青海省泽库县草地现状与畜牧业可持续发展对策

在综述泽库县草地退化现状的基础上,综合分析了草地退化的原因,提出了畜牧业可持续发展的策略.泽库县的草地退化是自然因素和人为因素综合作用的结果.人类活动和气候变化是导致泽库县草地退化、区域生态环境恶化的两大因素,鼠虫害对它们产生的影响起了促进作用.只有合理利用和保护天然草地,优化产业结构,使草地生态系统步入良性循环,才能使泽库县的草地畜牧业协调发展.     

Effects of CpG-B ODN on the protein expression profile of swine PBMC

The CpG motif within bacterial DNA is a potent immuno-stimulatory moiety. Here, using a 2-D electrophoretic approach, we investigated the effect of synthetic oligodeoxynucleotide containing a B type CpG motif (CpG-B ODN) on the protein expression profile of swine peripheral blood mononuclear cells (PBMC). We found that several proteins including spondin 1, N-acetolactate alpha linked acidic dipeptidase; V kappa light chain, T cell receptor variable alpha chain, heat shock protein (Hsp) 60, Hsp70, KIAA0857 protein, and PNAS-146 were up-regulated in PBMC by CpG-B ODN stimulation. Further studies showed that CpG-B ODN-mediated Hsp60, Hsp70 and Hsp90 expressions were closely associated with the TLR9 signalling pathway. Pretreatment with inhibitors of Hsp70, Hsp90 and TLR9 all blocked the CpG-B ODN-mediated anti-apoptotic effect in swine PBMC. These results suggest that CpG-B ODN treatment of swine PBMC may enhance the expression of biologically active proteins, notably spondin 1, V kappa light chain, T cell receptor variable alpha chain and Hsps, which may play an important role in CpG-B ODN-mediated activation of immune responses and enhancement of swine PBMC survival.     

Characterization,phylogenetic analyses and pathogenicity of Bipolaris setariae associated with brown stripe disease on sugarcane in Yunnan,China

Brown stripe disease is a severe foliar fungal disease of sugarcane worldwide and is widespread in all sugarcane planting areas in China. Brown stripe is a major disease that seriously affects the output and quality of the sugarcane industry in Yunnan Province, China's second-largest sugar base, while the pathogen of this disease remains not yet fully understood. To address this, we isolated and identified the fungi associated with 68 leaf samples showing typical symptoms of brown stripe from 22 sugarcane varieties in different areas of Yunnan Province. A total of 113 isolates were obtained, which were morphologically similar. Of these, 64 representative isolates were sequenced for the internal transcribed spacer region (ITS), GAPDH and EF-1α loci. All representative isolates grouped with the type strain of Bipolaris setariae in the phylogenetic trees inferred with individual and concatenated sequences of ITS, GAPDH and EF1-α. Pathogenicity test results showed that B. setariae strains were able to induce typical symptoms of brown stripe. The results obtained in this study clarify that only B. setariae is associated with sugarcane brown stripe in Yunnan, China. It is recorded here for the first time as a pathogen causing sugarcane brown stripe in Yunnan, and it is able to infect many major cultivars and new varieties, posing a new threat to the sugar industry in Yunnan Province. In addition, these results provide the scientific basis for the future breeding of disease-resistant varieties and effective prevention and control of sugarcane brown stripe disease.     

基于MaxEnt模型预测梨火疫病菌的潜在地理分布

为探究梨火疫病菌解淀粉欧文氏菌Erwinia amylovora在全球的潜在地理分布,基于其全球分布数据和筛选得到的环境变量,利用MaxEnt模型对其在当前气候和未来气候条件下的潜在地理分布进行预测,并利用刀切法和皮尔逊相关性分析法筛选对梨火疫病菌分布有重要影响的环境变量。结果显示,对梨火疫病菌分布有重要影响的环境变量包括2月平均最高温度、1月平均降水量、7月平均最低温度、温度变化方差、昼夜温差月均值和7月平均降水量,表明春季和夏季的温度和降水对梨火疫病菌的分布有较大影响。在当前气候条件下,梨火疫病菌在全球的适生区分布较广,适生区总面积达到5.58×10⁷ km²,且高适生区主要分布在北美洲沿海地区、地中海沿岸和亚洲中部及东部的部分地区;梨火疫病菌在我国的适生区总面积为7.36×10⁶ km²,占全国陆地总面积的76.70%;在未来气候SSP126和SSP585情景下,梨火疫病菌在全球的适生区总面积分别为5.52×10⁷ km²和5.24×10⁷ km²。表明梨火疫病菌对我国大部分地区有潜在威胁,应加强监测与防控。     

