植物提取液对黄瓜白粉病的抑菌活性筛选研究

首先通过叶圆盘法用29种植物提取液对黄瓜白粉病菌的抑菌效果进行了生物活性测定,初步筛选出槐、黄檀、南瓜和石楠等4种植物的提取液对黄瓜白粉病有较好的预防效果。然后对这4种植物提取液进行预防性和治疗性的室内盆栽药效试验,结果表明黄檀提取液对黄瓜白粉病的预防效果达到72.97%,治疗效果达到91.28%,并且在处理12 d后仍保持42.60%以上的防效。而槐提取液的预防效果和治疗效果分别为79.73%和79.19%,处理12 d后也保持在50%以上的防效。这两种植物提取液均极显著优于对照药剂三唑酮。     

Number of Follicular Waves and Their Effect on Pregnancy Rate in the Cow

In the study, the relationship of follicular growth waves, oestradiol and pregnancy rates were investigated during oestrus cycle in cows. A total of 22, Brown Swiss cows (3-5 years old) were used for the study. The ovaries of animals were examined from sixth day of cycle to next oestrus by ultrasound. The follicles that were present in the ovarium were recorded. Follicular growth was observed every day by means of ultrasound examination. The blood samples were taken for analysis of oestradiol simultaneously with ultrasound examinations. The oestrus animals were inseminated. Each animal that inseminated was examined by ultrasound on day 28 after insemination for pregnancy diagnosis. Two follicular growth waves were observed in nine of 22 (40.9%), three waves in 13 of 22 (59.1%) animals. The oestradiol was found in the same concentration but in different release patterns between two and three waves animals. Pregnancy rate in cows with three and two follicular waves did not differ. In conclusion, emergence of three waves of follicular growth was higher in Brown Swiss cows, the analysis of oestradiol could be used for determination of the wave numbers and the animals with different waves may have had the same pregnancy rates.     

Modeling the Exchanges of Energy, Water, and Carbon Between Continents and the Atmosphere

Atmospheric general circulation models used for climate simulation and weather forecasting require the fluxes of radiation, heat, water vapor, and momentum across the land-atmosphere interface to be specified. These fluxes are calculated by submodels called land surface parameterizations. Over the last 20 years, these parameterizations have evolved from simple, unrealistic schemes into credible representations of the global soil-vegetation-atmosphere transfer system as advances in plant physiological and hydrological research, advances in satellite data interpretation, and the results of large-scale field experiments have been exploited. Some modern schemes incorporate biogeochemical and ecological knowledge and, when coupled with advanced climate and ocean models, will be capable of modeling the biological and physical responses of the Earth system to global change, for example, increasing atmospheric carbon dioxide.     

植物生长素在大果沙棘嫩枝扦插中的应用研究

在温室内对5个大果沙棘品种嫩枝用4种植物生长激素处理进行扦插育苗试验,结果表明,吲哚丁酸和生根粉处理效果显著,浑金和向阳两品种更容易扦插成活。     

“优标”水稻体系对稻田土壤环境的影响

【目的】 针对水稻生产中的减肥、减药措施,前期自主开发了水稻优标体系。本研究通过分析应用优标体系的稻米产量和污染物含量以及土壤质量,评估优标体系在实际农业生产中的应用效果,以期为该优标体系的合理设计和及时调整提供科学依据。【方法】 基于在江苏省、上海市水稻种植区连续实施1—5年的定点优标体系试验区,以常规施肥用药水稻栽培体系（简称常规体系）为对照。采集水稻籽粒和稻田土壤样品,测定稻米产量、委托SGS检测稻米农药残留和重金属含量;采用内梅罗指数法评价土壤肥力;分别采用TTC还原法、靛酚蓝比色法、3,5-二硝基水杨酸比色法测定土壤脱氢酶、脲酶、蔗糖酶活性;利用16S rDNA高通量测序分析土壤微生物多样性。【结果】 采用优标体系较常规体系在氮肥施用量减少46.8%,代以添加有机肥、EM菌剂、叶面肥、锌肥;以生物制剂为核心,协同使用低毒、低残留化学农药,保证了稻米的高安全标准。在保证水稻产量、质量安全的前提下实施优标体系显著提高了土壤全氮与有机质含量;且连续实施1—4年的优标体系土壤肥力综合评分均高于常规体系,但连续实施5年后的优标体系土壤肥力综合评分值低于常规体系。连续实施2年优标体系脲酶、脱氢酶、蔗糖酶的活性均高于常规体系。实施优标体系的稻田土壤细菌群落多样性与丰度提高,优标体系实施1年和连续实施5年的土壤细菌丰富度上升比例重复变化的菌为拟杆菌门（Bacteroidetes）和绿弯菌门（Chloroflexi）;优势菌属为Terrimonas（尚无确切名称）和黄杆菌属（Flavobacterium）。相关性分析结果显示,优标体系实施1年,土壤中拟杆菌门、绿弯菌门丰度变化分别与pH肥力指数、全磷肥力指数变化呈正相关;优标体系连续实施5年,土壤中拟杆菌门、绿弯菌门丰度变化均与pH肥力指数变化呈正相关。另外,拟杆菌门、绿弯菌门丰度变化与土壤脱氢酶活性变化呈正相关。【结论】 实施优标体系在保证水稻产量、质量安全的前提下,可有效改善土壤质量,提升土壤细菌群落多样性,进而有助于恢复土壤肥力。     

