丘陵区湿地松林昆虫群落结构的初步研究

在湖南省株洲市郊区,对10块湿地松林样地的昆虫群落结构进行调查研究表明,这些林分内计有昆虫12目87科103种,马尾松毛虫和微红梢斑螟是优势种。林内昆虫群落结构简单,大多处于不稳定状态,自控能力较差。在适宜的气候条件下,马尾松毛虫种群有迅速增殖、暴发成灾的可能。针对这种情况,提出了封山育林、营造混交林等促进其昆虫群落稳定的综合管理措施。     

湖南省马尾松毛虫灾害与松林林分状况的关系

马尾松毛虫灾害与松林林分状况关系密切,松阔混交林、国外松占40%以上松林和植被覆盖度达90%以上的松林一般不发生松毛虫灾害。松林蓄积量越大,松毛虫发生面积越小。     

层卧孔菌深层培养的研究

本文研究了层卧孔菌[Fomitiporia punctata(Fr.)Murr.]的菌种分离、培养基配方.探索了培养条件,并投入中试规模的批量生产.层卧孔菌最适培养基为麦麸-蔗糖-酵母粉.中试生产温度控制在28±2℃,最适pH为5.5～6.0,最佳接种量为15%～20%.通气量为1:0.5(v/■v/min).培养80h左右.即可得到层卧孔菌菌丝体培养物.     

草鱼对点状气单胞菌和柱状屈桡杆菌二联菌苗的免疫反应

将酚灭活的点状气单胞菌和柱状屈桡杆菌菌苗按不同比例制备成二联菌苗，注射接种草鱼后，通过检测受免草鱼血清中的凝集抗体效价和攻毒试验，初步证明了由这两种菌制备的酚灭活菌苗，可刺激草鱼产生良好的免疫反应，免疫保护力达到５６．０％～７３．０％。     

New interspecific rice genome constructions obtained by symmetric cell fusion

Newly released rice varieties are mostly progenies of common commercial cultivars and so most gene sources for rice breeding have closely related genotypes. Protoplast fusion technique is a method that can produce hybrid plants in one‐step within a desired cultivar. To introduce new genetic diversity into rice‐breeding materials, hybrids between Oryza sativa L. (AA) and Oryza punctata Kotschy ex Steud. (BBCC) were generated by symmetric protoplast fusion. The genomic distribution in interspecific somatic hybrids was investigated by multi‐colour genomic in situ hybridization. Differences in chromosome numbers were observed not only between different somatic hybrid plants but also within individual hybrid plants. Chromosomal reduction of the A genome was found in two somatic hybrids. These results suggest that it is possible to reconstruct new interspecific rice genomes. Chromosomal reduction in interspecific somatic hybrids may be used to generate breeding lines with novel chromosomal constitutions.     

金鱼致病菌的分离鉴定与药敏特性

采用常规方法对患病金鱼(Carassius auratus)内脏组织(肝脏、肾脏、性腺)中致病菌进行了分离鉴定与药敏特性研究。结果显示:实验共分离了8株优势菌,经人工回归感染实验证实其中3株细菌(菌株LK-T、PL-R和PK-T)具有致病性。ATB细菌鉴定仪鉴定结果显示,菌株LK-T和菌株PL-R为温和气单胞菌(Aeromonas so-bria),菌株PK-T为豚鼠气单胞菌(Aeromonas punctata subsp.caviae)。这3株致病菌的主要特征为:革兰氏染色阴性,杆状,对奈替米星、头孢呋肟、头孢拉啶、庆大霉素、环丙沙星、新霉素、先锋必等药物均高度敏感。其中庆大霉素、环丙沙星、新霉素等常规渔药可作为防治用药的依据。     

肠型点状气单胞菌口服疫苗微粒的制备及体外释放研究

采用复乳溶剂挥发法,以聚丙烯酸树脂Ⅲ为材料制备肠型点状产气单胞菌疫苗微球,进行了条件优化.研究结果显示,制备得到的口服疫苗微粒形态良好,平均粒径(6.78±0.07)μm,载药量和包封率分别为(6.04±0.07)%和(63.52±0.06)%,19 d时的累积体外释放百分率为65%.复乳溶剂挥发法置备的肠型点状产气单胞菌疫苗微球工艺可行,重复性良好,有一定的缓释特性.