高温干旱复合胁迫对构树幼苗抗氧化酶活性和活性氧代谢的影响

目的研究马铃薯的耐热机制,为耐热和不耐热的马铃薯品种筛选做参考。方法测量高温胁迫下云南本地3个不同熟期马铃薯品种[云薯 901(早熟)、云薯 305(中晚熟)、合作 88(晚熟)]的表型、部分生理指标和保护酶含量。结果高温胁迫对马铃薯幼苗的生长表型、SOD活性、POD活性和MDA含量都有影响。云薯 901的生长表型优于其他品种;在37 ℃条件下,云薯 901的SOD活性随胁迫时间的延长总体呈下降趋势,而其他品种总体均呈先升高后降低的变化趋势;在30 ℃条件下,云薯 901的POD活性随着胁迫时间的延长总体呈下降趋势,而其他品种总体呈升高的趋势;在23和30 ℃条件下,云薯 901的MDA含量在第5天时明显减少,而其他品种并无该现象。这些结果说明早熟品种云薯 901的耐热表现优于其他熟期较晚的品种。结论持续的高温胁迫影响马铃薯幼苗的生长表型、抗氧化酶活性和膜质,且熟期较晚的品种受到的影响较大,熟期可能是筛选耐热性马铃薯品种的因素之一。     

常见计算机病毒的防范

分析了计算机常见的四种病毒,根据其固有特点提出了相应的防范方法及建议。     

柞蚕新品种永青的选育

柞蚕新品种永青是以“青六号”为基础材料,利用系统选育手段,采用分区饲养、系统分离、定向培育的方法,同时兼顾各项经济指标的综合平衡,通过9年18代的系统选育,育成的具有青黄蚕血统的柞蚕新品种。选育结果：全茧量12.47g,千粒茧重11.99kg,虫蛹统一生命率94.81%;与吉柞88-2、方山黄杂交,增产幅度达15.5%以上。     

Excel应用于方差分析的实训教学探究

针对国内应用型本科湖南文理学院院校概率统计课程的实训教学越来越多地注重Excel作为初学者操作平台的现状,就非平衡数据和嵌套结构的数据在Excel中实现方差分析的过程进行探究。突出以组内矫正数为主线整理数据后简化平方和分解公式的理念,使得Excel中进行方差分析时,数据整理流程完全格式化,平方和的分解步骤更为简洁,自由度分解、F检验等步骤不再繁琐,为非统计专业本科阶段借助Excel电子表格率先实现概率统计课程实训教学的宽口径模式提供借鉴。     

高校大学生国学教育现状及应对策略

在飞速发展的今天,当代大学生尽情享受着现代科技带来的先进成果,却忽视了对传统文化的学习和了解,且各高校开展国学教育的总体情况并不理想,面对这种现状,需要政府、高校和学生一起联动,营造出重视国学教育的社会氛围和校园氛围,尤其各高校要深入改革课程体系、努力创新教学计划,以期达到深入开展国学教育、提升大学生人文素养的目的。     

Effect of hay type on cecal and fecal microbiome and fermentation parameters in horses

The effect of hay type on the microbiome of the equine gastrointestinal tract is relatively unexplored. Our objective was to characterize the cecal and fecal microbiome of mature horses consuming alfalfa or Smooth Bromegrass (brome) hay. Six cecally cannulated horses were used in a split-plot design run as a crossover in two periods. The whole plot treatment was ad libitum access to brome or alfalfa hay fed over two 21-d acclimation periods with subplots of sampling location (cecum and rectum) and sampling hour. Each acclimation period was followed by a 24-h collection period where cecal and fecal samples were collected every 3 h for analysis of pH and volatile fatty acids (VFA). Fecal and cecal samples were pooled and sent to a commercial lab (MR DNA, Shallowater, TX) for the amplification of the V4 region of the 16S rRNA gene and sequenced using Illumina HiSeq. The main effects of hay on VFA, pH, and taxonomic abundances were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of hay, hour, location, period, and all possible interactions and random effect of horse. Alpha and beta diversities were analyzed using the R Dame package. Horses fed alfalfa had greater fecal than cecal pH (P ≤ 0.05), whereas horses fed brome had greater cecal than fecal pH (P ≤ 0.05). Regardless of hay type, total VFA concentrations were greater (P ≤ 0.05) in the cecum than in feces, and alfalfa resulted in greater (P ≤ 0.05) VFA concentrations than brome in both sampling locations. Alpha diversity was greater (P ≤ 0.05) in fecal compared with cecal samples. Microbial community structure within each sampling location and hay type differed from one another (P ≤ 0.05). Bacteroidetes were greater (P ≤ 0.05) in the cecum compared with the rectum, regardless of hay type. Firmicutes and Firmicutes:Bacteroidetes were greater (P ≤ 0.05) in the feces compared with cecal samples of alfalfa-fed horses. In all, fermentation parameters and bacterial abundances were impacted by hay type and sampling location in the hindgut.     

