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51.
Prunus avium is primarily cultivated for its fruit, sweet cherries. However, it is also used to produce high‐quality timber. In a P. avium seed orchard, gametophytic self‐incompatibility is a restriction for free pollen flow and should be considered when establishing basic forest materials. In this study, S‐locus diversity and cross‐incompatibility of wild cherry individuals in clonal banks established for breeding for timber production were investigated. Wild cherry trees (140) with outstanding forest growth habit, collected in northern Spain, grafted and planted in two clonal banks, were genotyped at the S‐locus. The self‐incompatibility S‐locus genes, S‐RNase and SFB, were analysed by PCR. Twenty‐two S‐haplotypes, resulting in 72 different S‐genotypes, were identified. The genotypes were grouped into 33 incompatibility groups and 39 unique genotypes. This initial S‐locus analysis revealed large genetic diversity of wild cherry trees from the Spanish northern deciduous forest, and provides useful information for seed orchard design. Wild P. avium displays significantly more genetic diversity than what is detected in local cultivars, revealing a narrowing of genetic diversity during local domestication.  相似文献   
52.
以无籽刺梨组培苗根尖为材料,探讨其染色体制片技术。结果表明,无籽刺梨根尖在常温下用0.003mol/L8-羟基喹啉溶液预处理6-8h或0.004mol/L8-羟基喹啉溶液预处理4-6h后,在预冷的卡诺固定液(冰醋酸:无水乙醇=3:1中)0℃下处理15min,经95%乙醇:15% Hcl=1:1的解离液处理5min或无水乙醇:36-38% Hcl=1:1处理6min,然后用卡宝品红染色15或20min,其镜检效果较佳;无籽刺梨的染色体数目为2n=2x=14。无籽刺梨染色体制片技术研究及其染色体数目的确定对其遗传改良工作有着重要的意义。  相似文献   
53.
The study of interactions between minerals, organic matter (OM) and microorganisms is essential for the understanding of soil functions such as OM turnover. Here, we present an interdisciplinary approach using artificial soils to study the establishment of the microbial community and the formation of macro-aggregates as a function of the mineral composition by using artificial soils. The defined composition of a model system enables to directly relate the development of microbial communities and soil structure to the presence of specific constituents. Five different artificial soil compositions were produced with two types of clay minerals (illite, montmorillonite), metal oxides (ferrihydrite, boehmite) and charcoal incubated with sterile manure and a microbial community derived from a natural soil. We used the artificial soils to analyse the response of these model soil systems to additional sterile manure supply (after 562 days). The artificial soils were subjected to a prolonged incubation period of more than two years (842 days) in order to take temporally dynamic processes into account. In our model systems with varying mineralogy, we expected a changing microbial community composition and an effect on macro-aggregation after OM addition, as the input of fresh substrate will re-activate the artificial soils. The abundance and structure of 16S rRNA gene and internal transcribed spacer (ITS) fragments amplified from total community DNA were studied by quantitative real-time PCR (qPCR) and denaturing gradient gel electrophoresis (DGGE), respectively. The formation of macro-aggregates (>2 mm), the total organic carbon (OC) and nitrogen (N) contents, the OC and N contents in particle size fractions and the CO2 respiration were determined. The second manure input resulted in higher CO2 respiration rates, 16S rRNA gene and ITS copy numbers, indicating a stronger response of the microbial community in the matured soil-like system. The type of clay minerals was identified as the most important factor determining the composition of the bacterial communities established. The additional OM and longer incubation time led to a re-formation of macro-aggregates which was significantly higher when montmorillonite was present. Thus, the type of clay mineral was decisive for both microbial community composition as well as macro-aggregation, whereas the addition of other components had a minor effect. Even though different bacterial communities were established depending on the artificial soil composition, the amount and quality of the OM did not show significant differences supporting the concept of functional redundancy.  相似文献   
54.
