β-1,3-葡聚糖及其羧甲基衍生物对海湾扇贝免疫功能的影响

2003年3月和2004年4月，新疆某养殖场和西安灞桥区某养殖场的白斑狗鱼（Esox lucius Linnaeus）相继爆发“败血症”。从具有明显症状的濒死病鱼体表病灶和内脏组织分离得到12株优势菌株，经人工感染试验表明：其中10株分离菌为致病菌。对分离菌株进行形态、培养特征、生理生化试验鉴定，认为该病原菌为杀鲑气单胞菌史氏亚种（Aeromonas salmonida subsp．smith）。血清学试验表明各分离菌株具有相同的保护性抗原。组织病理学研究表明：患病狗鱼病灶肌纤维明显肿胀断裂，肌纤维束之间出现间隙；肝胰组织严重坏死，细胞核溶解消失，细胞浆崩解；肾小管绝大部分均已坏死，细胞破裂，胞浆呈红色团块状流失于管腔。脾脏细胞大量坏死，髓质内含铁血黄素沉积。代表菌株EL0304-1药敏试验结果为：对供试24种抗菌药物中的磺胺二甲嘧啶钠、磺胺二甲嚯唑钠等不敏感；庆大霉素、卡那霉素等中度敏感；对氧氟沙星、培氟沙星、新霉素等高度敏感。     

Detection of quinolone-resistance genes in Photobacterium damselae subsp. piscicida strains by targeting-induced local lesions in genomes

Quinolone-resistant strains of the fish-pathogenic bacterium, Photobacterium damselae subsp. piscicida are distributed widely in cultured yellowtail, Seriola quinqueradiata (Temminck & Schlegel), in Japan. The quinolone resistance-determining region (QRDR) was amplified with degenerate primers, followed by cassette ligation-mediated PCR. Open reading frames encoding proteins of 875 and 755 amino acid residues were detected in the gyrA and parC genes, respectively. Resistant strains of P. damselae subsp. piscicida carried a point mutation only in the gyrA QRDR leading to a Ser-to-Ile substitution at residue position 83. No amino acid alterations were discovered in the ParC sequence. A mutation in the gyrA gene was also detected in nalidixic acid-resistant mutants of strain SP96002 obtained from agar medium containing increased levels of quinolone. These results suggest that GyrA, as in other Gram-negative bacteria, is a target of quinolone in P. damselae subsp. piscicida. Furthermore, we attempted to detect a point mutation using targeting-induced local lesions in genomes (TILLING), which is a general strategy used for the detection of a variety of induced point mutations and naturally occurring polymorphisms. We developed a new detection method for the rapid and large-scale identification of quinolone-resistant strains of P. damselae subsp. piscicida using TILLING.     

马链球菌马亚种新疆株ZX表面蛋白的提取及免疫原性分析

为研究马链球菌马亚种新疆分离株 ZX 表面蛋白的免疫原性,用化学法提取该菌的表面蛋白,用 SDSG PAGE检测提取的表面蛋白,并将提取的表面蛋白与该菌免疫实验兔后产生的抗体及康复马血清反应,利用 WestG ernGblotting和 ELISA试验分析其免疫原性.结果表明,SDSGPAGE电泳可检测到分子量为45,34,33,30,27,20,16 kDa 7条主蛋白带.提取的7条蛋白带多数可与全菌免疫兔的抗体及康复马体内的抗体发生特异性的结合.用提取蛋白和全菌包被 ELISA对马血清的检测表明,二者的阳性吻合率在86．0％.表明提取的表面蛋白具有理想的免疫原性.     

尾叶拉藤多糖含量测定

本文采用苯酚-硫酸比色法,测定尾叶拉藤中多糖的含量。结果表明尾叶拉藤中多糖含量为3.85%,平均加样回收率101.38%。     

凹叶厚朴叶的生长规律与开发利用

凹叶厚朴既是传统的药用植物，又是具备保健功能的食品资源。本文观察研究了凹叶厚朴叶的物修、生长规律、生物量、化学成分和浓缩汗的工艺小试，为可持续利用植物资源提供参考。     

Identification of somatic hybrids of dihaploid Solanum tuberosum lines and S. brevidens by species specific RAPD patterns and assessment of disease resistance of the hybrids

