苹果细胞分裂素氧化酶基因MdCKX7.2的克隆及抗性鉴定

采用同源克隆和PCR技术从‘嘎拉’苹果(Malus×domestica Borkh.)中克隆细胞分裂素氧化酶基因MdCKX7.2(基因序列号:MDP0000279125)。该基因含有1 542 bp的完整开放阅读框,编码513个氨基酸。利用Plant CARE数据库对MdCKX7.2启动子顺式作用元件进行预测分析,发现MdCKX7.2启动子序列中存在光、干旱、脱落酸、水杨酸、茉莉酸甲酯等响应元件。基因表达分析发现,‘嘎拉’幼苗中MdCKX7.2的表达明显受干旱和ABA的诱导。通过农杆菌介导的遗传转化获得MdCKX7.2转基因拟南芥植株。抗性试验表明,异位表达MdCKX7.2基因明显提高了拟南芥对干旱胁迫的抗性。拟南芥种子萌发试验表明,在拟南芥中异位表达MdCKX7.2提高了植株对ABA的敏感性,种子萌发率和幼苗鲜质量明显下降,与种子萌发相关基因的表达量明显上调。以上试验结果表明,MdCKX7.2在植物非生物胁迫响应中发挥重要作用。     

白银市土地利用变化对生态系统服务价值的影响

为了明确白银市土地利用状况与生态系统服务价值之间的关系,进一步确定白银市各土地利用类型对生态系统的影响程度。本研究选择当量因子法评价白银市2009—2017年土地利用状况、生态系统服务价值以及两者之间的关系。结果表明:（1）2009—2017年,白银市生态系统服务价值总量从56.75亿元下降到56.49亿元,总体呈下降趋势,各项生态系统功能和生态系统服务都呈下降趋势;草地生态系统服务价值减少了2549.18万元,减少最多,人口对生态系统负荷呈减轻趋势;（2）白银市土地利用类型对生态系统服务价值具有较大的影响,主要受建设用地增加较多,草地和林地面积减少影响较大,在以后的发展中,要从保护生态用地、挖掘存量建设用地方面,探索出一条生态优先、绿色发展的新路子。     

Experimental infection of Mytilus edulis by two Vibrio splendidus-related strains: Determination of pathogenicity level of strains and influence of the origin and annual cycle of mussels on their sensitivity

This study aimed at assessing the pathogenicity of two Vibrio splendidus-related species and evaluating the influence of the origin and annual life cycle of mussels on their sensitivity during a bacterial challenge. Thus, in vivo infection assays were made with Vibrio crassostreae 7T4_12 and Vibrio splendidus 3G1_6, over, respectively, thirteen and 9 months, on adult blue mussels from five recruitment areas in France. Two bacterial concentrations were tested: one consistent with the loads of Vibrio spp. in environment and mussel tissues (~10⁵ CFU/ml) and another one much higher (~10⁸ CFU/ml). The tested environmental concentration has no pathogenic effect whatever the time of year, the strain used and the origin of mussels. However, at the highest concentration, a pathogenic effect was observed only at specific moments, and one of the origins appeared to be more resistant. The physiological state of mussels—depending on the time of year—seemed significant in mussels’ sensitivity, as their recruitment origin. This study is the first to test the pathogenicity of V. splendidus-related strains at concentrations close to what is found in the wild, over the annual cycle of mussels, and considering their origin.     

Metabolic rates from Bluntnose minnow (Pimephales notatus) populations at lower latitudes are more sensitive to changes in temperature than populations at higher latitudes

Predicting the potential effects of changes in climate on freshwater species requires an understanding of the relationships between physiological traits and environmental conditions among populations. While water temperature is a primary factor regulating metabolic rates in freshwater ectotherms, how metabolic rates vary across the species range is unclear. In addition, photoperiod has also been hypothesised to influence metabolic rates in freshwater taxa based on seasonal changes in activity rates. Using an experimental approach, we investigated whether variation in routine metabolic rate (RMR) and sensitivity of RMR to changes in temperature are correlated with local thermal regimes, photoperiods and body mass among ten populations across the geographic range of the Bluntnose minnow (Pimephales notatus), a North American freshwater fish species. Routine metabolic rate data were collected from populations acclimatised to three temperature treatments (9, 18 and 27°C) and correlated with water temperature and photoperiod estimates at collection locations for each population. Routine metabolic rate was negatively correlated with minimum photoperiod at 9°C, negatively correlated with weekly high temperature at 18°C and positively correlated with weekly high temperature at 27°C. Body mass was also a predictor of RMR at each temperature treatment. Thermal sensitivity of RMR was positively correlated with weekly high temperature, indicating that individuals from warmer low latitude populations experienced greater sensitivity of RMR to changes in temperature than individuals from cooler high latitude populations. These results indicate differential responses among populations to variation in temperature and suggest the importance of recognising this variation when characterising responses of freshwater taxa to increases in water temperature.     