李分龙  陈庆富 《安徽农业科学》2011,(17):10135-10138
[目的]探索一种适合荞麦的简单易行的染色体原位PCR技术。[方法]采用16S套式引物、4.5S套式引物与psbA引物,以栽培甜荞为材料,进行染色体原位PCR、原位套式PCR与多次原位PCR试验。[结果]高温干燥可以起到与包埋类似的作用;染色体的原位套式PCR效果比原位PCR明显,多次原位PCR次数为5-6效果较佳。16S引物和4.5S引物均显示了4对信号,但位置不同;而psbA引物是单拷贝的,仅显示出1对信号。根据这些信号的位置差异可以区分普通荞麦的5对染色体。[结论]所使用的荞麦染色体原位PCR技术简单易行。  相似文献   
55.
试验旨在鉴定吉林省某雏鸡孵育基地病死雏鸡组织中分离出的1株致病性菌CCGGD201101株并测定其致病性。对疑似致病菌进行生理生化试验、16S rDNA测序鉴定,并人工接种昆明鼠,测定其半数致死量,验证细菌毒力。经鉴定该菌为鲍曼不动杆菌(Acinetobacter baumannii)。以鲍曼不动杆菌CCGGD201101分离株为研究对象,并以鲍曼不动杆菌标准株(ATCC 19606)为对照,测得半数致死量,进一步证明鲍曼不动杆菌病死鸡分离株CCGGD201101具有较强致病性。  相似文献   
56.
本文设计了基于RFID技术的一种刷卡式的充电服务终端硬件装置,实现刷卡自动计费。本程序以AT89S52单片机为主控制器,用MFRC500射频识别芯片进行识别,并与射频卡进行通信。  相似文献   
57.
利用纤维素琼脂选择培养基和刚果红染色方法,从不同来源的土样中分离出2个菌株,测定了其纤维素酶活性、小麦秸秆降解能力,并对纤维素降解能力强的两个菌株进行了分子鉴定。结果表明,两株高效纤维素分解菌在纤维素刚果红培养基上均能形成透明水解圈,利用16S r RNA序列测序并分析Genbank中的同源性,结合形态和理化性质确定为Bacillus thuringiensis和Bacillus anthracis。在37℃,p H为7的条件下测定了纤维素酶活力,SC1-3和XR2-5-4分别为1.41和1.59。这两株37℃下经15 d后小麦秸秆失重率达19.92%和22.83%。  相似文献   
58.
The sesame crop is highly susceptible to infection by phytoplasmas, a class of cell wall-less plant pathogenic bacteria (Mollicutes), which is responsible for widespread loss of sesame crops in both North and South India in recent years. Therefore, characterizing the pathogen population is required before the control measures can be devised and implemented. With molecular tools based on nested polymerase chain reaction (PCR) assays, sequencing, restriction profiling, and phylogenetic analysis, phyllody-affected sesame plants collected from nine different states of India were found to be infected by phytoplasmas belonging to two 16Sr groups, namely 16SrI and II. Two subgroups of phytoplasma −16SrI-B and 16SrII-D— were prevalent in symptomatic sesame samples collected from North India, whereas phytoplasma of only the 16SrII group was found in South India. However, the latter samples were diverse, belonging to three different subgroups (16SrII-A, II-C, and II-D). In addition, yearly phyllody-affected sesame samples from Delhi for 4 consecutive years (2007–2010) showed variation in the infecting phytoplasma: the subgroup 16SrII-D was detected in samples collected in 2007, and 16SrI-B was predominantly found in the samples collected in the subsequent years. The study also provides molecular evidence for the association between 16SrI-B phytoplasma and different symptoms in sesame crops such as fasciation, little leaf, and stunting. This is the first study to report the association of the phytoplasma subgroups 16SrII-A and II-D with sesame crops in India. This study provides a baseline for designing specific detection and molecular analysis strategies for quarantine purposes. It also highlights the need for examining the dynamics of seasonal or location-specific variation in vector populations to determine the pattern of infection outbreaks.  相似文献   
59.
介绍了6S管理的内涵、实施方案,以及引入6S管理的必要性与可行性。针对当地个体食品生产者生产馒头的现状,引入6S管理体系,取得了良好的效果。  相似文献   
60.
基于对高校实验室科学化、网络化管理的目的,采用查阅大量相关文献资料,分析国内外研究现状,进行系统设计、实现,并通过实践验证研究效果的技术路线,构建了基于B/S结构模式的高校实验室信息管理系统。通过在河北农业大学基础化学实验室的具体应用,达到了实验室无纸化办公、高效率管理的效果。  相似文献   
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