丹参种子的萌发特性研究

通过研究光照、温度、pH值、赤霉素和覆土厚度等条件处理对丹参种子萌发的影响,探讨了丹参种子的萌发特性。结果表明,丹参种子最适宜的萌发温度为20~25℃,在适宜的温度下,全光照比无光照的发芽势和发芽率都高,对pH值的适宜范围比较宽,在pH值为2~10范围内均可萌发,赤霉素对丹参种子的萌发作用不明显,种子最适覆土厚度为1.0 cm,最适贮藏时间为6个月,生产中建议随采随播。     

施肥对水田和旱地有机碳和黑碳的影响

在30多年的长期肥料试验区, 研究了水田、旱地等2种利用方式下, 有机肥、化肥, 及有机肥和化肥混合施用对耕层土壤有机碳和黑碳质量分数的影响。结果表明:经过30多年稻Oryza sativa-稻-休闲耕作(水田), 早玉米Zea mays-晚玉米-冬闲制耕作(旱地)后, 无论水田、旱地氮磷钾化肥配施有机肥处理, 耕作层(0~20 cm)有机碳质量分数均高于单施化肥、不同化学肥料配施、单施有机肥以及不施肥, 说明相对于其他施肥处理, 有机无机肥配施为最佳施肥措施。黑碳质量分数红壤旱地集中在2.72~5.33 g·kg-1, 水田集中在9.01~10.60 g·kg-1, 旱地单施钾肥与单施有机肥处理, 氮与氮磷钾处理无显著差异, 其他各处理间黑碳质量分数差异显著(P < 0.05), 水田各处理黑碳质量分数差异不显著。旱地有机碳与黑碳显著相关(P < 0.05), 而水田有机碳黑碳相关不显著, 说明除施肥措施外, 土壤黑碳质量分数还可能受到土地利用方式、种植作物的影响。相同施肥措施下, 水田有机碳和黑碳质量分数均高于旱地, 说明水田更有利于有机碳、黑碳的累积。     

半蒴苣苔的叶片组织培养及植株再生

为了建立半蒴苣苔Hemiboea subcapitata的组培快繁技术体系,保护和开发利用半蒴苣苔这一民间植物药资源,以MS(Murashige and Skoog)为基本培养基,研究植物生长调节物质6-苄基腺嘌呤(6-BA)和萘乙酸(NAA)组合对叶片愈合组织诱导、不定芽分化,增殖和壮苗生根的影响,筛选出适合半蒴苣苔快繁的最适培养基。结果表明:叶片诱导愈合组织困难,但在叶片基部或切口处可直接诱导分化出不定芽,且随着6-BA 和NAA质量浓度的升高,芽的分化率先上升后降低,以MS+0.5 mg·L-1 6-BA+1.0 mg·L-1 NAA+1.5 g·L-1活性炭(AC)分化率最高,达到67.8%;但平均每外植体诱导芽数以MS+1.0 mg·L-1 6-BA +0.5 mg·L-1 NAA +1.5 g·L-1 AC最多,达到6.69个;不定芽增殖以MS+0.5 mg·L-1 6-BA+0.5 mg·L-1 NAA处理增殖倍数最高,达到23.43;在添加不同质量浓度吲哚丁酸(IBA)的培养基中生根率均超过90%。     

影响高粱茎秆汁液含量基因的精细定位

无论是用作牲畜饲料或榨汁做糖,茎秆汁液含量对于甜高粱而言都是一个非常重要的农艺性状。本研究通过对两套独立的F2群体观察统计发现,影响高粱茎秆汁液含量(MCS)的基因Dd呈现质量性状基因的遗传规律,且干髓对多汁为显性。用SSR标记初定位表明该基因位于第6号染色体,扩大定位群体后,用群体F2 1将其定位在标记sm06068和sm06093之间,用群体F2 2将其定位在sm06068和sm06069之间,两个区段的物理距离均约为470 kb。为了进一步缩小定位区间,对定位群体的亲本进行了测序分析并开发了2个InDel标记。最终,目标基因被锁定在只包含6个候选基因的区间范围内。基因d的精细定位为该基因的克隆及今后分子育种中的应用打下基础。     

In vitro Selection of DNA Aptamers and Fluorescence-Based Recognition for Rapid Detection Listeria monocytogenes

Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stranded DNA or RNA ligands containing random sequences of up to a few hundred nucleotides. Systematic evolution of ligands by exponential enrichment (SELEX) was used to select and PCR amplify DNA sequences (aptamers) capable of binding to and detecting Listeria monocytogenes, one of the major food-borne pathogens. A simplified affinity separation approach was employed, in which L. monocytogenes in exponential (log) phase of growth was used as the separation target. A fluorescently-labeled aptamer assay scheme was devised for detecting L. monocytogenes. This report described a novel approach to the detection of L. monocytogenes using DNA aptamers. Aptamers were developed by nine rounds of SELEX. A high affinity aptamer was successfully selected from the initial random DNA pool, and its secondary structure was also investigated. One of aptamers named e01 with the highest affinity was further tested in aptamer-peroxidase and aptamer-fluorescence staining protocols. This study has proved the principle that the whole-cell SELEX could be a promising technique to design aptamer-based molecular probes for dectection of pathogenic microorganisms without tedious isolation and purification of complex markers or targets.     