水分胁迫对水稻品种生理特性的影响

本实验以优质杂交粳稻滇型杂交水稻滇杂31为材料,采用盆栽实验,在水稻孕穗期设5个水分胁迫处理,进行了不同程度的水分胁迫,在水分胁迫结束后,对叶片光合特性、叶片与根系的丙二醛(MDA)浓度、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性的变化进行测定,研究水分胁迫对滇杂31孕穗期生理特性的影响。研究结果表明,孕穗期随着水分胁迫的加剧,滇杂31农艺性状、光合特性显著下降;叶片和根系的MDA浓度、POD活性、SOD活性都有所上升。     

传统梅园美感生成机制对当代梅花专类园设计的启示

梅花是中国传统园林喜用的主题植物之一。传统梅园所追求的赏梅意境是一种以传统文人的赏梅意趣为导向的、浪漫的梅园境界。传统文人所追求的"物我交融"的梅花审美取向在当代梅花专类园设计中仍然起到指导梅花种植和造景的作用。通过解析传统梅园美感生成机制,并以现代环境美学观点研究传统梅园的美感生成机制,指出梅园的环境美感是由感觉价值、形式价值和综合价值构成,并据此启发当代梅花专类园设计。     

Molecular detection of Chlamydophila abortus in post-abortion sheep at oestrus and subsequent lambing

Enzootic abortion of ewes (EAE), resulting from infection with the bacterium Chlamydophila abortus (C. abortus), is a major cause of lamb loss in Europe. The purpose of this study was to assess the potential impact of the shedding of organisms in post-abortion ewes at oestrus and subsequent lambing on the epidemiology of EAE. Using a newly developed C. abortus specific real-time PCR assay, few chlamydial genomes could be detected in vaginal swabs taken from post-abortion ewes at oestrus. At subsequent parturition, all ewes lambed normally with no macroscopic or microbiological evidence of infection. Real-time PCR analysis of placental samples identified very few or no chlamydial genomes, which contrasted significantly with samples taken at the time of abortion, where an average of 2.7x10(7) chlamydial genomes per microgram of total tissue DNA was detected. Few genomes could also be detected from vaginal and cervical tissue samples and lymph nodes taken post-mortem. The results, although not discounting the possibility of a chronic low level persistent infection in post-abortion ewes, suggest that the low levels of chlamydial DNA detected during the periovulation period and at lambing do not significantly impact on the epidemiology of EAE. In terms of flock management, the products of abortion should be considered the major and principal source of infection for transmission to na?ve ewes.     

基于“广义梯度理论”的乡村旅游发展途径分析

【目的】探索乡村旅游发展广义梯度推进途径,以促进乡村旅游的良性发展。【方法】通过对璧山县旅游资源、交通及企业发展等梯度要素的分析,获得璧山县乡村旅游发展的广义梯度结构,并提出其广义梯度推移途径。【结果】璧山县乡村旅游可以划分为3个梯度,一级梯度包括璧城乡村旅游组团,二级梯度包括璧北乡村旅游组团和璧南乡村旅游组团,三级梯度包括梅江河乡村旅游组团。【建议】优先开发高梯度旅游区,打造区域乡村旅游精品;有效实施广义梯度推移,延缓乡村旅游产品生命周期;加速广义梯度推移,实现乡村产业立体协调整合,以科学地推动璧山县乡村旅游发展。