不同辣椒种质对象耳豆根结线虫的抗性评价

近年来象耳豆根结线虫的危害日益严重.为筛选抗象耳豆根结线虫的辣椒种质,本试验利用种属特异性引物对根结线虫病原物开展分子鉴定,确定为象耳豆根结线虫.接着采用室内人工接种法,对10份一年生辣椒种质和10份中国辣椒种质进行象耳豆根结线虫抗性鉴定,计算根结指数和卵粒指数,并通过比较隶属函数,发现其中3份辣椒种质对象耳豆根结线虫表现为高抗,抗病性最强的是L518M和L525-1M,L42M次之;10份表现为中抗;7份表现为感病,抗病能力最弱的是L69-1M;未发现免疫品种.本研究发现中国辣椒种质的抗病性整体高于一年生辣椒,是重要的抗病种质来源,可用于象耳豆根结线虫抗病育种和后续抗病机理的研究.     

Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai–Tibetan Plateau

Carbon storage in the soils on the Qinghai–Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi‐household management pattern (MMP: grassland shared by several households without enclosures) and a single‐household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai–Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 Mg C/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31 × 10⁷ and 6.15 × 10⁷ Mg C/yr across the Qinghai–Tibetan Plateau relative to MMP, which more closely resembles pre‐1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai–Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai–Tibetan Plateau but also other grazing regions globally where such practices may exist.     

校园环境噪声监测与评价--以华中师范大学为例

环境噪声是环境质量评价的重要指标。通过噪声监测实验,记录了华中师范大学校园内的噪声污染数据,根据国家标准评估了校园环境噪声状况。试验采用网络剖分法,分别于昼间7:30~10:00和夜间22:00~22:55两个时间段对等效声级进行了测定。实验结果表明:昼间噪声污染更为严重,平均噪声超标率达到26%,夜间噪声污染相对较轻,但噪声超标率也达到19%。校园内不同功能区的噪声来源不同,工程施工产生的噪声是主要的污染源,影响比重达到58%。根据实验结果,校园声环境质量一般,需要对现状提出合理的改进建议。     

正交设计优化青蒿SRAP-PCR反应体系及引物筛选

为了建立青蒿的SRAP最佳扩增体系,并筛选出SRAP多态性引物,本研究以青蒿叶片DNA为模板,采用正交试验设计,以Mg^2+、dNTP Mix、Taq DNA聚合酶、引物和DNA模板5种因素5个水平,对青蒿SRAP反应体系进行研究。结果表明,青蒿SRAP-PCR最佳反应体系为:引物0.6μmol/L、Mg^2+2.0 mmol/L、模板DNA 5.1 ng、Taq DNA聚合酶2.0 U、dNTPs 0.25 mmol/L,总体积为25μL。各因素对扩增反应均有不同影响,其中引物浓度的影响最大,dNTPs的影响最小。运用该体系对不同种质资源的青蒿进行验证,证明该体系稳定可靠,并在30个引物组合中筛选出了25对扩增条带清晰,多态性丰富的引物组合。这一结论为今后利用SRAP标记技术进行青蒿分子遗传学研究提供了科学依据。     

优质国审棉品种——ZHM19

概述了ZHM19的选育过程、特征特性、产量、纤维品质和抗病性等特点及主要栽培技术措施。     

Cryptococcal osteomyelitis in a dog

Osteomyelitis caused by Cryptococcus neoformans was diagnosed in a three-year-old male Irish wolfhound. The case details and radiological findings of radiolucency and periosteal reaction of the left third metatarsal bone had lead to an initial diagnosis of a malignant bone tumour. Biopsy revealed a fungal granuloma and culture identified the causal organism. A four month course of ketaconazole was instigated and the lameness resolved. Twelve months after the end of treatment there was no recurrence of the problem.     

Antibody response to crustacean ectoparasites in rainbow trout, Oncorhynchus mykiss (Walbaum), immunized with Argulus foliaceus L. antigen extract

Abstract. A humoral antibody response was demonstrated by ELISA in rainbow trout immunized intraperitoneally with extracts from the branchiuran ectoparasite Argulus foliaceus. A similar immunization protocol produced a higher titre response in a rabbit. Both trout and rabbit identified several antigenic components on immunoblots. ELISA and immunoblotting indicated that rainbow trout and rabbit anti-A. foliaceus sera identified components from the parasitic copepods Lepeophtheirus salmonis and Caligus elongatus.     

Effects of dietary molybdenum on nematode and host during Haemonchus contortus infection in lambs.

The addition of molybdenum (0.05 mmol kg-1 dry-matter) to the diet of lambs given a trickle infection of Haemonchus contortus larvae (500 third stage larvae d-1 over six weeks) reduced mean faecal egg counts (epg) from 3952 to 2312 +/- 402 by 32 days (P less than 0.02) and greatly reduced the mean number of worms recovered from the abomasum 14 days after infection ceased (907 compared with 4167: P less than 0.01). Infection reduced haemoglobin concentrations less in lambs given molybdenum although the difference was small relative to the reduction in worm burden. Lambs not given molybdenum had low intraepithelial mast cell counts in the abomasal mucosa and less abomasal hypertrophy than expected from abomasal parasitism. Molybdenum did not consistently reduce the copper status of the host or the parasite. Previous exposure to molybdenum greatly reduced protein but not proteinase activity in, or secreted by, adult worms cultured for eight hours. It is suggested that molybdenum either increased the inflammatory response which preceded worm rejection or that it indirectly enhanced that reaction by reducing the effectiveness of copper-dependent, anti-inflammatory enzymes in the gastrointestinal mucosa.     

Evaluation of a monoclonal blocking ELISA and IHA for antibodies to Mycoplasma hyopneumoniae in SPF-pig herds.

A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) and an indirect haemagglutination assay (IHA) were applied to serum samples from 124 specific pathogen-free (SPF) breeding and multiplying herds, which participate in the routine serological surveillance of the Danish SPF programme. Clinical and pathological observations of the herds and microbiological culturing of Mycoplasma hyopneumoniae were used to calculate herd sensitivity, herd specificity and herd predictive values for the two serological assays. The ELISA was superior to the IHA in herd sensitivity and herd specificity, with values of 93 per cent and 96 per cent, respectively, for the ELISA, and 61 per cent and 92 per cent for the IHA. During the six month period of evaluation 2.5 per cent of the herds were infected with M hyopneumoniae each month. At this level the IHA was found to have a positive herd predictive value of 16 per cent, compared with 39 per cent for the ELISA. The negative herd-predictive value on the same level was 99.8 per cent for the ELISA and 98.9 per cent for the IHA. If the assays were applied to a group of herds with a herd prevalence of M hyopneumoniae infection of 30 per cent (as is the case with the production herds in the Danish SPF programme) the predictive value of a positive herd diagnosis would be 91 per cent for the ELISA and 76 per cent for the IHA, and the predictive value of a negative herd diagnosis would be 97 per cent with the ELISA and 85 per cent with the IHA.(ABSTRACT TRUNCATED AT 250 WORDS)