土壤中碳酸盐的碳氧同位素分析

本文采用磷酸法分析土壤中碳酸盐的碳、氧同位素组成,对分析方法和制样装置作了叙述,比较了经不同预处理土壤的碳、氧同位素值,指出土壤有机碳的存在不影响碳酸盐同位素组成的精密测定,有氧灼烧预处理土壤样品对分析结果有明显影响,使δ~13C和δ~18O值降低。测定多种标准样品表明,此方法准确、可靠,重复制样测定的标准偏差在0.1‰以内。     

Sr18菌代谢产物对线虫应激能力的影响

基于Sr18菌代谢产物在24 h内具有显著的杀线虫活性,为进一步探究其杀线虫机理和作用规律,测定其在16 h内对线虫应激能力的影响。结果表明,在4 h时处理组对外界条件刺激的敏感性明显提高,运动频率均高于对照组,表明4 h为Sr18菌代谢产物对线虫产生作用的转折点;8 h后处理组活跃程度明显减弱,对刺激的反应较对照组缓慢,随着刺激时间增加,处理组的活跃性有所增加但不显著,表明Sr18菌代谢产物已产生明显的药效作用,致使线虫对刺激反应迟钝。Sr18菌代谢产物对线虫应激能力的影响呈现"平稳-上升-下降"的规律,进一步探究Sr18菌代谢产物的作用机理为实践中的合理用药提供理论依据。     

亚麻新品种"双亚18号"的选育

双亚18号是选用高纤、高产品系93-318为母本,以法国高纤、抗倒伏品种Diane为父本进行杂交,经混合系谱法选择育成的纤维亚麻品种.生产试验的原茎、全麻和种子产量分别为6040.6、1 575.8和629.5 kg/hm2,分别比对照品种增产15.6％、26.8％和12.3％.该品种具有高纤、优质、抗旱的特点,抗病和耐盐碱性较强,全麻率31.6％,比对照高2.6个百分点,纤维强度251N.     

3株塔克拉玛干沙漠藻的分子鉴定与分析

以从新疆塔克拉玛干沙漠中分离纯化的3株藻种为研究对象,研究温度和不同培养基对这3个品系生长的影响,并采用扫描电镜图和光学显微镜结合的方法对其形态进行初步鉴定,进一步采用18S r DNA基因数据对其进行分子鉴定。结果可以看出,Y1在20~30℃环境中都能生长,30℃生长最佳,最佳培养基为BG11培养基;Y2和Y3在改良型TAP培养基中生长最佳,它们的最适生长温度分别为25~30℃和30℃。利用Gen Bank中绿藻门不同科属种类序列的18S核糖体RNA,结合Olmos的文献,设计18S r DNA特异性引物进行PCR扩增。测序后经Blast对比、系统发育树及遗传距离分析,结合扫描电镜图和光学显微镜结果得知Y1为丝藻属、Y2为衣藻、Y3为绿球藻。     

驯鹿18S rRNA基因的克隆测序

对驯鹿 (Rangifertarandus)的 1 8SrRNA基因片段进行了克隆测序 ,序列长度为 1 1 47bp ,并且已被发送到Genebank上 ,其登录号是AY1 45 5 2 7。     

Study on some molecular characterization of Babesia orientalis

The study on buffalo babesiosis indicated that its pathogen was different from other Babesia on many aspects such as morphology, transmission and pathogenicity. Therefore, it was named as a new species—Babesia orientalis. In order to prove the validity of this taxon, molecular taxonomic study on the pathogen was done in this experiment. The complete 18S rRNA gene sequence of B. orientalis was determined by PCR. It was sequenced and blasted. The results indicated that the classification of the parasite belonged to the genus Babesia. The 1700 bp complete sequence was compared with 15 other Babesia sp. available in GenBank. The data were analyzed and a phylogenetic tree was established. The results indicated that the hereditary distance of the parasite was close to that of Babesia sp. from South Africa and Babesia ovis, and the hereditary distance was far from Babesia bigemina and B. bovis.     

Prolonged elevated atmospheric CO2 does not affect decomposition of plant material

Prolonged elevated atmospheric CO₂ might alter decomposition. In a 90-day incubation study, we determined the long-term (9 years) impact of elevated CO₂ on N mineralization of Lolium perenne and Trifolium repens plant material grown at ambient and elevated CO₂ and low- and high-¹⁵N fertilizer additions. No significant differences were observed in recovery rates between any of the treatments, except an N addition effect was observed for L. perenne (0.4 versus 0.5% day⁻¹ in high versus low N). The results suggest that elevated CO₂ did not change plant N mineralization in any of the soils, because of a surplus of available N in the fertilized and leguminous systems, and because of insignificant plant responses to elevated CO₂ in the low soil N availability systems.     

Molecular characterization and diagnostics of stubby root and virus vector nematodes of the family Trichodoridae (Nematoda: Triplonchida) using ribosomal RNA genes

Plant parasitic nematodes of the family Trichodoridae cause substantial yield losses in many agricultural crops. Rapid and accurate identification of trichodorids to the species level is critical for selection of appropriate measures for control. This study analysed 99 sequences of the D2–D3 expansion segments of the 28S rRNA gene and 131 sequences of the 18S rRNA gene from the stubby nematodes belonging to the genera Nanidorus, Paratrichodorus and Trichodorus. Species delimiting was based on the integration of morphological identification, which is not provided in the present article, and molecular‐based phylogenetic inference and sequence analysis. Twenty‐two valid species and several species complexes were identified among nematodes included in the analysis. PCR‐RFLPs of the partial 18S rDNA and the D2–D3 expansion segments of the 28S rDNA were tested and proposed for identification of these nematodes. Gel PCR‐RFLP profiles and tables with restriction fragment lengths for several diagnostic enzymes are provided for identification. Some problems of taxonomy and phylogeny of nematodes of the family Trichodoridae are also discussed.     

犬巴贝西虫病PCR检测方法的建立

为快速、准确检测犬巴贝西虫病,根据GenBank中收录的犬的巴贝西虫18sRNA基因序列,设计合成1对特异性诊断引物,建立了PCR诊断方法。结果扩增出了犬巴贝西虫18sRNA基因的一段大小为319bp片段,经测序,所扩增序列与报道的序列完全匹配。同时对附红细胞体、巴氏杆菌DNA样品进行扩增没有出现扩增条带。阳性犬全血DNA稀释1 000倍后,依然可以有效地检测出虫体DNA。结果表明,所建立的PCR检测方法,具有极高的敏感性和特异性,可以运用于临床检测巴贝西虫病。     

高产优质油菜新品种淮油18号的选育

淮油18号是江苏徐淮地区淮阴农科所选育的甘蓝型优质油菜新品种,2010年9月通过江苏省农作物品种审定委员会审定。该品种株型紧凑、角果直生、结角层整齐、熟期一致,具有高产、优质、病害轻、适合机械收获等特点。主要适宜江苏省及周边省份油菜主产区推广种植。