呼伦贝尔黄花苜蓿与紫花苜蓿杂交及优异单株选育研究

利用常规杂交育种技术,将国内高产、抗寒品种龙牧801苜蓿(Medicago sativa cv.Longmu No.801)和国外具有多叶性状品种驯鹿苜蓿(M.sativacv.AC Caribou)与呼伦贝尔黄花苜蓿(Medicago falcata cv.Hulunbeier)分别进行正反杂交,统计杂交结荚数、结荚率、每荚种子数,并观测F1代单株性状。结果表明:父母本和正反交对杂交结荚数、结荚率和每荚种子数存在显著影响(P0.05),其中,呼伦贝尔黄花苜蓿(♀)×引进品种驯鹿苜蓿(♂)的结荚数、结荚率显著高于其他杂交组合,且各组合正交显著高于反交。从F1代杂交株中筛选出84个优异单株和5株具有多叶性状的优异单株,其株高、茎叶比、分枝数和单株干重均显著高于对照亲本,可以作为育种材料进行进一步的选育。     

西藏草原5种主要有毒植物营养成分

采用国家标准法对西藏天然草原茎直黄芪(Astragalus strictus)、甘肃棘豆(Oxytropis kansuensis)、毛瓣棘豆(Oxytropis sericopetala)、瑞香狼毒(Stellera chamaejasme)和藏橐吾(Ligularia rumicifolia)5种主要有毒植物不同物候期常规营养成分和矿质元素含量进行测定。结果显示,在5种植物中,粗蛋白平均含量以茎直黄芪最高,其次为甘肃棘豆,且两者粗蛋白含量均超过19%;茎直黄芪中花期粗蛋白含量最高,花前期最低,花期和花果期差异不显著(P0.05);而甘肃棘豆中粗蛋白含量以花前期最高,花果期最低,花前期和花期差异不显著。粗纤维平均含量由高到低依次为毛瓣棘豆、藏橐吾、茎直黄芪、甘肃棘豆和瑞香狼毒,且均以花果期最高,花前期最低。5种植物Mg、Fe、Cu、Mn和Zn含量均以花前期最高,花期次之,花果期最低;但Se含量花果期相对较高。由此得出,茎直黄芪和甘肃棘豆营养较为丰富,具有潜在饲用价值,毛瓣棘豆、瑞香狼毒和藏橐吾营养价值偏低。     

甘肃陇南地震扰动区植被群落特征

地震扰动对当地生态环境造成极大的破坏,引起植被群落种类组成、群落结构的变化,本研究采用样带结合海拔梯度的方法,于2013年8-9月,调查和研究了甘肃陇南武都区清水沟植被群落的种类组成、群落结构受地震扰动后的现状。结果表明,研究区内共发现34种植物,分属16科30属,主要以禾本科和菊科植物为主,群落垂直结构明显,大体分为3层;植物群落中多年生草本植物种类最多,是优势生活型,其次是灌木、藤本,无乔木分布;Shannon-Wiener多样性指数(H')和Pielou均匀度指数(E)表现为中坡位下坡位上坡位,Simpson优势度指数(D)表现为上坡位下坡位中坡位。     

Genetic and non-genetic factors influencing KLH binding natural antibodies and specific antibody response to Newcastle disease in Kenyan chicken populations

This study aimed at investigating the influence of genetic and non-genetic factors on immune traits to inform on possibilities of genetic improvement of disease resistance traits in local chicken of Kenya. Immune traits such as natural and specific antibodies are considered suitable indicators of an individual's health status and consequently, used as indicator traits of disease resistance. In this study, natural antibodies binding to Keyhole Limpet Hemocyanin (KLH-NAbs) was used to measure general disease resistance. Specific antibodies binding to Newcastle disease virus (NDV-IgG) post vaccination was used to measure specific disease resistance. Titers of KLH-NAbs isotypes (KLH-IgM, KLH-IgG and KLH-IgA) and NDV-IgG were measured in 1,540 chickens of different ages ranging from 12 to 56 weeks. A general linear model was fitted to determine the effect of sex, generation, population type, phylogenetic cluster, line, genotype and age on the antibody traits. A multivariate animal mixed model was fitted to estimate heritability and genetic correlations among the antibody traits. The model constituted of non-genetic factors found to have a significant influence on the antibody traits as fixed effects, and animal and residual effects as random variables. Overall mean (±SE) concentration levels for KLH-IgM, KLH-IgG, KLH-IgA and NDV-IgG were 10.33 ± 0.04, 9.08 ± 0.02, 6.00 ± 0.02 and 10.12 ± 0.03, respectively. Sex, generation and age (linear covariate) significantly (p < 0.05) influenced variation across all the antibody traits. Genotype effects (p < 0.05) were present in all antibody traits, apart from KLH-IgA. Interaction between generation and line was significant (p < 0.05) in KLH-IgM and NDV-IgG while nesting phylogenetic cluster within population significantly (p < 0.05) influenced all antibody traits, apart from KLH-IgA. Heritability estimates for KLH-IgM, KLH-IgG, KLH-IgA and NDV-IgG were 0.28 ± 0.08, 0.14 ± 0.06, 0.07 ± 0.04 and 0.31 ± 0.06, respectively. There were positive genetic correlations (0.40–0.61) among the KLH-NAbs while negative genetic correlations (−0.26 to −0.98) were observed between the KLH-NAbs and NDV-IgG. Results from this study indicate that non-genetic effects due to biological and environmental factors influence natural and specific antibodies and should be accounted for to reduce bias and improve accuracy when evaluating the traits. Subsequently, the moderate heritability estimates in KLH-IgM and NDV-IgG suggest selection possibilities for genetic improvement of general and specific immunity, respectively, and consequently disease resistance. However, the negative correlations between KLH-NAbs and NDV-IgG indicate the need to consider a suitable approach that can optimally combine both traits in a multiple trait selection strategies.     

