甜菜BvGSTU9基因的生物信息学及在镉胁迫下的表达分析

为了进一步研究甜菜谷胱甘肽转移酶BvGSTU9 (LOC104894060)在重金属胁迫过程中的功能。本研究以‘780016B/12优’为实验材料,对该基因序列特征、结构、功能进行预测分析,并利用qPCR检测该基因在不同浓度镉胁迫下的表达量变化。结果显示甜菜BvGSTU9基因全长925 bp,开放阅读框675 bp,编码了由224个氨基酸组成的不稳定膜外蛋白。BvGSTU9与菠菜、藜麦的氨基酸序列相似性较高,与系统发育进化树分析结果基本相符。二级和三级结构预测表明该基因主要由α-螺旋、β-折叠、延伸链及无规则卷曲组成。qPCR显示BvGSTU9基因在不同浓度的镉胁迫下均受到不同程度的诱导,因此可以推断甜菜BvGSTU9基因无论从结构还是功能上,与镉逆境胁迫存在着一定的应答关系。研究结果也为甜菜耐重金属镉机制研究提供参考依据。     

水杨酸对桃树花期抗寒性的影响

在华北和东北地区桃树花期低温(0℃左右)引起坐果率严重下降的现象时有发生。以管理手段延迟花期成本较高。水杨酸(SA)能诱导抗氰呼吸，有产热效应。本试验对施用外源SA降低桃树花期低温伤害的效应进行了研究，期望为桃树花期提供低成本的抗寒手段。     

关中驴对6株动物病毒抗原的免疫应答试验

以关中驴为试验动物 ,用猪瘟病毒(HCV )、犬细小病毒 (CPV )、兔瘟病毒(RHDV)、鸡新城疫病毒 (NDV)、伪狂犬病毒(PRV)等病毒进行免疫 ,检测所产生的抗体效价 ,并与猪、鸡、兔、犬、及猫等动物进行比较。试验结果表明 ,关中驴与对照动物产生的抗体效价一致 ,证明了关中驴可替代其它动物用于生物制品研究     

遗传同型交配下母子间基因型联合分布的信息熵性质

定义了遗传同型交配下一对等位基因群体的基因库信息熵和基因型信息熵，给出并讨论了世代交替中母子间基因型联合分布及其信息熵性质。并从信息角度加以解释；最后，应用Matlab软件进行数据模拟，验证了所得结论的正确性。     

Releases in israel ofAphelinus perpallidus,a recently introduced parasite of the pecan blackmargined aphid,Monellia caryella

Six shipments totaling 3452 mummies of the blackmargined aphid,Monellia caryella (Fitch), parasitized withAphelinus perpallidus Gahan, were obtained by air freight during the years 1982-1985 from Texas A&M Research Center, El Paso, Texas. About two-thirds of the mummies did not yield parasites. A colony ofA. perpallidus was established in the laboratory. Under laboratory conditions the percentage of emerged parasites was higher than that in the imported mummies, and the parasite had very limited impact on the aphid population. Field releases of the parasite were made but no establishment ofA. perpallidus was observed through the years.     

Gene Flow Analysis of Phytophthora porri Reveals a New Species: Phytophthora brassicae Sp. Nov.

