调亏灌溉和氮处理对小桐子生长及水分利用的影响

为了研究阶段水分亏缺(亏水+不亏水W_LW_H、不亏水+亏水W_HW_L、亏水+亏水W_LW_L、不亏水+不亏水W_HW_H)和不同施氮量(N_Z:0,N_L:0.2 g/kg,N_H:0.4 g/kg)对小桐子生长、生理指标和灌溉水利用效率的影响,通过盆栽试验,发现W_LW_H的生长和灌溉水利用效率均显著高于W_HW_L;作物的灌溉水利用效率随施氮量的增大而呈现先增大后减小的趋势,在N_L水平下达到最大值;与高水高氮的处理N_HW_HW_H相比,中水低氮处理N_LW_LW_H节约灌溉水27%,节约氮肥使用量50%,小桐子株高减少31%、总干物质量减少35%,灌溉水利用效率减少13%,但茎粗增加13%,根冠比增加20%.可见小桐子在第一阶段处理(40~90 d)幼树期对水分的需求量较小,适度的亏缺灌溉可提高灌溉水利用效率;小桐子在第二阶段处理(90~140 d)处于旺长期,对水分的需求量较大,增大灌水量可大幅度促进小桐子生长及其干物质量的积累.全生育期实施亏缺灌溉,可提高小桐子自身适应外界环境能力,抗干旱胁迫能力也逐渐增强,但W_LW_L水平下的小桐子生长缓慢.经综合分析,认为处理N_LW_LW_H可作为干旱地区条件下的小桐子灌溉和施氮制度.     

柞蚕蛹血淋巴多酚氧化酶活性影响因素的研究

柞蚕血淋巴中多酚氧化酶活性的大小对柞蚕丝产量有一定影响,并对柞蚕蛹色起着非常重要的作用。本试验采用分光光度计法对柞蚕蛹血淋巴多酚氧化酶活性大小的影响因素进行了研究。结果表明:柞蚕蛹血淋巴多酚氧化酶的最适pH值为5.0;最适温度为25℃;少量的苯基硫脲对其的抑制作用较为明显;不同化合物对多酚氧化酶的活性影响不同,在相同浓度下,氯化钙和氯化镁对柞蚕蛹血淋巴多酚氧化酶的活性有促进作用,其他化合物(EDTA,维生素C和亚硫酸钠等)则表现为抑制作用。     

埋植抗原缓释剂ARD后牛乳特异性抗体效价评价

对奶牛埋植抗原缓释剂ARD(antigen release devise)生产免疫乳的高效性进行评价,随机选择40头成年健康荷斯坦奶牛,试验组20头奶牛于右侧髋内淋巴结处埋植3种释放时间不同的ARD,分别在埋植当天、14 d和28 d释放抗原,通过ELISA检测血清和乳清中特异性抗体的效价及消长规律。研究表明:埋植ARD免疫后,奶牛血清中特异性抗体滴定效价均明显升高,ELISA滴定效价平均为2×106。埋植后9 d便可检测到乳清中特异性抗体,其应答规律与3种ARD的释放一致,ELISA滴定效价平均可以达到4.1×104,可以达到2~3 d初乳的水平。试验结果说明了ARD生产免疫乳的高效性;通过比较血清和乳清中特异性抗体含量变化,发现在血清效价相同的情况下,奶牛个体对IgG的转运存在差异;ARD的缓释技术较为精确,缓释误差仅为2~3 d。     

沈阳农业大学配电网优化方案

本文在大量调查统计数据的基础上，对沈阳农业大学这一综合性配电网进行了各种测算与分析，提出了切实可行的改造措施及长远设想，同时，进行了经济效益分析。     

黄淮海稻区水稻品种的穗颈瘟抗性

[目的]为明确黄淮海稻区育成水稻品种的稻瘟病抗性及其基因型,[方法]收集了来自本稻区5个不同地区的水稻品种,连续两年通过稻瘟病菌接种鉴定和田间病圃自然诱发对供试品种进行了稻瘟病抗性鉴定,并利用4个抗病基因Pita, Pib, Pi54和Pikm的分子标记,对水稻品种基因型进行了统计分析,并以抗性等级为表型值对品种资源进行聚类分析。[结果]黄淮海稻区水稻品种发病率较高,分别达 85.2%和 65.9%。Pi54和Pib检出率分别达 84%、65%。同时抗性聚类分析表明Pi54和Pib在本稻区的抗性贡献率却很低。[结论]黄淮海稻区水稻品种稻瘟病抗性弱,携带的抗瘟基因的抗性在不断减弱或丧失,需加强稻瘟病主效抗性的发掘、开发与利用。     

