水稻对褐飞虱的抗性与挥发性次生物质总量的关系

运用水蒸气蒸馏法提取水稻植株的挥发性次生物质,并进行GC/MS分析,比较水稻抗、感褐飞虱植株中挥发性次生物质总量的差异.结果表明,感性植株的挥发性次生物质总量明显高于抗性植株,前者比后者高45.4%;挥发性次生物质总量随植株抗性增强而降低,1级最低,7级最高;挥发性次生物质总量随植株所含抗性基因数的增加而减少.     

33株临床分离菌的药敏试验分析

收集标准菌株2株和临床分离菌株共33株,采用NCCLS推荐的微量稀释法测定6种抗生素对33株病原菌的最低抑菌浓度.33株临床分离菌株对临床上常用的6种抗生素的平均敏感率为27.7%,平均耐药率为64.8%.对金黄色葡萄球菌抗茵作用最强的是氯霉素,敏感率为82.6%,MIC50为2 mg/L,MIC90为64 mg/L;耐药性最强的是青霉素,耐药率达100%.肺炎克雷伯菌的耐药性较为严重,平均耐药率高达80%,抗茵作用最强的为新霉素,但其敏感率仅为40%.33株临床分离菌株的耐药性较为严重,存在交叉耐药性和多重耐药性现象.     

Genetic mapping and utilization of quantitative trichome-mediated insect resistance in potato

Introgression of trichome-mediated insect resistance from the wild speciesSolanum berthaultii has become a major focus of the potato improvement program at Cornell University during the past twelve years. Several quantitative characters are involved in this resistance which is effective against a wide range of pest types. Correlative biochemical assays have been developed to assay specific components of the resistance, and the effects of the resistance on the target pests have been studied. Quantitative laboratory assays and specific measurements of insect behavior and biology have increased the precision of selection and enable the investigation of the genetic control of the resistance.We are currently using restriction fragment length polymorphisms (RFLPs) for genetic mapping of factors controlling the trichome traits fromS. berthaultii. Backcrosses to both the wild and the cultivated species parents have been evaluated for phenotypes contributing to the resistance mechanism, including trichome density, sucrose ester and polyphenol oxidase production by the trichomes, and the enzymatic browning reaction responsible for insect entrapment. Genetic maps are being developed for these progenies, using RFLP markers previously mapped in potato. Field and greenhouse trials under insect infestations are also being conducted with the mapping progeny. Our goal is to locate genes responsible for quantitative insect resistance by correlating RFLP variation at mapped loci with the trichome phenotypes and insect resistance. Genetic markers for these traits will be useful in transfer of the effective wild chromosomal segments into and among tetraploid potatoes, and for a better understanding of the resistance mechanism.     

Isolation and characterization of antimicrobial-resistant Escherichia coli from national horse racetracks and private horse-riding courses in Korea

Limited information is available regarding horse-associated antimicrobial resistant (AR) Escherichia (E.) coli. This study was designed to evaluate the frequency and characterize the pattern of AR E. coli from healthy horse-associated samples. A total of 143 E. coli (4.6%) were isolated from 3,078 samples collected from three national racetracks and 14 private horse-riding courses in Korea. Thirty of the E. coli isolates (21%) showed antimicrobial resistance to at least one antimicrobial agent, and four of the AR E. coli (13.3%) were defined as multi-drug resistance. Most of the AR E. coli harbored AR genes corresponding to their antimicrobial resistance phenotypes. Four of the AR E. coli carried class 1 integrase gene (intI1), a gene associated with multi-drug resistance. Pulsed-field gel electrophoretic analysis showed no genetic relatedness among AR E. coli isolated from different facilities; however, cross-transmissions between horses or horses and environments were detected in two facilities. Although cross-transmission of AR E. coli in horses and their environments was generally low, our study suggests a risk of transmission of AR bacteria between horses and humans. Further studies are needed to evaluate the risk of possible transmission of horse-associated AR bacteria to human communities through horse riders and horse-care workers.     

