Bovine brucellosis – a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.     

Genetic analysis of quantitative traits across environments in linseed (Linum usitatissimum L.)

Summary Fourteen lines of linseed (Linum usitatissimum L.) were evaluated for general and specific combining ability through line × tester cross analysis using five diverse testers in two different environments. Seventy F₁'s and nineteen parental genotypes were raised in completely randomized block design with two replications with respect to yield and yield related traits. Considerable genetic variation was observed for all the traits studied. The additive as well as non-additive gene effects played significant role in the inheritance of yield and related traits with preponderance of non-additive gene effects for all the traits studied. Higher proportion of general combining ability × environment interaction variance as compared to specific combining ability × environment estimates was recorded. Additive genetic variances were more sensitive than non-additive genetic variances to the changing environment. Low estimates of heritability (narrow sense) for primary branches per plant, capsules per plant, seeds per capsule, seed yield per plant, harvest index and oil content and medium heritability for days to 50% flowering, days to maturity, plant height and 1000-seed weight was observed. Among the female parents LCK-9816, Parvati, Himalini, KL-168 were good general combiners for yield and related traits along with oil content, whereas among male parents, Surbhi and KL-224 were good general combiners for yield related traits and oil content but KL-221 was good general combiner for seed yield and related traits.     

Porcine circovirus-2 DNA concentration distinguishes wasting from nonwasting pigs and is correlated with lesion distribution, severity, and nucleocapsid staining intensity.

The emergence of severe porcine circoviral disease in North America is associated with Porcine circovirus-2 genotype b (PCV-2b), which has led to speculation that PCV-2b is more virulent than PCV-2a. The objectives of this study were to 1) correlate the PCV-2 DNA concentration and lesions in wasting (WST) and age-matched healthy (HLTH) pigs from 2 clinically affected farms, and unaffected (UNFCT) pigs from a farm with no prior clinical or diagnostic history of PCVD; and 2) to determine the initial estimates of sensitivity and specificity of PCV-2 quantitative polymerase chain reaction (qPCR). PCV-2b was confirmed in all 3 farms. Compared with HLTH pigs, WST pigs demonstrated significantly more prevalent thymic atrophy, failure of normal pulmonary collapse, and ascites (P < 0.017 for all). The HLTH and UNFCT pigs had significantly more pronounced lymphoid germinal centers and proliferative paracortical T-dependent zones, compared with WST pigs (P < 0.017). Across all tissues, PCV-2 DNA concentrations were significantly higher in WST compared with HLTH and UNFCT pigs (P < 0.017 for all). The PCV-2 DNA concentrations were strongly correlated with PCV-2 nucleocapsid staining intensity in lymph node, spleen, Peyer's patches, lung, liver, and kidney (0.60 < or = r < or = 0.84). In the current study, the PCV-2 DNA log10 cutoff concentrations best able to distinguish WST from HLTH and UNFCT pigs were between 7.0 and 8.0 per gram for tissues, and between 4.0 and 5.0 per milliliter for sera. The presence of PCV-2b in UNFCT pigs is evidence that PCV-2b by itself is not sufficient to induce severe disease.     

Molecular identification and antibiotic control of bacterial contamination in cultures of ginger (Zingiber officinale)

Zingiber officinale, Rosc., one of the major tropical spices in the world, belongs to the family Zingiberaceae. Bacterial contamination is a major constraint on the cryopreservation of in vitro shoot tip explants. The main objective of this study was to identify the nature of this bacterial contamination and its response to various antimicrobial agents (e.g. the antibiotics cephotaxime and streptomycin sulphate, or copper sulphate) for more effective control. The bacteria isolated from ginger plantlets were identified by amplification and sequencing of their 16S ribosomal DNA, followed by partial sequence analysis. Luteibacter yeojuensis was found in all contaminated cultures. L. yeojuensis is found mainly in soil and as a human pathogen. We believe this is the first report of L. yeojuensis contaminating in vitro cultures of ginger. Among the antimicrobial agents tested in the shoot multiplication medium [i.e. 1.0× Murashige and Skoog salts + 2.5 mg l^–l 6-benzylaminopurine + 3% (w/v) sucrose + 0.45% (w/v) Clarigar^TM], 100 mg l^–1 cephotaxime was most effective at reducing bacterial growth. It also gave the maximum number of shoots per shoot bud explant compared to the same medium supplemented with streptomycin sulphate, or CuSO₄, or control medium. No further bacterial contamination was observed when 8-week-old cultures were then subcultured on the same medium without added antibiotic or CuSO₄.     

