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1.
凉山黑绵羊是我国十大优异畜禽遗传资源之一。通过问卷调查、实地调研和查阅资料等方式,发现近年来凉山黑绵羊产业得到了前所未有的发展,但疫病防控也面临着羊病流行情况复杂、免疫效果不佳、疫病监测预警能力弱等诸多短板,由此提出提高疫病综合防控能力和养殖户疫病防控意识,优化科学合理的免疫程序,加强监测预警能力建设,科学防治寄生虫病等防控策略,旨在提升凉山黑绵羊产业疫病防控能力,助力乡村振兴,保障国家核心畜禽种源安全。  相似文献   
2.
甜樱桃(Prunus avium)和酸樱桃(Prunus cerasus)分步微繁技术,此技术涵盖了微繁全过程所需的全套技术,包括外植体和培养基的制备方法,各个阶段的培养技术及培养基配方、试管苗炼苗和移栽等,采用这一技术体系,可在30周内完成从芽外植体建立到温室植株的全过程。此外,还提出了进一步改进该技术体系的建议,如调整总氮量及NO3^-/NH4^ 比率,添加蔗糖以外的其他碳源,优化BAP和IBA浓度及配比率。  相似文献   
3.
The phenolic profile of strawberry fruits (Fragaria x ananassa Duch., Rosaceae) was investigated by high-performance liquid chromatography with photodiode array detection. A peak displaying retention time and UV spectral data identical to those of phloridzin (phloretin 2'-O-beta-d-glucoside), a dihydrochalcone glucoside so far considered characteristic of apples, was monitored. For further characterization, crude extracts of strawberries were purified on polyamide, and the target compound was isolated by preparative and analytical HPLC. Structure elucidation was performed on the basis of APCI- and ESI-MS in the negative ion mode as well as by 1D and 2D NMR spectroscopy using authentic phloridzin for comparison. The d-configuration of the sugar moiety was established by HPLC analysis of the corresponding acyclic 1-deoxy-1-(N-acetyl-alpha-methylbenzylamino)alditol acetate. Apart from its chemotaxonomic relevance, this first report on the occurrence of phloridzin in strawberries is of particular interest for the authenticity control of strawberry products such as juices, jams, and fruit preparations since phloridzin has so far been used for the detection of fraudulent admixtures.  相似文献   
4.
Aphanomyces euteiches Drechsler is an oomycete pathogen of leguminous crops that causes root rot, a severe disease of pea (Pisum sativum L.) worldwide. An improved understanding of the genetic structure of A. euteiches populations would increase knowledge of pathogen evolution and assist in the design of strategies to develop pea cultivars and germplasm with stable disease resistance. Twenty six primers pairs were used to amplify Sequence Related Amplified Polymorphisms (SRAP) among 49 A. euteiches isolates sampled from pea. A total of 190 polymorphic SRAP bands were generated, of which 82 were polymorphic between all the A. euteiches isolates. The percentage of polymorphic bands per primer pair ranged from 22 to 75%. According to the PIC value estimated for each marker, 60% of the SRAP markers were highly to reasonably informative (PIC > 0.25). Genetic structure of A. euteiches populations sampled in different American and French locations showed low to high genetic diversity within populations. The largest variation occurred within countries, with a total estimated genetic diversity of 0.477 and 0.172 for American and French populations, respectively. This was particularly evident from a principal component analysis (PCA) and a Minimum Spanning Networks (MSN) based on genetic profiles of isolates, which generated two different clusters, one corresponding to the French isolates and four American isolates (MV1, MV5, MV7, Ath3), and the other to American isolates. A. euteiches populations from cultivated pea in France appeared as a single unstructured population, whereas American isolates of A. euteiches diverged into three different populations.  相似文献   
5.
磁珠富集法分离柿微卫星标记   总被引:2,自引:0,他引:2  
【目的】分离柿属植物的微卫星标记,为柿种质资源的分类、进化等遗传研究奠定基础。【方法】提取磨盘柿(Diospyros kaki)基因组DNA后,用EcoRⅠ和MesⅠ2种内切酶酶切并连接接头,再用接头特异引物进行PCR扩增。扩增产物与生物素标记的(GA)15和(AC)15探针杂交,杂交复合物用链亲和素包裹磁珠进行结合,得到单链DNA目标片段,经PCR扩增,连接pGEM-T载体,转化入感受态大肠杆菌,得到微卫星富集小插入片段DNA文库。用Colony-PCR法筛选阳性克隆,进行测序分析。【结果】测序96个克隆,54个含微卫星序列,24个为有效微卫星序列,其中完美型(perfect)9个,占37.5%;非完美型(imperfect)7个,占29.2%;混合型(compound)8个,占33.3%(。GA)n重复最为常见。21条含微卫星序列已登录GenBank(Accession Number:EF567396~EF567416)。成功设计21对引物,经初步筛选,14对表现出多态性。【结论】试验方法分离柿基因组微卫星简便有效,得到的多态性引物可用于柿种质资源的遗传研究。  相似文献   
6.