Isozyme analysis and sequence analysis of the internal transcribed spacer regions (ITS-1 and ITS-2) and the 5.8S subunit of the ribosomal DNA gene repeat were used to examine whether isolates of Phytophthora porri from Allium and Brassica represent a single homogeneous species. Twenty-six strains of P. porri, 16 strains isolated from the genus Allium, and 10 strains isolated from the genus Brassica, were analyzed using malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and lactate dehydrogenase (LDH), represented altogether by four putative loci (Mdh-2, Idh-1, Idh-2, and Ldh-2). Isozyme analysis revealed that strains isolated from Allium contained five private alleles at three isozyme loci (Ldh-2 ⁸³, Ldh-2 ¹⁰⁴, Idh-1 ¹⁰⁸, Idh-1 ¹¹², and Idh-2 ⁹⁸), whereas six different alleles were observed at four isozyme loci (Ldh-2 ⁸⁵, Ldh-2 ¹⁰⁰, Ldh-2 ¹¹⁴, Idh-1 ¹⁰⁰, Idh-2 ¹⁰⁰, and Mdh-2 ¹¹¹) in strains obtained from Brassica. The heterozygosity at the Ldh-2 locus, differing in allele composition, however, between strains from Allium and Brassica, was present in all strains, indicating that it is probably fixed. Sequence analysis of the ITS regions and the 5.8S subunit showed consistent differences between isolates from Allium and isolates from Brassica. Based on isozyme data, ITS sequence analysis and formerly published differences in restriction enzyme patterns of mitochondrial DNA, morphology and pathogenicity, it was concluded that the isolates of P. porri Foister did not represent a homogeneous species. Isolates from Brassica constitute a distinct species which is described here as P. brassicae sp. nov. It was inferred from isozyme patterns, which were in no case intermediate between the two species, that P. porri and P. brassicae do not hybridize and are reproductively isolated by barriers to gene flow.     

Using the indicator amino acid oxidation technique to study threonine requirements in horses receiving a predominantly forage diet

Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. To evaluate amino acid metabolism and requirements, the indicator amino acid oxidation (IAAO) method has been successfully used in other species. The objective of this research was to estimate threonine requirements in mature horses fed timothy hay and concentrate in 4:1 ratio using the IAAO method. Six Thoroughbred mares (579.9 ± 46.7 kg) received each of 6 levels of threonine intake, 41, 51, 61, 70, 80 and 89 mg/kg BW/day, in a randomly determined order. Each study period was 7‐day long, and on day 6, blood samples were collected before and 90 min after feeding to measure amino acid concentrations using HPLC. On day 7, horses underwent IAAO procedures, which included a 2‐hr primed, constant intravenous infusion of [¹³C]sodium bicarbonate to measure total CO₂ production and a 4‐hr primed, constant oral administration of [1‐¹³C]phenylalanine to estimate phenylalanine oxidation to CO₂. Blood and breath samples were collected to measure blood [¹³C]phenylalanine, using GC‐MS analysis and breath ¹³CO₂ enrichment, using an infrared isotope analyser. Increasing threonine intake levels did not affect plasma phenylalanine oxidation by the ANOVA test (p > 0.05) but resulted in a linear decrease in phenylalanine oxidation (p = 0.04) without a breakpoint by the orthogonal linear contrast. This study is the first attempt to evaluate threonine requirements in horses by the IAAO method; however, threonine requirements are still unknown in mature horses at this time.     

重庆市部分地区H5和H7重组禽流感病毒二价灭活苗免疫效果监测

2017年7月7日,农业部决定对全国家禽开展H7亚型流感免疫。为了掌握重组禽流感病毒(H5+H7)二价灭活苗的免疫效果,2017年8—9月,重庆市动物疫病预防控制中心进行了控制性试验和大面积临床监测。控制试验结果表明:首免15 d后,H7亚型禽流感抗体合格率可达70.00%,H5亚型抗体合格率仅为10.00%;首免22 d后,H7亚型禽流感抗体合格率达到93.33%,H5亚型抗体合格率达到60.00%;该疫苗未出现严重免疫副反应;H7亚型禽流感抗体产生的时间早于H5亚型。随机选取5个区县,采集414份免疫血清进行监测。结果显示:二价灭活苗免疫21 d后,H5和H7亚型禽流感抗体平均合格率分别为92.27%和76.00%;5个区县的抗体水平存在差异;蛋鸡抗体水平高于肉鸡。控制试验及临床监测结果提示,该疫苗免疫效果确实,但部分区县仍存在免疫抗体水平不高的养禽场。因此,在新旧疫苗交替使用期间,各地应高度重视高致病性H5和H7亚型禽流感防治工作,尤其是肉鸡。     