基于转录组数据的害虫抗药性综合检测方法

为建立基于转录组数据的害虫抗药性检测方法,以3种重要害虫家蝇Musca domestica、白纹伊蚊Aedes albopictus和小菜蛾Plutella xylostella的8个抗性/敏感种群的转录组数据为对象,使用已开发的乙酰胆碱酯酶抗性突变检测程序ACE检测不同种群中的乙酰胆碱酯酶抗药性突变,并使用Bowtie 2软件和R程序包DESeq2检测其解毒酶基因的表达量变化,分析这3种害虫对有机磷类和氨基甲酸酯类杀虫剂的抗性分子基础。结果显示,在家蝇2个抗性种群KS8S3和ALHF中检测到ace2基因上发生了G227A抗药性突变,突变频率分别为0.318和1.000;在白纹伊蚊抗性种群Tem-GR中检测到CCEae3a基因的表达量较敏感种群Par-GR上调了7.175倍;在小菜蛾抗性种群ZZ中检测到ace1基因上发生A201S和G227A抗药性突变,突变频率分别为0.656和0.692。根据上述突变频率和解毒酶基因表达量变化评估的3种害虫种群抗药性情况与其之前的报道基本相符,表明基于转录组数据同时对靶标抗性机制和代谢抗性机制进行检测的害虫抗药性综合检测方法可以很好地反映害虫种群的抗药性状况。     

三种观赏竹抗旱生理指标的研究及其综合评价

可控条件下研究了三种观赏竹铺地竹、平安竹、小佛肚竹在干旱胁迫下的生理指标变化,即叶片叶绿素、SOD、M DA、质膜透性的含量的变化。根据这些生理生化指标进行了抗旱性综合评价,结果为:平安竹>小佛肚竹>铺地竹。这一结果与三种观赏竹的实际表现是一致的。     

小麦品种对赤霉病的慢病性研究

采用分生孢子悬浮液花期喷雾接种法,在大田研究了12个小麦品种对赤霉病菌的抗病性,系统记载了小麦赤霉病病穗率和发病严重度,计算病情指数并进行曲线拟合,结果表明,小麦赤霉病病情指数发展过程符合Logistic模型。计算AUDPC并进行聚类分析,结果表明,12个小麦品种对赤霉病的抗病性可分为抗病性、慢病性和感病性3种类型。其中陕229、陕213、小偃135和88(1)16-9等品种具有群体慢发抗病性。     

提高转bar基因杂交粳稻大田纯度的试验

在秧田和本田喷施不同浓度除草剂Basta,验证对提高转bar基因杂交粳稻纯度的效果。结果表明,转bar基因恢复系NT-5-1的T6世代仍保持对Basta的抗性;转bar基因杂交稻3～4叶期喷施0.1%～0.2%Basta60kg/667m2,清除假杂种效果均达100%。     

河北省近年审定棉花品种的主要性状评价

分析评价了 1 992年以来河北省审定的 42个棉花品种的产量、抗病性、纤维品质等性状。结果表明 :审定品种的产量水平有所提高 ;枯萎病抗性保持在较高水平 ,黄萎病抗性育种进展缓慢 ;单株铃数、霜前花率略有上升 ;生育期、铃重、衣分相对稳定 ;纤维长度没有明显变化 ,比强度偏低 ,马克隆值基本达标。     

糜子品种抗倒伏试验研究

该文采用倒伏系数和田间倒伏面积对比的方法,对内糜5号、内糜6号、内糜7号、内糜8号、内糜9号、伊选黄糜等6个主栽糜子品种进行了抗倒伏试验研究。结果表明,内糜5号、内糜6号、内糜8号、内糜9号的倒伏系数小于1.0,抗倒伏能力较强,内糜7号和伊选黄糜倒伏系数大于1.0,抗倒伏能力较弱,易发生大面积倒伏现象。在今后的糜子育种工作中,应努力提高糜子单茎根量和茎秆机械强度,降低植株高度,以增强其抗根倒伏能力。