萘乙酸对大白菜钙素吸收运转及防治干烧心病的研究

本研究从补钙入手,探索防治干烧心病的方法。用0.7％CaCl_2·2H_2O对和50ppmNAA混合液在大白菜结球期叶面喷洒5次,经8年试验,对大白菜干烧心病的相对防治效果达80％以上。 在此基础上,采用~(45)Ca示踪试验的方法对防病机理做了进一步研究。结果表明,无论从根部还是从叶部加萘乙酸对根部和叶部~(45)Ca的吸收和运转均具有促进作用,并且改变了其在大白菜植株内的分配规律。对照株单位干叶重dpm值自外向内呈下降趋势(130×10~3─60×10~3);用NAA处理株则相反,自外向内呈增加趋势(120×10~3─250×10~3),说明萘乙酸具有促进钙素向叶球中内部运转的功效。这种效果在贮藏期间仍能保持。另外,~(45)Ca向直接受到NAA处理部位的运转量有明显增高的趋势。这一结果为补钙防治干烧心病提供了理论依据。     

普通番茄与秘鲁番茄杂种后代的形态,亲和性及抗性表现

继获得普通番茄‘北京早红’与秘鲁番茄杂交种后,本试验着重于对杂种后代的形态、亲和性及抗性表现的观察,杂种的多数性状为双亲中的显性性状或双亲的中间型,但也表现了一些奇异性状,如果实的颜色和花序的形状与排列通过株间的“杂交”克服了杂种的高度自交不亲和性,从而顺利得到杂种的自交后代;杂种各世代均高抗TMV 0株系和1株系,并有部分选系抗TMV 1·2株系,由此判断秘鲁番茄亲本可能具有TM~a_2基因;用南京地区CMV厥叶株系和强株系分别接种,各世代表现部分抗病或耐病。     

Detection and characterization of leptospiral antigens using a biotin/avidin double-antibody sandwich enzyme-linked immunosorbent assay and immunoblot.

A biotin/avidin double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of antigens of Leptospira interrogans serovars in experimentally inoculated bovine urine samples was evaluated. Immunoglobulin G (IgG) from rabbits immunized with L. interrogans serovar hardjo type hardjobovis sonicated, whole cell, and formalinized-heated antigen preparations were purified by a protein A-superose column coupled to fast protein liquid chromatography, and evaluated for species specificity in the ELISA. The ELISA using each specific IgG detected as few as 10(4) leptospires of the homologous serovar hardjo diluted in phosphate-buffered saline solution with Tween 20 (PBSS-Tween 20). On immunoblot analysis of proteinase-K-digested whole cell leptospiral preparations, each IgG revealed the presence of bands specific to serovar hardjo, suggesting the presence of serovar-specific epitopes on the lipopolysaccharide molecules. The minimum number of cells of heterologous serovars pomona, grippotyphosa, bratislava, icterohaemorrhagiae and copenhageni detected by each ELISA was greater, ranging from 10(6) to 10(7). The common antigenic determinants observed on immunoblot analysis were different for each specific IgG, except for a major cross-reacting, possibly flagellar, protein doublet at approximately 36-36.5 kDa. Leptospires were equally well detected by the ELISA in both bovine urine and PBSS-Tween 20.     

Characterization of and radioimmunoassay for canine thyroglobulin

Canine thyroglobulin (cTg) has been isolated and purified. It has similar electrophoretic patterns as Tg from other mammalian species. The main fraction had a MW of 660,000, whereas also fractions of a MW of approximately 1,300,000 (dimer) and 330,000 (subunit) were present. The iodine content was 0.8 to 1.0 % (w/w). cTg did not cross-react with antibodies against human Tg to a degree that would allow the use of a radioimmunoassay for human Tg for the determination of cTg in serum or plasma. Therefore a polyclonal antiserum was raised against cTg and a homologous radioimmunoassay was developed, which was sensitive (0.4 μg/l) and specific (cross-reactivity in cTg assay of human Tg, goat Tg, T₄, T₃, and DIT < 0.01 %).

Plasma Tg levels in normal dogs of both sexes and aged 3–15 years amounted to 192 ± 73 μg/l (mean ± SD, n=30). There was no relation between plasma Tg and T₄ levels.     

