犬细小病毒南京分离株基因型分析

采用PCR技术对不同来源的犬细小病毒毒株进行了基因型鉴定,发现所鉴定的1982~2004年的5株犬细小病毒南京分离株和荷兰Intervet疫苗株(CPV-V154)均为CPV-2b亚型,而且相互之间的同源性均高于98.4%。     

不同基因型新城疫病毒强毒株对鸡的致病性

就不同基因型新城疫病毒强毒株对鸡的致病性进行了比较。用3种基因型（Ⅵg、Ⅶd亚型、Ⅸ型）新城疫病毒强毒株分别人工感染25日龄雏鸡，结果各株病毒接种鸡均100％发病、100％死亡，表现出嗜内脏型新城疫病毒感染引起的典型的新城疫症状和病理变化。免疫组化检测发现．攻毒鸡多种组织器官中能检测到病毒抗原，在能检测到病毒抗原的器官中，病毒抗原主要定位于淋巴细胞、网状细胞、巨噬细胞、肝细胞及各种上皮细胞的胞浆内；新城疫病毒对肠相关淋巴组织的亲嗜性优先于附近的上皮。本试验结果表明．基因Ⅵg、Ⅶd亚型、Ⅸ型新城疫病毒强毒株对鸡均具有高度致病性。     

Variation in virus populations and growth characteristics of two sugarcane cultivars naturally infected by Sugarcane yellow leaf virus in different geographical locations

Two sugarcane cultivars (R570 and SP71-6163) naturally infected by Sugarcane yellow leaf virus (SCYLV) were each imported from several geographical locations into a sugarcane yellow leaf-free environment (Montpellier, France). Plants were grown as plant cane for 5–6 months and the experiment was repeated for three consecutive years (2003–2005) in a greenhouse. Several sugarcane-growth and disease characteristics were monitored to identify variation in pathogenicity of SCYLV. Depending on their geographical origin, sugarcane cvs R570 and SP71-6163 were infected by SCYLV genotypes BRA-PER or REU, or a mixture of the two. Severity of symptoms did not vary between plants of cv. R570, but variation in disease severity between plants of cv. SP71-6163 from different geographical locations suggested the occurrence of pathogenic variants of SCYLV. For each sugarcane cultivar, differences in stalk length, number of stalk internodes, virus titre in the top visible dewlap leaf, and percentage of infection of leaf and stalk phloem vessels were also found between plants from different geographical origins. However, these differences were not always reproducible from one year to another, suggesting occurrence of different plant responses to SCYLV isolates under varying environmental conditions.     

雪花梨及其亲缘品种S基因型的确定

梨是典型的自交不亲和性果树,自然授粉结实率低,品质差。通过确定梨品种S基因型可寻找简便快速克服自交不亲和性,提高产量,改良品质的方法。根据梨S基因的一级结构特点,利用S基因的保守序列设计特异引物,并对雪花梨及其亲缘品种的基因组DNA进行PCR扩增。将基因组特异扩增电泳只显示一条S基因带雪花梨的特异扩增片段回收并与T载体连接,转化至大肠杆菌中。取其中1个阳性克隆进行测序,并通过生物信息学软件分析确定其核苷酸序列,推导出氨基酸序列,经网上Blast比较,确定该雪花梨S基因片段的S基因型,然后就该S基因进行酶切系统分析,有针对性地挑取另一个阳性克隆测序分析。另外,通过品种间的亲缘关系并经过酶切检测以分析雪花梨亲缘品种的S基因型,并确定各品种的S基因型分别为:雪花S4S16、冀蜜S1S16、雪青S3S16、雪峰S4S16、雪英S3S16、雪芳S4S16。     

采收期、贮藏温度和贮藏时间对不同基因型甜玉米品质的影响

对不同采收期、不同贮藏温度和贮藏时间的超甜(sh_2)、普通甜(su_t)和加强甜(su_1se)玉米杂交种以及大田玉米杂交种的还原糖含量、蔗糖含量、水溶多糖(WSP)含量以及水分含量等进行分析发现,在甜玉米类型中 sh_2杂交种在各个采收期总糖含量都是最高,su_1se次之,su_1最低。但 su_1的 wsp 含量最高,su_1se 与之接近,sh_2最低,与普通玉米相同。以糖分和水分为根据,认为普通甜玉米的合适采收期为授粉后18～26天,积温为306.2℃～420.2℃,加强甜玉米可以适当放宽,但超甜玉米合适采收期应在授粉20天之后。三种甜玉米在28℃下贮藏,糖分和水分含量都迅速降低,但超甜玉米有较强的保鲜能力。在4℃条件下贮藏一周,普通甜玉米和加强甜玉米糖分含量只降低10%,超甜玉米虽然降低了25.8%,但含糖量还保持在35%以上,说明低温贮藏对保持甜玉米的优良品质是十分重要的。     

单双低黄籽白菜型优质油菜良种繁育体系技术报告

根据白菜型油菜的遗传特点,对其繁育保质技术进行了系列研究和探讨.初步设计出单双低白菜型油菜良种繁育技术体系,并经大面积繁种验证,取得较好的效果.     

