increase in the contents of upstream products in TAs synthesis by stimulating the burst of NO resulted in more precursor materials for the TAs synthesis pathway and affect the high expression of TR I, PPAR and H6H. It alleviated the inhibiton of UV-B stress on TAs of A. belladonna and increased the contents of hyoscyamine and scopolamine effectively. The results provided a theoretical basis for further studying the mechanism of exogenous elicitors to regulate the TAs secondary metabolic pathway of A. belladonn under stress, and effectively improved the stress resistance of A. belladonn and the accumulation of medicinal ingredients in actual production.     

西北地区林业发展战略研究

论述了西北地区林业发展的战略思想、战略目标、战略重点,提出了西北地区林业发展的战略措施。对于促进西北地区林业发展,保护和建设该地区生态环境具有重要意义。     

陇东紫花苜蓿地上生物量及水分利用率分析

分析紫花苜蓿Medicago sativa地上生物量的变化表明:鲜、干质量曲线的增长特点是返青(萌芽)至现蕾后增长快,进入开花期后增长缓慢;第1茬鲜质量和干质量占全年总鲜质量和干质量的比例最大,高度与鲜质量和干质量的增长成正相关;在不同茬的生长期内,气象要素对其贡献不同,水分利用率以第2茬最高。     

河北省冬小麦生产干旱风险分析

利用河北省冬麦区49个气象站1980-2010年的气象资料及其相应的冬小麦产量资料,选取三种干旱指数,根据自然灾害风险分析的基本原理,计算了气候干旱、作物干旱、产量灾损三种风险度,并进行了相应的风险区划,根据区划结果提出了不同风险区的减灾对策.结果表明:(1)冬麦区气候干旱风险以中风险或较高风险区域为主,作物干旱风险则以较高风险区为主,产量灾损低风险区域较大.(2)气候干旱、作物干旱、产量灾损各等级风险区分布无明显相关关系,产量灾损风险与各地的灌溉条件关系密切.(3)产量灾损各风险区应采取不同的减灾对策,高风险区应以防旱为主,采取一系列保墒措施,提高自然水分利用率;较高风险区应以抗旱防旱为主,加强农田水利基本建设,改善灌溉条件;中低风险区应以发展优化灌溉制度为主,实现节水高产.