番茄早疫病菌抗啶酰菌胺菌株细胞膜透性变化

为探究番茄早疫病菌Alternaria solani对啶酰菌胺产生抗性后膜透性的变化,采用菌丝生长法、可见分光光度法、电导率法和荧光猝灭法分别测定了抗、感菌株对NaCl渗透压的敏感性、胞内可溶性蛋白和糖的含量、膜渗透率及对啶酰菌胺的吸收量。结果表明:抗性(R-Bos)菌株在2.5 g/L NaCl浓度中生长最快,敏感(S-Bos)菌株则在5 g/L NaCl浓度中生长最快;在0~10 g/L NaCl浓度下,R-Bos菌株的生长明显快于S-Bos菌株,在20~80 g/L NaCl浓度下生长无显著差异;R-Bos菌株的可溶性蛋白和可溶性糖含量显著增高,分别达61.9%~105.2%和133.1%~161.9%;用啶酰菌胺处理菌株后,所有菌株的渗透率上升,膜透性增大,但R-Bos菌株的渗透率始终低于S-Bos菌株;且R-Bos菌株对啶酰菌胺的吸收量明显减少,为48.3%~49.9%。推测番茄早疫病菌对啶酰菌胺产生抗性后,胞内保水能力提高,对渗透压表现出耐受性,同时膜透性降低使得对药剂的吸收能力下降。     

进境货物木质包装检疫风险分级处置研究

本文通过系统识别进境货物木质包装检疫相关风险信息,运用专家打分法和风险矩阵法,研究确定木质包装检疫风险项目评价等级。结合木质包装风险项目和行政相对人行为的危害确定木质包装检疫综合风险等级,并根据不同风险等级提出相应的风险分级处置方案。     

钾对大白菜软腐病发生及保护酶活性的影响

[目的]探究钾肥在抗大白菜软腐病中的作用。[方法]以德高秋丰王和北京新三号为试验材料,通过大田试验,研究3个施钾水平下(0、200、400 kg/hm~2K_2O)德高秋丰王和北京新三号大白菜产量、软腐病发病率及保护酶活性的变化。[结果]施钾量为200 kg/hm~2时显著提高德高秋丰王的产量,而北京新三号产量在施钾量达到400 kg/hm2时显著提高;随施钾量的提高,两品种大白菜软腐病病情指数都呈现降低的趋势,施钾量在400 kg/hm~2时,病情指数最低;两品种的PPO和POD的活性都随施钾量的提高而增强。[结论]施钾对大白菜产量的效应因品种不同而异,增施钾肥可以通过提高保护酶的活性降低大白菜软腐病病情指数。     

Genetic mapping using 1.4M SNP array refined loci for fatty acid composition traits in Chinese Erhualian and Bamaxiang pigs

Chinese indigenous pigs display marked genetic and phenotypic differences compared with western commercial pigs. In this study, we tested the association between 660K SNPs and longissimus muscle fatty acid composition traits in Chinese Erhualian (n = 331) and Bamaxiang (n = 315) pigs based on a customized 1.4 million SNP array. We identified a total of 64 significant associations for 20 fatty acid composition traits at the p‐value threshold of 1 × 10^?6 among which 42 associations in low linkage disequilibrium (r² < .2) with previously reported loci were considered novel. We substantially improved the strength and precision of the associations at four previously detected loci near FADS2, ELOVL7, ELOVL6 and FASN genes, facilitating follow‐up candidate gene studies. Moreover, we also identified loci near ABCD2, ACSBG1, ELOVL5, HPGDS, DAGT2, ACAD10 and ACSL1 genes with function relevant to metabolism of fatty acids. In this study, valuable genetic variants and candidate genes associated with fatty acid composition traits were identified in Erhualian and Bamaxiang pigs. Some identified loci could be used to improve pork nutrition in pig breeding practice. Using the SNP array with higher marker density and less ascertainment bias improved QTL detection power and precision in Chinese indigenous pigs.     

国外林业有害生物防治思想的发展及启示

文中通过回顾国外林业有害生物防治思想的发展历程,指出林业有害生物的防治手段逐渐趋向生态化和综合化,且随着经济社会及技术手段的不断发展,还增加了对防治效果的经济分析,利用实证分析手段,从多维度提升林业有害生物防治效率,实现防治工作中生态效益与经济效益的协调发展;通过介绍美国的科学化防治及德国的生态化防治模式,结合我国现阶段林业有害生物防治思想的发展现状,提出应通过生态化防治理念、科学化防治手段、效率化防治措施及责任化防治意识推动我国林业有害生物防治体系更加健全,从而实现巩固林业建设成果、保障林业经济发展、维护国土生态安全、加快生态文明建设的美好愿景。     

