油萝卜抗胞囊线虫基因的染色体定位及其在油菜附加系中的稳定性

【目的】油萝卜（2n=18,9条染色体分别被称作a～i）具有抗甜菜胞囊线虫的基因。探索油萝卜携带的抗甜菜胞囊线虫基因所在的染色体和外源的油萝卜染色体在油菜中的遗传稳定性。【方法】9个油菜附加系进行自花受粉,分别获得附加系的自交F2代。利用筛选的分子标记检测和原位杂交（FISH）检测附加染色体在F2代中的遗传稳定性;通过对9个油菜附加系F2代接种甜菜胞囊线虫的2龄幼虫,鉴定携带抗甜菜胞囊线虫基因所在的染色体。【结果】9个附加系自交F2代中的附加染色体遗传表现不一,5个油菜附加系的F2代中均有2条附加染色体,能稳定遗传;4个附加系的自交后代中附加染色体的遗传表现不稳定,部分后代中无附加染色体。FISH检测9个附加系自交F2代中的附加染色体表明：与分子标记检测的结果相符,并且4个不稳定的附加系中,有的自交后代虽然有附加染色体,但有1或2条。接种甜菜胞囊线虫测定结果表明,含有油萝卜染色体DD的油菜附加系对甜菜胞囊线虫的抗性水平与附加染色体的供体油萝卜相当,而其它8个附加系的自交后代未表现出抗性,与受体油菜相近。【结论】油萝卜的9条染色体分别附加到油菜中后,其遗传稳定性因附加的染色体而异,有的能稳定遗传,有的在自交后代中丢失1或2条;抗甜菜胞囊线虫的基因在d染色体上。     

齐口裂腹鱼幼鱼对蛋白质、脂肪和碳水化合物需要量研究

试验设21个日粮组, 蛋白质、脂肪、碳水化合物梯度变化范围分别在33% ~ 51%、3% ~ 18%、23% ~ 32%。在水温( 25. 25 ? 1. 91) e 条件下, 在水泥池中对平均体重为( 2. 01 ? 0. 04) g的360尾齐口裂腹鱼进行了60 d的生长试验, 研究日粮中蛋白质、脂肪和碳水化合物对齐口裂腹鱼生长、体组成和肝脏组织的影响。结果表明: 各组鱼特定生长率随着日粮蛋白质水平的增加而增加; 体蛋白含量不受日粮组成的影响, 体脂肪随着日粮脂肪水平的增加而增加, 体碳水化合物受日粮碳水化合物的影响极显著, 而不受日粮蛋白质和脂肪的影响。齐口裂腹鱼幼鱼能耐忍23% ~ 26%的碳水化合物水平, 且能利用6% ~ 12%的日粮脂肪。基于齐口裂腹鱼幼鱼对日粮碳水化合物和脂肪含量需求分别为23% ~ 26%和6% ~ 12%时, 蛋白质需求量为42% ~ 48%, 能蛋比为41. 3 kJ/g。     

Antimicrobial sensitivity testing of Australian isolates of Bordetella avium and the Bordetella avium-like organism

SUMMARY: The in-vitro sensitivity of 16 Australian isolates of Bordetella avium and 15 isolates of B avium -like organism to 11 antimicrobial agents or combinations of agents was determined using a microtitre plate system to establish minimal inhibitory concentrations. All the B avium isolates were sensitive to ampicillin but resistant to erythromycin, lincomycin, spectinomycin, sulphamethoxazole, trimethoprim, and lincomycin + spectinomycin. Most of the B avium isolates were sensitive to tetracycline and resistant to streptomycin and sulphadiazine. All the B avium -like isolates were resistant to ampicillin, erythromycin, lincomycin, spectinomycin, streptomycin, tetracycline, trimethoprim, and lincomycin + spectinomycin. Most B avium -like isolates were sensitive to sulphadiazine, sulphamethoxazole and trimethoprim-sulphamethoxazole.     