Soil Quality Assessment of Acid Sulfate Paddy Soils with Different Productivities in Guangdong Province,China

Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.     

La改性MCM-41在线催化提质生物油研究

选取油菜秸秆为试验原料,采用浸渍法对MCM-41分子筛进行不同负载量的La改性,利用La/MCM-41分子筛在两段式反应器上进行生物质真空热解在线催化提质制备生物油的试验研究。通过XRD、SEM、Py-IR等方法对MCM-41分子筛进行了表征分析,研究了金属La的引入对生物油有机相理化特性的影响。结果表明,经La改性后的MCM-41保持了载体高度有序的六方型结构,且La/MCM-41表面B酸和L酸的酸量进一步增强;La/MCM-41分子筛能有效降低生物油有机相中酸、醛、酮类等物质的含量,提高烃类物质的含量;当La负载量为5%时,生物油有机相产率增加到18.83%,p H值显著提高并趋向中性,有机相热值高达33.69 MJ/kg,有机相中烃类物质相对峰面积达到34.59%,且以单环芳香烃为主。     

病死动物源氨基酸研制的生物有机肥促生效果研究

废弃动物尸体酸解为氨基酸能够有效解决农业生产中动物尸体带来的环境污染问题,本研究利用此类病死动物资源水解的的氨基酸研制生物有机肥,以期在研制出低成本高品质生物有机肥的同时推进新型氨基酸的利用。本文首先比较了根际功能菌Bacillus amyloliquefaciens SQR9在添加不同浓度酸解氨基酸液有机肥中的固体发酵效果及不同浓度酸解氨基酸水解液发酵的生物有机肥盆栽促生效果,进而确立了生物有机肥的氨基酸添加浓度。再进一步通过黄瓜、辣椒和玉米盆栽试验,评估了所研制新型生物有机肥的促生效果。研究结果表明:酸解氨基酸水解液添加量为20%时,所研制生物有机肥中功能菌数量最高,达到2.25×10~8CFU/g,是未添加氨基酸对照的3倍。黄瓜盆栽促生试验表明,氨基酸添加量为20%所发酵的生物有机肥促生效果优于其他处理和对照,株高、茎粗、叶绿素、鲜重和干重值均为最高,根围土壤中功能菌的数量达2.51×10~5CFU/g。不同作物盆栽试验结果表明,添加氨基酸研制的含菌株SQR9生物有机肥处理的促生效果优于添加化肥研制的含菌株SQR9生物有机肥、有机肥直接接种菌株SQR9研制的生物有机肥、普通有机肥和添加氨基酸的普通有机肥处理,同时施用含SQR9菌株的肥料促生效果优于施用不含功能菌的相同配方制造的有机肥处理,表明,利用菌株SQR9研制的生物有机肥具有良好的促生效果,相比于化肥,添加氨基酸固体发酵功能菌后更加有益于功能菌促生功能的发挥。在各种作物根围土壤中的微生物涂布试验中,添加氨基酸研制的含菌株SQR9生物有机肥处理的功能微生物数量显著高于其他处理。综上,添加20%的氨基酸水解液能够有效促进功能微生物在有机肥中的繁殖,固体发酵形成的生物有机肥具有优异的促生效果。     

猪圆环病毒2型Taqman探针法实时荧光定量PCR检测方法的建立

猪圆环病毒2型（PCV2）是一种引起仔猪Sus scrofa多系统衰竭综合征、免疫抑制、皮肤肾病综合征等疾病的病原体。根据GenBank中PCV2 ORF1基因序列设计合成特异性引物和探针,以PCV2基因组DNA为模板,通过聚合酶链式反应（PCR）扩增目的片段,并将目的片段克隆至pMD18-T载体,构建阳性标准品。以阳性标准品为模板,优化荧光定量PCR反应条件,建立标准曲线,进行灵敏性、重复性和特异性验证,并应用此方法对临床样品进行检测。结果表明:阳性质粒标准品构建成功,该检测方法的引物与探针的最佳浓度皆为0.2 μmol·L-1,线性检测范围为2.1×1013~2.1×106拷贝·L-1,最低检测限值为8.828×106拷贝·L-1,且与其他相关疾病无交叉反应;各批次检测变异系数低,检测方法稳定性好。本研究建立的敏感性高、特异性好的实时荧光定量PCR方法,为PCV2的快速检测提供了新工具。     

气候变化对不同春小麦品种产量构成相关因素的影响

为进一步掌握近年来气候变化对东北春麦区小麦产量的影响,对4个不同类型春小麦品种连续6a产量、千粒重、穗粒数、容重及株高性状进行分析。结果表明:近年来气候变化主要体现在小麦生育期间降水分布不均,拔节期降水量对产量形成影响较大。同时气候的变化对穗粒数影响较大,可通过提高穗粒数才获得较高产量。