基于公共天气预报的三江平原ET0预报模型比较及敏感性分析

为了提出适合我国三江平原的高精度ET0预报方法,基于该区6个气象站点的天气预报数据和实测气象数据,以FAO56-Penman-Monteith(FAO56-PM)公式计算值为基准,比较Hargreaves-Samani(HS)、Thornthwaite(TH)和Blaney-Criddle(BC)3个ET₀预报模型的效果,对最优模型进行敏感性分析。结果表明:3个模型1~7 d预见期平均绝对误差均值分别为0.66、0.65、0.65 mm/d,均方根误差分别为0.93、0.96、0.95 mm/d,相关系数分别为0.857、0.828、0.840。1~5 d预见期最优预报模型为HS模型,6~7 d为TH模型。总体上预报精度由高到低为HS、TH、BC模型,建议采用HS模型在三江平原开展ET₀预报,HS模型预报对最高温预报的敏感性大于最低温。其预报值在夏季受温度预报误差影响最大,冬季最小,4季整体误差较小。研究可为灌溉预报提供较准确的数据基础。     

苹果轮纹病菌对吡唑醚菌酯的敏感性及Cytb基因序列分析

为了明确苹果轮纹病菌Botryosphaeria dothidea对吡唑醚菌酯的敏感性和吡唑醚菌酯的靶标基因序列, 采用菌丝生长速率法测定了水杨肟酸对B. dothidea 菌丝生长的作用, 探讨了添加或不添加水杨肟酸的情况下病原菌对吡唑醚菌酯敏感性的变化; 并测定了不同产区的80株B. dothidea 对吡唑醚菌酯的敏感性以及440株B. dothidea 对吡唑醚菌酯的抗性; 然后, 扩增并分析了具有不同敏感性的菌株的细胞色素b基因 (Cytb) 序列?结果表明:不同浓度水杨肟酸对菌丝生长的抑制作用不同?添加40 μg/mL水杨肟酸不影响吡唑醚菌酯的EC50?菌株的敏感性频率符合近似正态分布, 各产区菌株对吡唑醚菌酯的敏感性没有显著差异, 吡唑醚菌酯平均EC50为(2.95±2.11) μg/mL, 没有检测到抗性菌株?靶标基因序列分析表明, Cytb基因在F129?G137和G143位密码子上没有产生点突变, 首次发现在143位密码子后有内含子插入?     

日本乙型脑炎病毒ELISA抗体检测试剂盒的研制及初步应用

采用日本乙型脑炎病毒单克隆抗体预包被酶标板,将纯化的日本乙型脑炎病毒(JEV)作为检测用抗原,利用包被捕获法建立了用于检测猪乙型脑炎抗体的间接ELISA法。采用建立的ELISA法对50份已知阴性血清样本检测,临界OD450nm值为0.343,ELISA与IFA对200份血清进行平行检测,总符合率为92.9%,与商品化的同类国产试剂盒的符合率为95%。与其他常见的猪病毒阳性血清抗体无交叉反应,2~8℃保存12个月稳定。研制的ELISA抗体检测试剂盒为临床JEV血清抗体检测及其疫苗的免疫效果评价提供了技术手段。     

Study on Biological Characteristics and Drug Sensitivity of Haemophilus parasuis Isolated in Sichuan Province

The study was aimed to investigate the biological characsteristics and drug sensitive tests of Haemophilus parasuis isolated in Sichuan province.This paper reported the biological characteristics,16S rRNA gene PCR and drug sensitive test of the isolates by technique of microbiological and molecular biology.The results showed that the isolates had micro anaerobic and could produce satellite phenomenon,the isolates were just same in biochemical characteristics with field isolates in other area.All the isolates amplified 821 bp 16S rRNA gene.And drug sensitive tests showed that the isolates were highly sensitive to cefradine,ampicillin,cefradine,amoxicillin,cefaclor,ofloxacin,cefotaxime and furadantin,the sensitive rate was 75.61% to 87.80%,but the isolates were high resistance to lincomycin,carbenicillin,enrofloxacin,amikacin and sulfamethoxazole,and multiple-drug resistance was found among the isolates,the number of bacterial strains resistant to antibiotics were more between five and eight,the resisitance strains were 21.95% to 30.49%,7 isolates were even resistant to 13 antibiotics.The results showed the phenomenon of drug resistance of the isolates was very serious.     

牡丹峰国家森林公园开发强度控制策略

通过构建景观敏感度和景观阀值评价体系,对牡丹峰国家森林公园各景区的景观敏感度和景观阀值进行评价;根据评价得到的各个景区的敏感度和阀值级别,分别制定了各个景区相应的开发利用策略。     

An analysis of a silvopastoral system for the marginal land in the Southeast United States

Almost 20 million acres of non-forest cropland in the South can be classified as marginal. Demand projections for forest products call for a 40 percent increase by year 2030. Recent regenerated tree acres lag behind harvested acres. Multiple land use practices combining trees and grazing adjust cash flows forward mitigating negative flow period associated with conventional forest production. Profit opportunities for private, non-industrial landowners can be increased by ranking inputs in order of changes to net present value(NPV). A sensitivity analysis of an agroforestry scenario, including trees, beef cattle, and pasture, allows producers to concentrate management efforts where returns are greatest. Model results show greatest returns to NPV was realized from improvement to Chip-N-Saw income. The least increase in NPV came when the cost of control burns was changed.