核桃 (Juglansregia)‘No . 12 0’品系授粉 7~ 8周的幼胚胚轴与子叶在含不同植物生长调节剂组合的诱导培养基上培养 4周后转移至无植物生长调节剂的继代培养基上培养 ,不同发育时期的体细胞胚直接形成于胚轴与子叶表面。子叶与胚轴分别在KT 2mg/L BA1mg/L IBA 0 .0 1mg/L与 2 ,4 D 2mg/L KT 1mg/L的组合的诱导下体细胞胚胎发生频率最高。体细胞胚经 3~ 5℃低温处理 2个月 ,31.6%的体细胞胚能发育成正常生长的植株  相似文献   
7.
OBJECTIVE: To determine serum lipase activities and pancreatic lipase immunoreactivity (PLI) concentrations in dogs with exocrine pancreatic insufficiency (EPI). ANIMALS: 74 healthy dogs and 25 dogs with EPI. PROCEDURES: A diagnosis of EPI was made on the basis of clinical signs, low serum trypsin like immunoreactivity (TLI) concentration, and response to treatment with enzyme replacement. Median values for fasting serum lipase activity and serum PLI concentrations were compared between the 2 groups with a Mann-Whitney U test. RESULTS: Median fasting serum lipase activity was not significantly different between dogs with EPI (366.0 U/L) and healthy dogs (294.5 U/L), and only 1 dog with EPI had a serum lipase activity less than the lower limit of the reference range. Median serum PLI concentration was significantly lower in dogs with EPI (0.1 microg/L) than in healthy dogs (16.3 microg/L). All dogs with EPI had serum PLI concentrations less than the lower limit of the reference range. CONCLUSION AND CLINICAL RELEVANCE: Serum lipase activity is not limited to the exocrine pancreas in origin, whereas serum PLI is derived only from the exocrine pancreas. Unlike in serum TLI concentrations, there was a small degree of overlap in serum PLI concentrations between healthy dogs and dogs with EPI. Serum TLI concentration remains the test of choice for diagnosis of EPI.  相似文献   
8.
通过农杆菌介导法将哈兹木霉几丁质酶ThEn-42基因导入核桃   总被引:17,自引:0,他引:17  
 通过根癌农杆菌C58C1 ATHV RifR介导法, 利用烟草花叶病毒35 S 双启动子和苜蓿花叶病毒引导序列控制下的含抗新霉素磷酸转移酶基因(npt Ⅱ) 和哈兹木霉几丁质酶基因(ThEn-42) 的质粒pBin19ESR 为载体, 对3 个核桃体细胞胚系进行遗传转化, 结果获得41 个抗卡那霉素的体细胞胚系。经PCR 和复式PCR 检测, 41个转化系均含有nptⅡ基因, 其中38个转化系含有ThEn-42 基因。Southern 杂交分析表明, ThEn-42基因已被整合到核桃体的基因组中。几丁质酶活性检测结果表明, 转化的体细胞胚系的几丁质酶活性比对照高几十至几千倍。遗传转化的体细胞胚系已萌发成苗。  相似文献   
9.
At periods greater than 1000 seconds, Earth's seismic free oscillations have anomalously large amplitude when referenced to the Harvard Centroid Moment Tensor fault mechanism, which is estimated from 300- to 500-second surface waves. By using more realistic rupture models on a steeper fault derived from seismic body and surface waves, we approximated free oscillation amplitudes with a seismic moment (6.5 x 10(22) Newton.meters) that corresponds to a moment magnitude of 9.15. With a rupture duration of 600 seconds, the fault-rupture models represent seismic observations adequately but underpredict geodetic displacements that argue for slow fault motion beneath the Nicobar and Andaman islands.  相似文献   
10.
Zusammenfassung 1. Die amerikanische ErdbeerblattlausPentatrichopus fragaefolii, die als der wichtigste Virusüberträ ger bei der Erdbeere gilt, ist in den Südwest- und Westdeutschen Erdbeeranlagen weit verbreitet. Nach den bisherigen Erfahrungen weicht ihr Massenwechsel in diesem Gebiet von dem in anderen westeuropäischen Lä ndern ab. In England und Holland werden gewöhnlich zwei Perioden mit einer starken Vermehrung der Laus beobachtet, in der Bundesrepublik dagegen nur eine im Herbst.2. Die günstigsten Termine zur Bekämpfung des Schädlings sind bei uns im Frühjahr und Herbst gegeben. Zu dieser Zeit durchgeführte Metasystox-Spri{ie151-01}ungen ergaben eine starke Reduktion des Blattlausbesa{ie151-02}es in einem stark befallenen Erdbeerfeld und verhinderten die rasche Virusverseuchung einer gesund erstellten benachbarten Erdbeeranlage.
Summary 1. The strawberry aphidPentatrichopus fragaefolii, well-known as the most important vector for strawberry viruses, is widespread in fields southwest and west of West Germany. From the experiences up to now its population in these areas differs from those in other European countries. In England and the Netherlands two periods with a high increase are commonly observed, whilst in West Germany there is only one in autumn.2. The best times of the year to control the aphid are spring and autumn in West Germany. Sprayings with metasystox carried out at these times effected not only a considerable reduction of the number of aphids in a badly infected strawberry field, but also prevented a quick spread of virus into an adjacent strawberry field which has been established with healthy plants.
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