DMDC前处理对巨峰冰葡萄酒发酵及其品质的影响

【目的】研究二甲基二碳酸盐(DMDC)杀菌技术对巨峰冰葡萄酒发酵过程及品质的影响,为DMDC应用于巨峰冰葡萄酒发酵加工提供理论依据。【方法】在糖质量浓度分别为350和400 g/L的浓缩葡萄浆醪中,分别添加250 mg/L DMDC和200 mg/L亚硫酸盐进行杀菌处理,比较2种杀菌处理方法对巨峰冰葡萄酒发酵期间可溶性固形物、总糖、还原糖、酒精度、pH、总酸、挥发酸、花色苷等理化指标及酒体感官评分的影响。【结果】处理前,当糖质量浓度分别为350和400 g/L时,其对葡萄醪的微生物菌落总数无显著影响。与处理前相比,DMDC处理能降低葡萄醪的菌落总数、霉菌和乳酸菌菌落数,优于亚硫酸盐处理;DMDC处理使葡萄醪的酵母菌菌落数降低至检测限之下,而亚硫酸盐对酵母菌只有微弱的杀菌作用。当糖质量浓度为400 g/L时,DMDC处理的可溶性固形物、总糖、还原糖质量浓度均高于亚硫酸盐处理,且二者之间差异显著;当糖质量浓度为350 g/L时,DMDC与亚硫酸盐处理之间的可溶性固形物、总糖、还原糖质量浓度无差异显著。在整个发酵过程中,当糖质量浓度分别为350和400 g/L时,DMDC处理的酒精度、pH均高于亚硫酸盐处理,DMDC处理的花色苷质量浓度低于亚硫酸盐处理,但二者总酸质量浓度差异不大。在发酵前期,各处理组的挥发酸质量浓度无显著差异(P0.05);在发酵后期,当糖质量浓度为400 g/L时,DMDC和亚硫酸盐处理的挥发酸质量浓度均较高。由感官评价结果可知,DMDC处理能改善巨峰冰葡萄酒的口感,酒体颜色呈桃红色;亚硫酸盐处理巨峰冰葡萄酒的口感较差,酒体颜色呈紫红的宝石色。【结论】用250 mg/L DMDC对葡萄浆醪进行处理可能成为一种有效控制发酵冰葡萄酒品质的杀菌前处理方式。     

论稳定脱贫与乡村振兴的有机衔接

新时代背景下的稳定脱贫和乡村振兴,具有目标的统一性和措施的互补性,实现二者有机衔接意义重大。本文基于贫困治理的历程与特征梳理,结合苏北地区的实地调研,分析稳定脱贫与乡村振兴有机衔接理论上的逻辑基础与实践上的认知偏差,探讨促进稳定脱贫与乡村振兴有机衔接的政策着力点。研究表明,改革开放以来,我国贫困治理依据瞄准对象经历了救济式扶贫、开发式扶贫、产业扶贫和精准扶贫四个阶段,显示出贫困治理方式从"输血式救济"到"造血式开发"转变、扶贫瞄准对象遵循"区域—县—村—户"的顺次由"面"及"点"演变、贫困治理目标由"解决温饱"到"两不愁,三保障"的"民生改善"转变三个特征。当前,稳定脱贫与乡村振兴相衔接应该遵循以乡村产业为接口,以乡土农民为主体,以乡村创业为手段的内在逻辑。苏北地区在脱贫攻坚与乡村振兴有机结合做了大量的工作,并探索出一些积极做法。但是,稳定脱贫与乡村振兴有机衔接的实践仍然存在一些认知偏差,表现为以传统工业化思维发展乡村产业,忽视彰显乡村特色;以传统城市化思维实现农民市民化,忽视农民主体地位;以传统城乡二元思维解决农民就业问题,忽视农民创业能力。因此,需要以农业为基础衍生新业态,以农民为主体提升新能力,以创业为手段积蓄新动能,才能实现稳定脱贫与乡村振兴,推动农村经济持续发展。