Prevalence of sarcocysts of Sarcocystis capracanis in oesophagus and tail muscles of naturally infected goats

The prevalence of sarcocysts of Sarcocystis capracanis in oesophagus and tail muscles of 76 goats slaughtered at Jabalpur, India, was found to be 67.10 and 46.05%, respectively. A total of 79.3% of oesophagi and 72.4% of tails had sarcocysts in older goats (greater than 1 year), but their prevalence in younger animals (less than 1 year) was 40.0% in oesophagi and none in tails. Therefore examination by biopsy of the tail muscles can be used to monitor the development of Sarcocystis sarcocysts in experimental infection without killing the animal.     

Hematological Characteristics of the BB Wistar Rat

Complete blood counts, differential white blood cell and platelet counts were performed on male and female BB Wistar diabetic rats (BBWd), their nondiabetic siblings (BBWnd) and outbred Wistar rats of the line from which the BB Wistar rats were derived. Most of the observed changes were strain-related (those present in both BBWd and BBWnd but not in control rats) rather than diabetes-related (those in BBWd but neither BBWnd nor control rats) and therefore probably due to the inbreeding process. The BBW strain had significantly lower numbers of white cells and platelets, as well as markedly changed differential white cell counts. Differential counts showed a pattern of lymphopenia, neutrophilia, monocytosis and eosinophilia. It is possible that these white blood cell changes contribute to the increased susceptibility to infection reported for the BBW strain. No significant difference in serum immunoglobulin concentrations was found in any of these three groups of rats. There- fore, hypogammaglobutinemia cannot account for the increased susceptibility to infections, but it is not possible to rule out an abnormality in the distribution of immunoglobulin fractions as an etiological factor.     

肽与瘤胃微生物间的关系研究

<正>自从Chen等发现奶牛瘤胃液内肽不足是限制瘤胃微生物生长的主要因素以来,经过多年的理论发展和实践检验,肽营养研究使得传统动物营养学的一些理论观点和体系面临着挑战,重大突破可能由此产生(Webb等,1990、1992)。尤其是传统动物营养认为的"蛋白质必须降解为游离氨基酸后才能被动物利用和吸收"的观点受到了前所未有的质疑。肽作为一种蛋白降解的中间产物,能改变瘤胃中的某些微生态系统,从而有可能使其朝向更有利于人类的方向发展,     

Genetic variability and pathogenicity of Rhizoctonia solani associated with black scurf of potato in New Zealand

Isolates (a total of 129) of Rhizoctonia solani were collected from black scurf on potato tubers from different potato‐growing regions in New Zealand. Sequence analysis of the nuclear ribosomal DNA internal transcribed spacer (rDNA–ITS) regions from these isolates identified three anastomosis groups (AGs), AG‐3PT, AG‐2‐1 and AG‐5. Isolates classified as AG‐3PT were widely distributed, whereas AG‐2‐1 and AG‐5 were confined to distinct locations. Sequence heterogeneity was identified in the ITS regions of 100 AG‐3PT and AG‐2‐1 isolates. Variation in the sequence and length of the rDNA–IGS1 region was also observed for selected isolates of AG‐3PT and AG‐2‐1. Phylogenetic studies found all AG‐2‐1 isolates belong to AG‐2Nt, a subset of AG‐2‐1 previously associated with solanaceous crops in other countries. AG‐2‐1 isolates were consistently more aggressive than those of AG‐3PT. Delayed emergence, severe infection on stolons, formation of aerial tubers and considerable yield losses were associated with AG‐2‐1, but they caused negligible black scurf. In contrast, AG‐3PT caused black scurf on progeny tubers but variable effects on stem emergence and stolons. Furthermore, AG‐2‐1 isolates caused severe tuber malformation, but isolates of other AGs did not. This is the first report on the AG composition, genetic variability and pathogenicity of R. solani isolates associated with black scurf of New Zealand potatoes.     

Integrated control of fusarium head blight and deoxynivalenol mycotoxin in wheat

Fusarium head blight (FHB), a devastating disease that affects wheat, is caused by a complex of Fusarium species. The overall impact of Fusarium spp. in wheat production arises through the combination of FHB and mycotoxin infection of the grain harvested from infected wheat spikes. Spike infection occurs during opening of flowers and is favoured by high humidity or wet weather accompanied with warm temperatures. Available possibilities for controlling FHB include the use of cultural practices, fungicides and biological approaches. Three cultural practices are expected to be of prime importance in controlling FHB and the production of mycotoxins: soil preparation method (deep tillage), the choice of the preceding crop in the rotation and the selection of appropriate cultivar.     