鸭IFIT5基因(544G>A)多态性与部分免疫指标的关联分析

探索IFIT5基因作为抗性性状的候选标记的可能性,为家禽抗病育种提供一些参考依据。以樱桃谷北京鸭、苏牧麻鸭(樱桃谷鸭×金定鸭)、金定鸭、白羽番鸭为试验材料,利用DNA直接测序技术扫描IFIT5基因单核苷酸多态性(SNP),并分析其与部分免疫指标的关联性。结果表明:仅在IFIT5基因外显子2上检测到一个错义突变(G544A),产生2种等位基因,2种基因型(GG、GA),未发现有AA基因型。经χ2检验,4个鸭群体只有金定鸭和苏牧麻鸭处于Hardy-Weinberg平衡状态。关联分析结果显示:樱桃谷鸭体内H5含量GG型显著高于GA型(P0.05),而Ig M含量GG型显著低于GA型(P0.05),其余免疫指标均无显著差异(P0.05);苏牧麻鸭体内H5含量GG型极显著高于GA型(P0.01),其余免疫指标均无显著差异(P0.05);金定鸭不同基因型各免疫指标均无显著差异(P0.05)。白羽番鸭在+544位点均为GG纯合基因型。由此可以看出,IFIT5(544GA)可作为樱桃谷鸭体内H5含量的候选分子标记。     

稻粉虱的发生及其化学防治药剂筛选

稻粉虱Aleurocybotus indicus David et Subramaniam, 属半翅目粉虱科, 以刺吸式口器为害水稻叶片而导致产量损失, 是我国闽?赣?浙等稻区的一种偶发性水稻害虫, 近20多年已鲜有报道, 但2019年-2021年在中国水稻研究所富阳试验农场稻田暴发?本文描述了稻粉虱的为害症状和形态特征, 并配以原色照片; 克隆得到了稻粉虱线粒体DNA COⅠ基因片段, 发现其与烟粉虱Bemisia tabaci序列一致性最高(85.80%); 田间调查表明, 富阳试验农场及周边稻田稻粉虱均有不同程度的发生, 但前者发生量明显较高(每个分蘖最高可达251头), 推测可能与农场温室内的稻粉虱越冬虫源有关; 利用稻苗浸渍法评估了不同作用机制的7种杀虫剂对稻粉虱的毒力, 发现双丙环虫酯?氯虫苯甲酰胺?氟啶虫胺腈?氟啶虫酰胺和溴氰虫酰胺对稻粉虱成虫均有较好的杀虫活性, 其中前4种药剂推荐中剂量处理后72 h的校正死亡率均可达100%, 其LC50分别为3.028?3.769?6.405 mg/L和7.894 mg/L?本研究可为我国稻粉虱的识别诊断和化学防治提供重要依据?     

A New Monte Carlo Method Based on State Analysis

A new Monte Carlo Method for system reliability evaluation is proposed in this paper. The repeated sampling of system states with relatively great probabilities is avoided in the simulation,thus the sampling efficiency is significantly improved. Besides,the negative correlations used in different trials can further reduce the estimated varinaces. The sparse matrix technique is employed to reduce the memory requirement and to save the computer time. Comparative studies show that the method proposed is of great value and the application to the IEEE reliability test system (power system) is successful.