苜蓿地撂荒过程中土壤-微生物-胞外酶及化学计量的变化

紫花苜蓿(Medicago sativa L.)作为优良修复草种在黄土高原广泛种植,然而随着农村人口迁移及土地利用变化,苜蓿人工草地大量弃置的问题已引起广泛关注。为研究苜蓿弃置草地土壤质量变化规律,本研究分析了不同弃置年限(0年、5年和10年)苜蓿草地土壤养分、微生物量、参与土壤碳氮磷(C,N,P)循环的胞外酶活性及其化学计量变化。结果表明：总体上,土壤和微生物C,N含量随弃置年限呈增加趋势,而C,N相关胞外酶活性和化学计量变化幅度较小;土壤和微生物P含量随弃置年限增加而显著降低,但P相关胞外酶活性及化学计量均有不同程度的增加。进一步分析发现：相较于其他土层,表层(0～20 cm)土壤C,N,P含量及其酶活性较高,其变化趋势与总体结果相似;亚表层土壤(20～40 cm)和(80～100 cm)深层土壤C,N,P含量及其酶活性呈先增后减趋势,且各指标较于表层土壤均降低40%～80%。相关分析表明弃置草地土壤由于P匮乏而逐步退化,可通过补施磷肥改善。     

电控喷油器流量性能检测试验装置

设计的电控喷油器性能测试装置,可有效检测喷油器的主要性能指标,为提高发动机燃油动力性、经济性以及降低排放提供了技术支持。检测试验证明,该测试装置具有效率快、精度高、性能稳定的特点,具有实际应用价值。     

巢湖沿岸圩区稻季营养盐的输出特征研究

巢湖流域沿岸分布着很多圩区,人们在圩内进行各种农业活动,圩区营养盐的输出是造成巢湖流域非点源污染的重要因素。为了解圩区农业非点源营养盐的输出特征,笔者通过在巢湖流域河网地区选择比较典型的圩区,于2014年水稻生长期进行了较系统的野外调查观测、取样和室内水质分析,探讨在自然降雨-径流的条件下圩区各类营养盐的浓度变化及输出特征。2014年稻季共进行了9次排水,排水量总计73.09 mm,径流系数为0.37,9次排水事件总氮(TN)和总磷(TP)的平均浓度分别是3.42、0.22 mg/L,圩区水体处于富营养化水平。降雨-径流强度是影响营养盐浓度变化的重要因素,稻季生长期内TN和TP的输出量是0.28、0.017 kg/hm2,占稻季施肥总量的1.7%和0.16%。径流量是影响营养盐输出总量的关键因素,同时施肥量和施肥至排水事件的间隔天数也是是影响营养盐输出的重要因素。     

花生转基因研究进展

同多数豆科作物一样，花生的基因转化技术难度大，且与主要粮食和经济作物相比起步晚，因此进展较慢。本文收集近几年的中外资料，时花生基因转化研究中植抹再生体系的完善过程及存在问题、目前用于转化的目的基因、主要转化方法的改进及转化基因的表达方面的研究进展进行了综述，并指出在花生基因转育中急待解决的问题或需要努力的方向，为进一步进行花生转育研究提供理论基础。     

拟南芥种皮色素形成机制的研究进展

类黄酮为拟南芥种皮的主要成色物质,其生物合成过程受到一系列基因的影响.这些基因中,一部分为结构基因(TT4、TT5、TT6、TT7、FLS1TT3,LDOX和BAN)编码一些酶类参与到类黄酮的生物合成;一部分作为调控基因(TT1,TT2,TT8,TTG1,TTG2和TT16)编码一些酶对生物合成途径起调控作用;另外一些基因(TT12,TT19)编码与色素转运、积累相关的蛋白质。这些基因中的一种或几种发生变异就能影响到类黄酮的生物合成,从而引起拟南芥种皮色泽的变异。在此,就拟南芥种皮的色泽变异及类黄酮生物合成机理作一介绍。