习近平同志关于向海经济的重要论述与实践研究

南海是金枪鱼类的重要分布区,开展南海金枪鱼类养殖潜在适宜区选划研究具有重要意义。南海金枪鱼类的主要种类为黄鳍金枪鱼 (Thunnus albacares) 和鲣 (Katsuwonus pelamis),根据其物种出现点以及7种南海环境数据,采用最大熵 (Maximum Entropy, MaxEnt) 模型定量评估了南海黄鳍金枪鱼和鲣的潜在养殖适宜性指数。结果表明：1) 模型受试者工作特征曲线的下面值均大于0.848,表明模型准确度良好,可用于模拟金枪鱼类养殖潜在适宜区的分布;2) 表层溶解氧、表层水温、底层水温、底层盐度是影响南海黄鳍金枪鱼和鲣养殖适宜栖息地分布的重要环境因子。其中,黄鳍金枪鱼的最适宜范围为：表层溶解氧浓度201.52~242.68 mol·m⁻³、底层水温1.96~32.61 ℃、底层盐度34.37‰~35.26‰;鲣的最适宜范围为：表层溶解氧浓度200.83~208.35 mol·m⁻³、表层水温19.71~28.96 ℃、底层盐度34.30‰~35.26‰;3) 黄鳍金枪鱼和鲣的养殖潜在高适宜分布区域较为集中,黄鳍金枪鱼主要集中在东沙渔场、南沙中部渔场以及南沙中西部渔场的东北部,鲣主要集中在台湾南部渔场的中西部以及东沙渔场。

     

Effect of Geogenic Lead on Fungal and Collembolan Communities in Garden Topsoil

Geogenic lead (Pb) is considered to be less bioavailable than anthropogenic Pb and exerts less effect on the soil fauna. However, Pb contamination in vegetables has been reported in the case of geogenic anomalies, even at moderate concentrations (around 170 mg kg^–1). In this study, we investigated collembolan communities using both taxonomic- and trait-based approaches and observed fungal communities to assess the effects of a moderate geogenic Pb anomaly on collembolans and fungi in an urban vegetable garden soil. Results indicated that geogenic Pb indeed modified fungi communities and altered the functional structure of collembolan communities in garden soils. Although geogenic Pb presented low bioavailability, it affected soil fauna and vegetables similar to anthropogenic Pb.     

多媒体技术在《动物微生物》教学中的应用

多媒体技术在现代教学中应用广泛,成效也日益显著,在《动物微生物》教学中应用多媒体技术进行教学,既可丰富学生的理论知识,又能促进学生动手能力的提高。     

The effect of immunosuppression on protective immunity of turkey poults against infection with turkey coronavirus

The objective of the present study was to evaluate the protective effect of humoral and cellular immunities on turkeys infected with turkey coronavirus (TCV). Two trials were conducted with two separate hatches of turkey poults. Turkey's were experimentally immunosuppressed with cyclosporin A (CsA) or cyclophosphamide (CY) and infected with TCV. Prior to infection, treatment with CsA selectively suppressed T cell activity as revealed by 2-3 fold decreased (p < 0.1) lymphocyte proliferation responses to a T cell mitogen, concanavalin A (Con A). Treatment with CY mainly induced B cell deficiency as indicated by significant reductions (p < 0.05) in antibody responses to sheep erythrocytes 7 days after injection. Body weight gain of turkeys treated with CY was significantly lower (p < 0.05) than that of untreated turkeys at 9 days post-infection (PI). Turkeys treated with CY had 1-2 fold higher immunofluorescent antibody assay (IFA) scores for TCV antigens (p < 0.05) in the intestine than untreated turkeys at 9 or 14 days PI. These results suggested that humoral immunity against TCV infection may be important in turkeys.     

STABILIZATION OF DUNE SAND AT BORGO BONSIGNORE IN SICILY / STABILISASIE VAN DUINSAND BY BORGO BONSIGNORE IN SICILIE

The methods employed and the results achieved in stabilizing an area of about 225 ha dune sand is described. The techniques employed in allowing tree species to become established are mentioned and are illustrated by various plates     

保持系稻株对孕穗期干旱胁迫伤害与补水修复的育性响应

以负压式土壤湿度计和取土烘干法双重监控盆栽试验的土壤水势变化,观测我国14个常用水稻保持系的孕穗期耐旱性,并以干旱胁迫指数人为划分钝感、耐旱、不耐旱与敏感4个等级,其中K22-B、金23-B为孕穗期干旱胁迫钝感材料,珍汕97-B、中9-B为孕穗期干旱胁迫敏感材料,比较研究它们对干旱胁迫伤害的育性响应与补水修复的特征。结果表明,钝感或敏感保持系稻株主穗耐旱性均强于分蘖穗,粒位间强势粒耐旱性均高于弱势粒。这一生物学现象似"植物顶端优势"的逆境生理学表现。比较孕穗期中花粉母细胞减数分裂期、花粉粒形成期与花粉粒充实期的耐旱性,花粉粒充实期耐旱性最弱,花粉母细胞减数分裂期耐旱性较强。孕穗期干旱后补水对结实伤害的恢复效果明显,尤其对耐旱性强的保持系稻株修复更明显,主要途径是降低秕谷率而不降低空壳率,表明干旱胁迫育性损伤是不可逆的。