黔北麻羊Tβ4基因多态性及生物信息学分析

本研究旨在对黔北麻羊胸腺素β4（thymosin beta 4,Tβ4）基因的多态位点进行筛选及生物信息学分析。根据GenBank中山羊Tβ4基因序列（登录号：NC_030810和NW_017189516）,应用Primer Premier 5.0软件设计引物,运用混合DNA池结合PCR产物直接测序获得黔北麻羊Tβ4基因X染色体第1、2、3外显子和3号染色体第1外显子序列进行多态性分析,利用生物信息学分析软件对黔北麻羊Tβ4基因进行同源性、系统进化树、理化性质、疏水性、卷曲螺旋、跨膜结构、信号肽、亚细胞定位、结构域、磷酸化位点、糖基化位点、二级结构和三级结构分析。结果显示,共筛选出10个SNPs,分别为：G55C、C82T、G112A、C129T、G216A、G431A、G551T、T579A、A609G和A619G。同源性比对分析结果显示,黔北麻羊与黄牛、马、野猪、人、裸滨鼠、褐家鼠、小家鼠和原鸡Tβ4基因核苷酸序列同源性分别为97.8%、96.3%、95.6%、94.1%、94.8%、91.1%、92.6%和86.7%。蛋白理化性质分析显示,黔北麻羊Tβ4蛋白理论等电点为5.02,亲水值最小为-3.011,无疏水性氨基酸,无卷曲螺旋,不是跨膜蛋白,无信号肽存在,分布在细胞核（60.9%）、线粒体（4.3%）、细胞骨架（17.4%）和细胞质（17.4%）,有1个THY结构域,有1个苏氨酸磷酸化位点,无N糖基化位点,有4个O糖基化位点。二级结构分析显示,C129T突变使其蛋白质二级结构中α-螺旋增加,无规则卷曲减少。本研究成功筛选出黔北麻羊Tβ4基因多态位点,为研究黔北麻羊育种的分子遗传标记辅助选择提供了参考依据。     

紫色土区植物篱对坡面土壤微生物特性的影响

土壤微生物是土壤的重要组成部分,对土壤肥力的形成和植物营养的转化起着积极的作用,是土壤肥力和环境变化的重要指标。通过土壤微生物量测定,研究新银合欢植物篱对紫色土区坡地农耕地、经济林地2种土地利用方式及10°,15°坡度下0-20cm土层土壤微生物特性的影响。研究发现：新银合欢植物篱可以明显提高土壤中细菌、放线菌、真菌的数量及微生物量碳、氮含量;植物篱对经济林地小区土壤微生物数量,微生物量碳、氮的影响作用总体上大于对农耕地小区的,同时对10°农耕地的影响作用总体上大于对15°农耕地的;下坡的三大微生物数量,土壤微生物量碳,氮平均含量明显比上坡的多,下坡距离植物篱带最近采样点处三大微生物数量,土壤微生物量碳,氮含量明显比其他采样点的多。表明定植新银合欢植物篱有利于减少土壤肥力衰退,有利于土壤碳、氮素固持。     

Resistance to bean common mosaic potyvirus strains and its inheritance in some Indian land races of common bean

Evaluation of 397 common bean accessions of diverse origin revealed the presence of effective sources of resistance against bean common mosaic potyvirus strains prevalent in Himachal Pradesh, a north-western Himalayan state of India. 21 accessions viz., KR 7, KR 225, KR 295, KRC 4, KRC 7, KRC 11, KRC 12, KRC 13, KRC 16, KRC 22, Amanda, Black Turtle Soup, Contender, Hans, Great Northern UI 123, Improved Tender Green 40031, Jubila, Kentucky wonder, Monroe, Premier and Sanilac, were found resistant to NL-1n and NL-7n strains. Some of the genotypes showed strain specific resistance. Pattern of inheritance studied in Hans, Contender, KRC 4 and KRC 22 of Indian origin against strain NL-1n revealed that single dominant gene governed the resistance in Hans and Contender whereas single recessive gene determined the resistance in KRC 22 and KRC 4. SCAR marker SW13₆₉₀ amplified a product of 690 bp in Hans and Contender, confirmed the presence of I gene in these cultivars. The implications of above genes in breeding for programme for BCMV resistance are discussed.     

