串叶松香草营养价值及应用研究进展

本文在前人研究的基础上,对串叶松香草的营养价值、利用方法和推广前景进行了综述,为该优良牧草未来大力推广和科学利用提供依据。     

杂交晚稻新组合比较试验

2005年引进10个杂交晚稻新组合在我县晚稻区进行比较试验，结果表明，谷优734、金两优18、谷优9482丰产性、抗逆性、适应性、农艺性状表现优良，2006年可扩大示范；Ⅱ优8216、T优353多数性状表现较好，建议2006年续试；其余组合多数性状表现差，中止试验。     

Identification of a chitinase-producing bacterium C4 and histopathologic study on locusts

In order to develop the potential of chitinase-producing micro-organisms as biocontrol agents for insect pests, five chitinase-producing bacterial strains (C1, C2, C3, C4 and C5) previously isolated from soil samples were chosen to infect grassland locusts. The data showed that the mortality rate of locusts fed with strain C4 was significantly higher than that of other groups, and its pathogenicity was confirmed by Koch's law. Midgut tissues of locusts infected with C4 were examined with a light microscope. Apparent histopathologic changes in midgut cells partly explained the pathogenesis of locusts. Therefore, strain C4 was considered to be a potential biocontrol agent. To determine the taxonomic position of C4, physiological and biochemical characteristics were determined and molecular identification was performed. The 16S rDNA gene of C4 was amplified, cloned and sequenced. Comparative sequence analysis demonstrated that C4 corresponded to the genera Sanguibacter, Oerskovia and Cellulomonas. On the basis of phenotypic characterization and sequence similarity analysis, strain C4 was more closely related to the genus Sanguibacter. This chitinase-producing strain C4, which closely corresponds to the species of the genus Sanguibacter and is pathogenic to locusts, is here reported for the first time.     

杨树伐根嫁接法造林技术研究初报

选择成熟树木意大利214杨的伐根作砧木,欧美107杨和荷兰3930杨作接穗,依据细胞再生原理,进行插皮法嫁接。该法造林可解决杨树主伐更新换代问题和低产林改造问题。通过砧木处理、削接穗、插接穗、稳固接口、培土和田间管理等技术措施,寻求杨树速生丰产的办法,挖掘增加森林资源的潜力,提早发挥森林的三大效益。试验结果显示:该法造林具有投资省、适应性强、成活率高、抗逆性强、生长量大、效益高等特点,达到了预计的目标,收到了良好的效果。     

甘肃省自然资源持续利用战略定量研究

资源问题是区域可持续发展的核心问题。其开发利用过程是一个涉及自然、经济和社会的复杂过程。本文以可持续发展理论为指导 ,运用系统分析方法 ( AHP方法 )对甘肃省自然资源持续利用战略进行定量研究 ,并得出如下结论 :生态环境是自然资源持续利用的前提 ;对资源的合理利用应坚持寓保护于开发的方针 ;加强政府宏观调控是资源得以持续利用的保证 ;加强区际协作是甘肃省域可持续发展的必要条件。     

强壮水螅（Hydra robusta）和水丝蚓（Limnodrilus sp.）对七种洗衣粉毒性的反应

本文用七种洗衣粉分别对强壮水螅（Hydra robusta）和水丝蚓（Limnodrilus sp.)进行了毒理实验。结果表明：一定浓度的洗衣粉能影响水螅和水丝蚓的正常生命活动，并可造成它们的大量死亡。48h对强壮水螅所测得的七种洗衣粉的半致死浓度（LC50）：WB、AM、LB、QS、QQ、TZ、HL-28分别是：33.50、35.16、55.54、28.44、33.38和27.54mg/L；水丝蚓的半致死浓度（LC50）分别为:82.41、64.86、89.13、82.22、98.17、60.26和102.33mg/L。     

Cross-sectional study of the seroprevalence to Borrelia burgdorferi sensu lato and granulocytic Ehrlichia spp. and demographic, clinical and tick-exposure factors in Swedish horses