早竹1年生与2年生母竹造林效果比较分析

为了探究不同竹龄早竹母竹对造林效果的影响,实地调查了1年生与2年生母竹造林地的早竹胸径、出笋数量、成竹数量、退笋数量、退笋高度等指标。结果显示:采用2年生母竹造林其出笋数量、成竹数量、退笋数量与新竹胸径均显著高于采用1年生母竹造林,退笋高度两者没有显著差异。研究结果可为早竹造林的母竹年龄选择提供参考依据。     

Molecular characterization of a phytoplasma associated with Euonymus bungeanus witches’ broom in China

Euonymus bungeanus plants exhibiting symptoms of abnormal branches, small leaves and phyllody, which is indicative of E. bungeanus witches’ broom (EbWB) disease, have recently been found in Beijing, China. A phytoplasma from symptomatic E. bungeanus plants was identified by 16S rRNA polymerase chain reaction (PCR) using the phytoplasma‐specific universal primer pair R16mF2/R16mR1. Inoculation of healthy E. bungeanus plants by grafting with diseased scions was also performed. The rp and secY genes of the EbWB phytoplasma were cloned and sequenced as was the 16S rRNA gene. Sequence and phylogenetic analyses of 16S rRNA, rp and secY genes indicated that the phytoplasma associated with E. bungeanus belongs to the 16SrV‐B, rpV‐C and secY‐C subgroup, the same subgroup as the jujube witches’ broom (JWB) phytoplasma that is widely distributed among jujube trees in China. Comparative analyses based on virtual restriction fragment length polymorphism (RFLP) showed that the EbWB phytoplasma is more closely related to another 16SrV‐B subgroup strain: RPWB (Robinia pseudoacacia witches’ broom). To the best of our knowledge, this is the first report of a witches’ broom phytoplasma in E. bungeanus in China, and the findings add a new cultivated plant species to the already broad natural host range of 16SrV‐B subgroup phytoplasmas.     

改革以来农民住房的改善及其原因探讨——基于返乡调查数据的实证分析

不断深入的农村改革和日益强化的支农惠农政策给农民的生产生活带来了巨大的改变。为探究农民住房在改革开放以来发生的变化及其原因,依据全国14个省28个村的返乡调查数据,以2000年为界,从住房面积、类型以及建房目的、资金来源等方面将农民曾住房与现住房进行对比研究。结果表明:农民住房在改革开放至2000年和2000年之后这2个时期在建房主要目的、劳动力使用等方面存在共性,但在住房面积、建房质量、建房目的和资金来源等方面存在明显改进,改善是农民住房变化的"基本面";改善的原因包括宅基地制度改革、农民增收、劳动力转移和惠农政策等。总结改革开放以来改善农民住房的经验,未来应以不断增加农民收入、积极改善农村居住环境与强化住房相关惠农政策为主要侧重点。     

福州地区设施栽培辣椒根腐病病原菌鉴定

为明确福州地区设施辣椒根腐病病原菌种类,于2015-2016年从长乐、福清、闽侯等3地主要设施辣椒栽培区采集辣椒根腐病样本90份,分离到327株病原真菌。根据来源、培养性状以及形态学特征可将这些病原菌分为7种(来源于长乐2种、福清2种、闽侯3种)。通过菌株的致病性测定以及rDNA-ITS序列分析,结果表明来源于长乐的B1、福清的B2和闽侯的B3均具有致病性,并且在系统发育上与茄腐镰孢菌(KT271766.1)同源的置信度达99%。     

土壤肥力和灌水量组合对不同类型小麦光合特性及产量的影响

旨在为小麦节水高产栽培提供理论依据。在池栽条件下,研究了不同土壤肥力和灌水量组合对中筋小麦‘济麦22’和强筋小麦‘济麦20’旗叶净光合速率(Pn)、叶绿素荧光参数及产量构成的影响。2种小麦开花后各生育时期旗叶的光合速率Pn 值、叶绿素荧光参数Fv/Fm 值（PSⅡ最大光化学量子产量）和ФPSⅡ 值（PSⅡ实际光化学量子产量）均随着土壤肥力和灌水量的增加而提高,但土壤肥力因素对上述光合特性指标的影响大于灌水方式因素。随着土壤肥力的提高,Pn 和ФPSⅡ 开始下降的时间逐渐向后延迟,提高土壤肥力有利于减轻环境胁迫对光合的抑制作用。对于2 种小麦的产量和产量构成的影响,土壤肥力和灌水方式之间具有补偿效应。在土壤肥力较高的条件下,2 种小麦限量灌溉和充分灌溉之间产量差异并不显著。培肥地力可以减缓小麦灌水不足导致的光合性能指标的下降,维持生育后期较高的光合产物积累水平。