Health and mineral nutrition status of yaks in southern Mustang,Nepal

Biochemical values and mineral concentrations in blood plasma were investigated to evaluate the statuses of health and mineral nutrition among yaks in Mustang District, Nepal. In total, 118 plasma samples of female yaks collected in April and September/October of 2013–2015 were offered. Seventy‐four percent of yaks showed lower plasma total‐cholesterol concentrations than the lowest limit of reference range (100 mg/dL) and the values in spring (83.41 mg/dL) were lower (P < 0.05) than those in autumn (95.05 mg/dL). All the yaks had lower plasma albumin concentrations than the lowest limit of reference range (3.0 g/dL) and 66% of yaks showed lower plasma inorganic phosphorus concentrations than the critical level of phosphorus deficiency (4.5 mg/dL). Thirty‐five percent of yaks showed lower plasma calcium concentrations than the lowest limit of normal range (8 mg/dL) and the concentrations were lower in spring than in autumn (P < 0.01). Seventy‐five percent of yaks presented lower copper concentrations than the critical level (0.65 mg/L) and the concentrations were lower in spring than in autumn (P < 0.01). Since the low plasma total‐cholesterol might have indicated shortage of dry matter and energy intake, attention should be paid to the nutritional statuses of energy, phosphorus, calcium and copper in winter and early spring.     

Hierarchical models for white mould in snap bean

Limitations on the acceptable proportion (incidence) of pods with white mould may lead to the rejection of entire fields of processing snap bean. The low tolerances (no more than 2% to 6% of pods with white mould) are difficult to estimate with sufficient precision in the field when time is limited. These constraints motivated this study of white mould across three spatial hierarchical levels: pods, plants and quadrats consisting of two adjacent plants within rows. Hierarchical relationships are required when designing formal rules for estimating the incidence of pods with white mould from units higher in the spatial hierarchy. Disease assessments were made on all pods from 38 within‐row transects of 40 plants each of the snap bean cultivar Hystyle. Using probability‐based principles, equations were derived and fitted to data on the incidence of white mould on pods (i_pod), plants (i_pad) and quadrats (i_q(2)), which led to a function directly linking i_pod to i_q(2). The variance of i_pod increased with i_q(2), but that may be of little consequence at the lower values of i_q(2) likely to be associated with i_pod values at processor‐set tolerances. For example, at i_q(2) = 0.1 there was a 92% probability that i_pod was less than 0.02. Assessing i_q(2) may be more efficient than directly estimating i_pod because i_q(2) was about an order of magnitude higher than i_pod. Results suggest it may be feasible to design sampling plans for estimating the proportion of pods with white mould from an assessment of the proportion of diseased quadrats.     

无叶假木贼叶绿体基因组特征系统发育及密码子偏好性分析

目的 分析无叶假木贼叶绿体基因组结构特征,阐明假木贼属在藜科中的分类地位,进一步探究其密码子偏好性和确定最优密码子。 方法 基于CTAB法从无叶假木贼幼嫩同化枝中提取总DNA;通过Illumina Genome Analyzer HiSeq 2000高通量测序平台进行测序;使用GetOrganelle和Plann对叶绿体基因组序列进行组装和注释;利用MISA对叶绿体基因组中简单重复序列（SSR）进行分析;使用MAFFT v. 7. 450和IQ-TREE v. 2. 1. 1软件进行多序列比对、构建最大似然法（Maximum likelihood,ML）系统进化树;使用DnaSP 6. 0软件计算核苷酸多态性值;通过CUSP和Codon W 1. 4. 2软件进行密码子偏好性研究。 结果 无叶假木贼叶绿体基因组全长为154 084 bp,包括1个大单拷贝区（LSC,85 124 bp）、1个小单拷贝区（SSC,18 934 bp）、1对反向重复序列（IRa和IRb,25 013 bp）。共注释到132个基因,包含83个蛋白编码基因,8个rRNA基因,37个tRNA基因和4个假基因。SSR位于基因间区的数量最多（70.4%）,单碱基（A/T）重复类型SSR数量最多。系统发育树的最优构树模型为TVM + F + R3,藜科划分为4个聚类组,其中,无叶假木贼与梭梭属和猪毛菜属亲缘关系最近。trnS-trnG(exon1)、ndhF-rpl32、rpl32-trnL、rps16(exon1)-trnQ和ycf1是高核苷酸多态性区域。共确定20个最优密码子（UUU、UAU、UGU、CAU、UCU、UCA、UUA、CUU、CCU、AGA、GAA、ACU、ACA、AAU、GAU、AAA、GUU、GCU、GGU、CAA）,均以A/U结尾,密码子使用偏好性主要受自然选择影响,突变等影响因素对其影响较弱。 结论 无叶假木贼叶绿体基因组结构保守,呈典型的四分体结构。在藜科的系统发育中,无叶假木贼与梭梭属和猪毛菜属亲缘关系最近。鉴定的高变区和SSR位点可用于藜科属间物种的分子鉴定。无叶假木贼叶绿体基因组密码子偏好以A/U结尾,确定的20个最优密码子有助于其外源密码子的优化。研究结果可为无叶假木贼分子标记开发、系统进化及叶绿体基因工程研究提供参考。