A cross-sectional study of the seroprevalence to Borrelia burgdorferi sensu lato and granulocytic Ehrlichia spp. in Swedish horses was conducted to evaluate associations with demographic, clinical and tick-exposure factors. From September 1997–1998, blood samples from 2018 horses were collected from the animals presented to veterinary clinics affiliated with the Swedish Horserace Totalizator Board (regardless of the primary cause for consultation). Standardized questionnaires with information both from owners and attending veterinarians accompanied each blood sample. The apparent seroprevalences to B. burgdorferi s. l. and granulocytic Ehrlichia spp. were 16.8 and 16.7%, respectively. The northern region had the lowest seroprevalences. Four logistic models were developed (controlling for demographic variables). In the disease model of seropositivity to B. burgdorferi s. l., age, breed, geographic region, the serologic titer to granulocytic Ehrlichia spp., season and the diagnosis coffin-joint arthritis were significant. In the tick-exposure model of B. burgdorferi s. l., pasture access the previous year and gender were significant. Age, racing activity, geographic region, season and the serologic titer to B. burgdorferi s. l. were associated with positivity to granulocytic Ehrlichia spp. In the tick-exposure model of granulocytic Ehrlichia spp., pasture access was a risk factor. An interaction between racing activity and geographic region showed that the risk of positive serologic reactions to Ehrlichia spp. was increased in the horse population in the south and middle of Sweden, but only among horses not used for racing. Except for the positive association between coffin-joint arthritis and serologic reactions to B. burgdorferi s. l., there were no significant associations in the multivariable models between non-specific or specific clinical sign or disease with seropositivity to either of these agents.     

Risk factors for Marek's disease and mortality in white Leghorns in Norway

A prospective longitudinal field study was conducted in the period from January 1994 to January 1996 to analyse the relationship between some selected risk factors in the growing and laying periods and (1) the flock-level occurrence of Marek’s disease (MD) during the period from 16 to 32 weeks of age and (2) the cumulative mortality during the same period. A total of 171 layer flocks in 102 egg-production farms were included in the statistical analyses.

A logistic regression (with strain of layer and vaccination program against MD as fixed effects) of flock-level MD-status during the first 16 weeks of the laying period was conducted. Of the risk factors investigated, “multi-age management” and “housing system” were significantly associated at the rearing farm, and “number of hens in each cage” at the egg-production farm. Flocks kept in single-age facilities had a lower risk of MD than flocks housed in farms with multi-age management. The odds of MD were larger for flocks housed on a litter floor in the rearing farms compared to flocks housed in battery cages. At the egg-production stage, flocks kept in battery cages housing more than three hens were at greater risk of MD than those held in cages for three hens or less.

A weighted least-squares regression (with strain of layer and flock-level MD-status as fixed effects) of cumulative mortality during the period from 16 to 32 weeks of age was also run. The same risk factors (with the same directions of effects) and “size of the rearing farm” were included in the final model of mortality. Chicks reared in medium-sized farms were at higher risk of dying than those coming from either small or large rearing farms. Our results confirm the importance of preventing chicks from being exposed to MD-virus during the rearing period, to reduce the risk of MD-outbreaks (and thereby, mortality losses) during the early stage of the egg-laying period.     

波尔山羊胚胎移植研究报告

该研究受体羊（杂交奶山羊）１８４只,供体波尔母羊７６只。通过同期发情处理,７６只羊共排卵７２６个,其中受精卵３８７,占据排卵总数的５３．３１％。在受精卵中,有效胚３５３个,其中一级胚３１２个,二组胚４１个。共移植１８４只受体羊,基本正常产羔的受体母羊１０５只,占移植受体羊总数的５７．０７％。在受体母羊中,９７只移植２个胚胎,有５５只产双羔,占９７只受体羊的５６．７％。成活羔羊１５０只,其中公羊７８只,母羊７２只。公母羊平均出生重３．０５千克,最大出生重５．５千克。     

不同水稻种子包衣剂比较试验

通过 3个不同来源的水稻种衣剂进行试验分析 ,结果表明 :合肥丰乐农化厂的种衣剂对种子发芽率、水稻生育期没有影响 ,对秧苗素质有明显的促进作用 ,对苗期稻瘟病具有较高的抗性 ,且有明显的增产效果 ,小区产量显著优于两对照种衣剂处理