黑龙江省马铃薯晚疫病菌的交配型和multi-locus基因型分析

2015~2017年在黑龙江省哈尔滨市、绥化市和齐齐哈尔市各马铃薯主产区共采集分离了126株马铃薯晚疫病菌菌株,测定交配型、mtDNA单倍型、SSR基因型并进行multi-locus基因型分析。结果显示,126株菌株中发现了A1、A2、自育型3种交配型,分别占分离菌株总数的88.1%、6.3%和5.6%。126株菌株中共鉴定出Ⅰa和Ⅱa两种mt DNA单倍型,分别占分离菌株总数的17.5%和82.5%。126株菌株中共鉴定出7种SSR基因型,分别为F-01、F-02、F-03、F-05、F-06、D-03和G-02,其中F-01基因型(77.8%)为优势基因型。根据马铃薯晚疫病菌的mt DNA单倍型和SSR基因型,共划分了9种multi-locus基因型,其中multi-locus基因型A(65.1%)是黑龙江省发现的优势基因型。2015~2017年黑龙江省马铃薯晚疫病菌群体结构逐年复杂,绥化市马铃薯晚疫病菌群体结构最为复杂。     

青海省海北地区牦牛源贾第虫检测与基因型分析

为研究青海省海北地区牦牛贾第虫的感染情况及虫种基因型,对青海省祁连县、海晏县和刚察县的297份牦牛粪样采用蔗糖密度梯度离心法纯化,之后用免疫荧光方法对贾第虫进行鉴定,对阳性及疑似阳性样品采用基于18SrRNA和谷氨酸脱氢酶(gdh)基因的套式PCR扩增,并对扩增产物进行测序。将测序结果与GenBank中的贾第虫序列进行比对分析。免疫荧光抗体试验结果显示,共检出24份贾第虫阳性粪样,总阴性率为8.1%。套式PCR扩增结果显示,24份阳性样品中18SrRNA基因扩增阳性22份,gdh基因扩增阳性18份,产物大小分别为292bp和432bp。序列分析表明,分离的虫种均为牦牛源肠贾第虫,基因型为集聚体E,未发现人畜共患基因型。     

Resistance Analysis and Genotype Detection of ESBLs-producing Swine E.coli Strains in Parts of Guizhou Province

To find out the drug resistance and the distribution and prevalence of ESBLs genotypes of E.coli strains on scale pig farms in Guizhou, the antimicrobial susceptibility of 164 E.coli strains were determined.And the genotype of ESBLs was identified and determined by CLSI standard method, DNA was amplified and the 4 genotypes of drug resistance plasmid of ESBLs were analyzed by PCR.The results showed that the drug resistance rates of 164 E.coli strains to ten kinds of antimicrobial agents were ceftiofur 93.29%, ampicillin 87.19%, tetracycline 86.59%, gentamicin 81.10%, streptomycin 53.66%, polymyxin 51.83%, ciprofloxacin 53.05%, kanamycin 47.56%, chlortetracycline 34.76% and florfenicol 21.95%, respectively, and most of them were multiple drug resistance strains, during which there were 137 strains ESBLs positive, detection rate was 83.54%, and the detection rates of 4 regions were different.The detection rates of TEM, CTX-M-1, SHV and OXA-1 genes of 137 ESBLs-producing E.coli strains were 90.51%, 70.07%, 51.82% and 43.07%, respectively.And the detection rates were various in 4 regions.The results showed that the drug resistance of E.coli strains from scale pig farms was serious in Guizhou, and the detection rate of ESBLs strains was very high, the drug resistance gene detection rate was extremely high, and most drug resistance strains were the composite genotype drug resistant.To prevent and cure colibacillosis in veterinary clinic effectively, we should reinforce monitoring and studying about the ESBLs-producing drug resistance bacteria.     

Characterisation of cultivated breeding lines of eggplant (Solanum melongena L.) and related wild Solanum species from India

Immature fruit of cultivated species of eggplant (Solanum melongena L.) are commonly used as a summer vegetable in India. Rich morphological variation exists among the cultivated species of eggplant in different growing regions of the country. We have characterised 24 breeding lines of Solanum spp., including 20 eggplant cultivars and four wild species of eggplant, based on 13 morphological characters using Mahalonabis D² statistics. All 24 breeding lines of Solanum spp., including the 20 eggplant cultivars and four wild species, were grouped into four clusters by agglomerative clustering. Cluster II and Cluster IV contained the most accessions (eight each), while Cluster I and Cluster III had four accessions each. The highest inter-cluster (D²) distance (158.33) was observed between Cluster I and Cluster II, followed by Cluster I and Cluster III (108.48), and Cluster II and Cluster IV (102.96), which indicated that accessions in Cluster I and Cluster II were more divergent than those in the other clusters. The highest intra-cluster distance (5.80) was observed in Cluster IV, with eight genotypes, and the lowest intra-cluster distance (2.21) was observed in Cluster II, also with eight genotypes. The intra-cluster distances in all four clusters were lower than the inter-cluster distances, which indicated that genotypes within the same cluster were closely related. Genotypes in Cluster IV had the maximum number of flowers per cluster (3.63), the highest number of fruit per cluster (3.25), and number of fruit per plant (208.63), which revealed that genotypes could be selected from Cluster IV for these characters. The first three principal components (PC1, PC2, and PC3) accounted 73.99% of the total variation among the 24 genotypes. These phenotypic data increase the feasibility of prioritising breeding lines in a crossing programme based on the uniqueness of their desirable morphological traits.