特色蔬菜芦笋的特性特征、价值及发展前景

芦笋营养丰富,并含有很高的医疗保健成分,已成为当今社会流行的一种名贵蔬菜。随着人们生活水平的不断提高,国内食用芦笋产品的人也越来越多,因此芦笋产品在国内外十分畅销。芦笋生产已成为我国高产、高效、创汇农业和促进农村经济发展的重要产业。     

黔北麻羊UCP2基因组织表达及其多态性与生长性状的关联分析

本研究旨在探讨黔北麻羊解耦联蛋白2（uncoupling protein 2,UCP2）基因的遗传多态性及其与生长性状的关联性,以期为黔北麻羊的育种改良提供理论依据。以200头6月龄黔北麻羊为研究对象,采用直接测序法检测黔北麻羊UCP2基因的SNP位点,并将其与黔北麻羊生长性状进行关联分析;实时荧光定量PCR检测UCP2基因在黔北麻羊不同组织中的表达水平。结果显示,UCP2基因存在4个SNPs位点,分别为：g.29614172 A>G、g.29619320 G>T、g.29619721 C>T和g.29620037 A>G,均产生3种基因型,其中g.29619320 G>T和g.29620037 A>G为错义突变,g.29619320 G>T突变导致甘氨酸（Gly）变为半胱氨酸（Cys）,g.29620037 A>G突变导致苏氨酸（Thr）突变为丙氨酸（Ala）。多态信息含量显示,4个SNPs位点均表现为中度多态（0.25 < PIC < 0.5）。χ²检验结果表明,g.29614172 A>G、g.29619721 C>T和g.29620037 A>G突变位点在黔北麻羊群体中均处于Hardy-Weinberg平衡状态（P>0.05）,g.29619320 G>T突变位点极显著偏离了Hardy-Weinberg平衡状态（P<0.01）。连锁不平衡分析显示,g.29619320 G>T和g.29619721 C>T位点具有强连锁效应。实时荧光定量PCR结果表明,UCP2基因在黔北麻羊各组织中均有不同程度的表达,其在肺脏中的表达量最高,其次是脾脏、肝脏和心脏,其余组织表达量较低。关联性分析结果表明,g.29614172 A>G位点AG和GG基因型个体体重、体斜长、胸宽、胸深、胸围及管围均显著高于AA基因型,g.29619320 G>T位点TT基因型个体胸深、胸围及管围均显著高于GT和GG基因型,g.29619721 C>T位点CT基因型个体体高显著高于CC和TT基因型,g.29620037 A>G位点GG基因型个体体重、胸深及管围均显著高于AG和AA基因型个体（P<0.05）。本试验结果初步揭示UCP2基因对黔北麻羊部分生长性状有显著影响,发现的4个SNPs位点可作为黔北麻羊经济性状选择的遗传标记。     

Pyramiding of two bacterial blight resistance and a semidwarfing gene in Type 3 Basmati using marker-assisted selection

A traditional Type 3 Basmati rice cultivar grown in India is tall and lodges even under low nitrogen fertilizer dose. In addition to lodging, it is highly susceptible to several diseases and pests including bacterial blight (BB). BB resistance genes (Xa21 and xa13) and a semidwarfing gene (sd-1) were pyramided in Type 3 Basmati from a rice cultivar PR106-P2 using marker-assisted selection (MAS). Foreground selection for BB resistance genes, Xa21 and xa13 and reduced plant height gene, sd-1 was carried on the basis of linked molecular markers pTA248, RG136 and ‘h’, respectively. The BC₂F₃ progenies with both the BB resistance genes were highly resistant with lower lesion length than either of the genes individually. Background profiling of the selected 16 BC₂F₃ progenies was done using 95 anchored SSR and 12 ISSR markers. Among the selected 16 BC₂F₃ progenies, 38-5-2 and 38-5-36 closely clustered along with the recipient parent Type 3 Basmati showing above 85% genetic similarity with the same. Further selection was continued till F₅ generation for higher recovery for Type 3 Basmati characteristics. The desirable alleles of intermediate amylose content (wx) and aroma (fgr) loci of Type 3 Basmati were also tracked using the linked SSR markers. The BC₂F₅ pyramid lines T3-4, T3-5, T3-6 and T3-7 homozygous for the three target genes Xa21, xa13 and sd-1 from the donor parent with wx and fgr alleles of Type 3 Basmati had excellent cooking quality and strong aroma.