Anethole inhibits growth of recently emerged multidrug resistant toxigenic Vibrio cholerae O1 El Tor variant strains in vitro

To search natural compounds having inhibitory effect on bacterial growth is important, particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens. Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent of diarrheal disease cholera, is becoming a great concern. As an approach of searching new antimicrobial agents, here, we show that anethole, a well-studied natural component of sweet fennel and star anise seeds, could potentially inhibit the growth of MDR O1 El Tor biotype, the ongoing 7th cholera pandemic variant strains of toxigenic V. cholerae. The minimum inhibitory concentration (MIC) of anethole against diverse O1 El Tor biotype strains is evaluated as 200 µg/ml. Moreover, the effect of anethole is bactericidal and exerts rapid-killing action on V. cholerae cells. This study is the first report which demonstrates that anethole, purified from natural compound, is a potent inhibitor of growth of toxigenic V. cholerae. Our data suggest that anethole could be a potential antimicrobial drug candidate, particularly against MDR V. cholerae mediated infections.     

生态景观林带在城乡宜居建设中的作用

面对伴随着城市现代化进程所带来的环境问题,宜居城乡建设是改善居住环境问题的重要举措;生态景观林带是以改善破碎化的森林斑块和绿化带、以增强森林为主体的自然生态空间的连通性、以观赏性为目的和以点、线、面相结合的景观廊道网络。生态景观林带在城乡宜居建设中发挥着改善自然环境与人文环境的双重作用,促进了城市与乡村的耦合,是城乡宜居建设的有效途径。     

福建柏自然资源调查研究及建议

调查了福建省内外的福建柏自然资源,分析了福建柏自然资源的分布情况及其现状,并针对保护工作提出了一些对策及建议。     

小花蝽在不同植物上的种群密度

2010―2016年通过人工栽培小区试验，系统调查了33科152种植物上小花蝽复合种群发生动态。多年调查结果表明：除黄柴胡外，其余151种植物上均有小花蝽发生，但小花蝽的种群密度在不同调查年度的植物种类上差异较大。小花蝽种群发生密度最高的植物是蓝蓟，其次是芥菜、硫华菊、荞麦、紫花苜蓿、红麻、陆地棉等有大量蚜虫及开花周期较长的植物。本研究明确了农田生境中小花蝽发生密度较高的候选功能植物，为下一步利用植物多样性促进农田小花蝽种群的保育及控害功能提供科学依据。     

草地贪夜蛾的天敌昆虫资源、应用现状及存在的问题与建议

草地贪夜蛾Spodoptera frugiperda（J.E.Smith）是原产于美洲热带和亚热带地区的重大农业害虫，具有迁飞快、寄主广、繁殖强、为害重、适生力强等特点。自2019年初入侵我国以来，现已蔓延到我国21个省（市、自治区），草地贪夜蛾将在我国定殖并呈现周年常态化发生态势，对我国玉米产业的发展构成严重威胁。本文综述了草地贪夜蛾的国内外寄生性和捕食性天敌昆虫及其应用情况，并就我国天敌昆虫产业发展的现状和存在的问题提出了建议，以期为应用天敌昆虫防控草地贪夜蛾提供参考。     

益蝽对草地贪夜蛾高龄幼虫的捕食能力评价和捕食行为观察

为了探究天敌昆虫益蝽对草地贪夜蛾的捕食潜力，本试验在室内条件下评价了益蝽5龄若虫对草地贪夜蛾6龄幼虫的捕食能力，结合田间观察总结了益蝽的捕食行为特点。结果表明：益蝽5龄若虫对草地贪夜蛾6龄幼虫的捕食功能反应符合HollingⅡ模型，对草地贪夜蛾6龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为4.671头、1.512和0.215 d；益蝽偏食活猎物，对草地贪夜蛾幼虫致死量大，当草地贪夜蛾幼虫密度大时，益蝽将一头猎物刺吸致死后并不持续吸取，而是快速攻击其他猎物，这一特点对于控制草地贪夜蛾种群数量十分有利。