汝城白毛茶种群个体间亲缘关系的RAPD分析

采用RAPD技术,对汝城白毛茶种群个体间的亲缘关系进行了分析。研究结果:汝城白毛茶种群个体单株扩增的谱带数最多时为13条,最少时为10条;DNA多态性最高为92.31%,最低为70.00%,平均为85.40%。结果表明汝城白毛茶种群呈现丰富的遗传多样性。汝城白毛茶种群单株间的遗传距离最小为0.0882,最大为0.5791。聚类分析结果表明汝城白毛茶种群中有些单株聚类很近,遗传基础比较一致,有些聚类较远,显示其丰富的遗传多样性。研究发现种群单株间的遗传变异呈现连续性,当结合距离I为0.14时,汝城白毛茶种群可分为6个类型,这与其表观形态类型相符。本文运用分子生物学方法证明汝城白毛茶的核心种质基因群在汝城县白毛茶示范场得到了有效保护。     

Construction and Development of the Dagangshan Forest Ecosystem Research Station

Established by the former Ministry of Forestry in 1986, Dagangshan Forest Ecosystem Research Station is one of the 14 national key sites in the field of ecosystem research. In this paper, the basic situation of Dagangshan Forest Ecosystem Station is described, including geographic location, natural conditions, biological resources, research conditions, instruments, achievement, prospects etc.     

山洪对房屋的破坏及防患

山洪对房屋的破坏随着生态环境的恶化而加剧,其损失又随人民生活水平的提高而增加。防患房屋遭受山洪破坏刻不容缓。本文客观地总结了山洪破坏房屋具有的区域性、多样性、毁灭性特征,通过分析房屋遭受山洪破坏的沉痼陋习,初步揭示了山洪惩罚人为性大失误的沉痛教训,进而提出防患山洪破坏房屋要非工程措施与工程措施相结合,运用社会、经济、法律的手段,加以减灾引导,加强建房管理,采取开撇水沟、挖水平槽、刨鱼鳞坑、砌护坡墙、打挡水桩等直接有效的工程措施,加速隐患补救,实现减灾目的。     

Environmental source of mycobacteriosis in a California swine herd.

Between July 1985 and April 1986, mycobacterial lymphadenitis was recorded in six of 2407 slaughter pigs from a commercial swine herd in which the majority of pigs were raised in confinement. Records showed that all six affected pigs had access to dirt-floored pens at least 81 days prior to slaughter. The mycobacteriosis lesion rate for pigs exposed to dirt pens was 9.4% while in nonexposed pigs the lesion rate was zero. The risk associated with movement of pigs from concrete floored pens to dirt pens was evaluated by a field trial. In the field trial, two litters (5 of 15 pigs) exposed to dirt pens at 12-24 days of age but none of nine nonexposed litters (39 pigs) developed lesions. Mycobacterium avium-complex bacteria were recovered from both exposed litters (9 of 15 pigs) but from none of nine nonexposed litters. Serovars of M. avium-complex isolated from trial pigs included 1, 4, 8, 9, the dual serovar 4/8, and an untypable serovar. Incense-cedar bark (Calocedrus decurrens) used as a flooring material in the pens was demonstrated to be a potential source of M. avium-complex serovar 9. The dual serovar 4/8 and an untypable M. avium-complex were isolated from the dirt-floored pens. No evidence of cross-transmission of M. avium-complex infection was detected. The sporadic pattern of mycobacteriosis observed in the herd probably resulted from infrequent exposure to a common environmental source.     

抗绵羊进行性肺炎病毒单克隆抗体杂交瘤细胞株的建立

用提纯的OPPV细胞抗原免疫BALB/c小鼠脾脏与SP2/0小鼠骨髓细胞融合,融合率为70%,以ELISA双抗体夹心法进行检测,阳性率为20%,经过有限稀释法克隆出1A₆、2B₈、1G₃、2G₄4株分泌抗OPPV抗原的单克隆体杂交瘤细胞株.选择抗体分泌滴度高的1A₆细胞进行了较详细的研究,结果表明,其核内染色体数为96～110条,抗体属性为IgG1,轻链为K链,IFA试验表明产生的McAb对OPPV有特异性,细胞传30代并在液氮中保存半年后复苏仍能稳定地分泌抗OPPV McAb,细胞分泌抗体的ELISA滴度腹水为6.4×10⁴,上清为640,McAb经硫基乙醇还原后在SDS-PAG上呈现2条区带,一条为重链部分,MW50000,另一条为轻链部分,MW为25000.     

苹果果皮细胞膜结构变化与虎皮病的关系

国光苹果在贮藏过程中,果皮内α—法尼烯不断积累,60天左右达最大值,后随共轭三烯的迅速增加而下降。与此同时,果皮中丙二醛积累,组织相对电导率增加。抗氧化剂二苯胺能显著降低果皮中丙二醛积累,阻止相对电导率的上升,减少发病率。对膜结构变化与虎皮病的关系进行了讨论。