Summary Symmetric somatic hybrids were produced by electrofusion of protoplasts of two dihaploid tuber-bearing potato (Solanum tuberosum L.) lines and Solanum brevidens Phil., a diploid non-tuber-bearing wild potato species. A total of 985 plants was obtained. Verification of nuclear hybridity of putative hybrids was based on additive RAPD patterns, general morphological characteristics and chromosome counts. 53 (90%) calli regenerated into plants which were identified as somatic hybrids. Most of the hybrids were aneuploids at the tetraploid (4×) or hexaploid (6×) level. The 20 hybrids tested expressed a high level of resistance to potato virus Y (PVY ^N ) characteristic of the S. brevidens parent. Resistance to late blight (Phytophthora infestans (Mont.) de Bary) varied between hybrids, but was on average better than that of the fusion parents. Resistance of hybrids to bacterial stem rot (Erwinia carotovora subsp. atroseptica (van Hall) Dye) was not superior to that of commercial potato cultivars.     

Resistance to Rhopalosiphum padi (Homoptera: Aphididae) in Hordeum vulgare subsp. spontaneum and in hybrids with H. vulgare subsp. vulgare

Summary Accessions of Hordeum vulgare subsp. spontaneum, the progenitor of cultivated barley, were screened in field and glasshouse trials for resistance to the aphid Rhopalosiphum padi. A few selected lines were furthermore hybridized with a modern barley variety and the resulting populations evaluated. High levels of resistance were found among some of the spontaneum accessions resulting in lower aphid growth rates (maximum reduction 57%). Segregation patterns among siblings in F2 populations were continuous, indicating the presence of several genes with possibly additive effects. The usefulness of H. vulgare subsp. spontaneum for breeding aphid resistant barley is discussed.     

Genetics of resistance to five strains of turnip mosaic virus in Chinese cabbage

Summary Inheritance of resistance to turnip mosaic virus (TuMV) strains C1, C2, C3, C4, and C5 in Chinese cabbage (Brassica campestris subsp. pekinensis) was evaluated using monoclonal antibodies. Crosses were made between a resistant line, 0–2, and four susceptible line. Seoul (SE),SSD31 (SS), Cheongbang (CH), and Yaki 1 ho (YA), to determine the inheritance of resistance of 0–2 in different genetic backgrounds. Resistance to TuMV was controlled by a single dominant gene or double dominant genes depending on the strain and cross. The resistance genes of 0–2 were modified by susceptible parents such that a single dominant gene was involved in the SS×0–2 combination, but double dominant genes in the SE×0–2 against TuMV-C3 or TuMV-C5. ELISA tests using inoculated and noninoculated leaves in the same plant suggested that the dominant resistance genes inhibit virus movement rather than virus multiplication.     

Chromosomal interchanges and phylogeny of some accessions of Triticum aestivum subsp. spelta

Summary The occurrence of chromosomal interchanges was studied in F1 hyrids in two diallel schemes, including nine accessions of Triticum aestivum subsp. spelta, originating from Iran, Europe and North Africa, and the common wheat variety Chinese Spring as a reference. Seven accessions of subsp. spelta differed in one translocation from Chinese Spring. The European accession Grey differed in one or perhaps two interchanges from the reference variety, and Iran 417a showed a difference of three interchanges with Chinese Spring. In total six or perhaps seven interchanges were observed. Thus the number of translocation events in subsp. spelta appeared to be low. One translocation was unique and occurred only in the accession from North Africa. Also one accession from Europe, the landrace Schwarzwald, possibly carried a unique translocation. In both diallels an interchange with a relatively low coefficient of multivalent realisation at first meiotic metaphase was observed in most accessions. The two extra translocations in Iran 417a are considered to be the result of more recent translocation events, whereas the possible second translocation in accession Grey showed such a low coefficient of multivalent realisation that its existence could be doubted.     

木糖氧化无色杆菌反硝化亚种细菌的分离鉴定及其菲降解特性研究

利用选择性富集培养及升华法,从石油污染的土壤中分离到2株菲降解细菌,它们在以菲为唯一碳源的培养基上生长良好。应用BIOLOG细菌鉴定系统和分子生物学方法对两株细菌进行鉴定,两株菌分别为坚强芽孢杆菌(Bacillus.firmus)和木糖氧化无色杆菌反硝化亚种(Achromobacter.xylosoxidanssub.sp.denitrificans),两株菌均具有邻苯二酚氧化酶活性。两株细菌在液体培养条件下都表现较强降解菲的能力,液体培养60.h约90%的加入菲被降解。通过测定液体培养基中菲浓度和菌体密度变化发现,菌株降解菲的量与其生长密度相关;随着菌体浓度(吸光度)的增加,代谢底物菲的浓度明显降低,两株菌混合使用能够大幅度提高降解菲的能力。