一组木质纤维素分解菌复合系的筛选及培养条件对分解活性的影响

以麦秸垛下的土壤和麦秸堆肥为材料 ,利用限制性培养技术 ,经过多代淘汰及其不同系之间的组配 ,最终筛选构建了一组木质纤维素分解菌复合系。用羧甲基纤维素 (CMC)糖化力法和纤维素减重法研究了不同培养条件对复合系分解纤维素能力的影响。结果表明 ,以滤纸、棉花、稻草、CMC Na和葡萄糖为碳源时 ,复合系在天然纤维素含量高的碳源 (如滤纸、棉花 )存在时表现出高的纤维素分解活性 ;利用蛋白胨和酵母粉作氮源时的纤维素分解活性远高于硝酸铵、尿素等无机氮源 ;以滤纸和酵母粉作为惟一碳、氮源时 ,最适发酵质量浓度分别为 2 5和10 0 g·L-1,其分解活性最高峰均出现在发酵第 5天。最适纤维素分解的 pH为 8 0。最适纤维素分解温度为 6 0℃ ,大于 6 0℃的高温抑制复合系对纤维素分解 ;复合系的适宜溶氧量 (DO)为 0 0 7～ 0 16mg·L-1,过高过低的溶氧量均抑制纤维素分解。复合系的微好氧特点对堆肥工程降低生产成本具有重要意义。     

Establishment of Chinese soybean Glycine max core collections with agronomic traits and SSR markers

It is very important to efficiently study and use genetic diversity resources in crop breeding and sustainable agriculture. In this study, different sampling methods and sample sizes were compared in order to optimize the strategies for building a rationally sized core collection of Chinese soybean (Glycine max). The diversity in the core collection captured more than 70% of that in the pre-core collection, no matter what sampling methods were used, at a sampling proportion of 1%. Core collections established with both simple sequence repeat (SSR) marker data and agronomic traits were more representative than those chosen on an independent basis. An optimal sampling method for a soybean core collection was determined, in which strategy ‘S’ (allocating accessions to clusters according to the proportion of square root of the original sample size within each ecotype) was used based on SSR and agronomic data. Curve estimation was used to estimate the allelic richness of the entire Chinese soybean germplasm and a minimum sample size for a core collection, on which a sampling proportion of about 2% was determined to be optimal for a core collection. Further analysis on the core collection with fourteen agronomic traits and allelic constitution at 60 SSR loci suggested that it highly represented the entire collections both on genetic structure and diversity distribution. This core collection would provide an effective platform in proper exploitation of soybean germplasm resources for the study of complex traits and discovering important novel traits for crop genetic development.     

基于GF-1影像面向对象分类方法的水稻种植信息提取研究

应用遥感技术提取水稻种植信息是农业遥感的重要内容。GF-1卫星WFV数据为农业信息提取提供了新的途径,面向对象的分类方法是遥感解译的重要方法。本研究以扬州市为研究区域,基于GF-1影像WFV数据,采用面向对象的分类方法,提取水稻种植信息,并实地调查验证试验结果,试图探讨GF-1数据面向对象分类方法在水稻种植信息提取中的可行性与影响提取精度的因素。结果表明,应用GF-1数据,采用面向对象的分类方法能够很好地完成扬州市水稻种植信息的提取,2016年扬州市有水稻种植面积214 524 hm~2,总体精度达到98.5%,Kappa系数0.95,面积精度达97.5%;实地考察能够提高提取精度,地形破碎程度越低,提取精度越高。     

Effects of six years of simulated N deposition on gross soil N transformation rates in an old-growth temperate forest

Elevated atmospheric nitrogen(N) deposition has been detected in many regions of China, but its effects on soil N transformation in temperate forest ecosystems are not well known. We therefore simulated N deposition with four levels of N addition rate(N0, N30, N60, and N120) for6 years in an old-growth temperate forest in Xiaoxing'an Mountains in Northeastern China. We measured gross N transformation rates in the laboratory using ~(15)N tracing technology to explore the effects of N deposition on soil gross N transformations taking advantage of N deposition soils. No significant differences in gross soil N transformation rates were observed after 6 years of N deposition with various levels of N addition rate. For all N deposition soils, the gross NH_4~+ immobilization rates were consistently lower than the gross N mineralization rates,leading to net N mineralization. Nitrate(NO_3~-) was primarily produced via oxidation of NH_4~+(i.e., autotrophic nitrification), whereas oxidation of organic N(i.e., heterotrophic nitrification) was negligible. Differences between the quantity of ammonia-oxidizing bacteria and ammonia-oxidizing archaea were not significant for any treatment, which likely explains the lack of a significant effect on gross nitrification rates. Gross nitrification rates were much higher than the total NO_3~- consumption rates,resulting in a build-up of NO_3~-, which highlights the high risk of N losses via NO_3~- leaching or gaseous N emissions from soils. This response is opposite that of typical N-limited temperate forests suffering from N deposition,suggesting that the investigated old-growth temperate forest ecosystem is likely to approach N saturation.     

温室立体式茶树育苗机的设计

针对传统茶树温室育苗架存在的占地多、劳动强度大及生产率低等问题,设计了一种立体式茶树育苗机。该机可一次性培育茶树苗4608株,转速控制范围为0.01~0.1r/min,可满足茶树苗不同生长阶段对光照时间的需求。其使用不仅提高了茶树育苗的自动化水平,而且相比于传统温室育苗,设施育苗的面积利用率提高到208.96%,成苗率提高了7.85%。