检索结果-南通市图书馆

Isolation and Partial Characterization of a Novel Pollen-specific cDNA with Multiple Polyadenylation Sites from Wheat

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第7期36卷 467-476页

作者： Yong-Feng JIN* and Teng-Fei BIANInstitute of Biochemistry, zhejiang university, hangzhou 310029, china Institute of Biochemistry Zhejiang University Hangzhou 310029 Chin

A novel pollen-specific full-length cDNA clone PSG076 was isolated using suppression subtractive hybridization and 5’/3’ RACE techniques. PSG076 was shown to exhibit multi-site polyadenylation by sequencing the 3’ ends of the cDNAs. At least six transcripts with different length were produced from the single gene based on different poly(A) tail attachment sites. However, polyadenylation consensus sequence AAUAAA was not seen at the 3’-untranslated sequence. PSG076 contained a 299 bp 5’ untranslated region and an open reading frame of 663 bp encoding a 221 amino acid peptide with pI of 4.31. A blast search revealed that this sequence did not show a significant similarity to any genes deposited in the public database. Southern blot indicated that PSG076 was a single copy gene. Northern blot and RT-PCR analysis indicated that PSG076 transcripts showed specific expression in mature pollen, and weak or undetectable signals in uninucleate microspore, immature seed, stem, young leave, root and ovary. Further analysis of the expression pattern in gametophyte showed that PSG076 transcripts were undetectable in uninucleate, binucleate microspore and pollen at early stage, and were first detectable and increased rapidly at middle and late stages of pollen development with the maximum level in mature pollen and also expressed in germinating pollen in vivo, suggesting that PSG076might play a role in pollen germination and pollen tube growthin addition to its function in maturation. The evidences gathered in this work indicated that the six different transcripts from the single gene were differentially expressed during pollen development.

关键词： wheat (Triticum aestivum L.) pollen-specific cDNA suppression subtractive hybridization multiple-site polyadenylation differential expression

Plant MITEs: Useful Tools for Plant Genetics and Genomics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2003年第2期1卷 90-100页

作者： Ying FengAgriculture and Biotechnology College, zhejiang university, hangzhou 310029, china Agriculture and Biotechnology College Zhejiang University Hangzhou 310029 China

MTTEs (Miniature inverted-repeat transposabie elements) are reminiscence ot non-autonomous DNA (class Ⅱ) elements, which are distinguished from other transposable elements by their small size, short terminal inverted repeats (TIRs), high copy numbers, genie preference, and DNA sequence identity among family members. Although MITEs were first discovered in plants and still actively reshaping genomes, they have been isolated from a wide range of eukaryotic organisms. MITEs can be divided into Tourist-like, Stowaway-like, and pogo-like groups, according to similarities of their TIRs and TSDs (target site duplications). In despite of several models to explain the origin and amplification of MITEs, their mechanisms of transposition and accumulation in eukaryotic genomes remain poorly understood owing to insufficient experimental data. The unique properties of MITEs have been exploited as useful genetic tools for plant genome analysis. Utilization of MITEs as effective and informative genomic markers and potential application of MITEs in plants systematic, phylogenetic, and genetic studies are discussed.

关键词： miniature inverted-repeat transposable element MITE transposable element retrotransposon evolution plant

Accumulation of Pathogenesis-related Type-5 Like Proteins in Phytoplasma-infected Garland Chrysanthemum Chrysanthemum coronarium

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第11期36卷 773-779页

作者： Bo-Xiong ZHONG and Yan-Wei SHENDepartment of Bioresource Science, College of Animal Science, zhejiang university, hangzhou 310029, china Department of Bioresource Science College of Animal Science Zhejiang University Hangzhou 310029 Chin

Soluble proteins extracted from leaves, apical shoots, axillary shoots, and stems of garland chrysanthemum plants infected by onion yellows phytoplasma were analyzed by two-dimensional gel electrophoresis. Computerized matching analysis revealed that at least six soluble proteins were accumulated specifically in phytoplasma-infected garland chrysanthemum. N-terminal amino acids sequences of these soluble

关键词： phytoplasma garland chrysanthemum Chrysanthemum coronarium pathogenesis-related proteins thaumatin osmotin

Knowledge-Based Classification in Automated Soil Mapping

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2003年第3期13卷 209-218页

作者： ZHOU BIN and WANG RENCHAOInstitute of Agricultural Remote Sensing and Information Technology Application, zhejiang university, hangzhou 310029 (china) Institute of Agricultural Remote Sensing and Information Technology Application Zhejiang UniversityHangzhou 310029 China

A machine-learning approach was developed for automated building of knowledgebases for soil resources mapping by using a classification tree to generate knowledge from trainingdata. With this method, building a knowledge base for automated soil mapping was easier than usingthe conventional knowledge acquisition approach. The knowledge base built by classification tree wasused by the knowledge classifier to perform the soil type classification of Longyou County,zhejiang Province, china using Landsat TM bi-temporal images and CIS data. To evaluate theperformance of the resultant knowledge bases, the classification results were compared to existingsoil map based on a field survey. The accuracy assessment and analysis of the resultant soil mapssuggested that the knowledge bases built by the machine-learning method was of good quality formapping distribution model of soil classes over the study area.

关键词： classification classification tree knowledge-based rule extracting soilmapping

Physico-Chemical Properties and Laboratory Hyperspectral Reflectance of Coastal Saline Soil in Shangyu City of zhejiang Province, china

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2003年第3期13卷 193-198页

作者： SHI ZHOU, HUANG MINGXIANG and LI YANInstitute of Agricultural Remote Sensing and Information System, zhejiang university, hangzhou 310029 (china) Institute of Agricultural Remote Sensing and Information System Zhejiang University Hangzhou 310029 China

4. and 50 composite soil samples were collected, respectively, from twoagricultural fields, that were enclosed and reclaimed from coastal tidal-flat areas in 1996 and 1984.espectively, in Shangyu of zhejiang Province, china, to investigate the physico-chemicalproperties and the hyperspectral characteristics of the saline soils and to make an assessment ontheir relationships. The reflectance spectra of saline soils were measured using a spectroradiometerin laboratory. The mean spectral curves of the saline soils from the two sites different inreclamation year showed that the saline soil taken from the recently reclaimed land with highersalinity demonstrated a lower reflectance intensity in the spectral region from about 550 nm to 2300nm. In addition, nine absorption bands, i.e., 4.8 nm, 530 nm, 670 nm, 880 nm, 94. nm, 14.0 nm, 1900nm, 2 200 nm and 2 300 nm, were chosen as the spectral bands to investigate the relationshipsbetween soil physico-chemical properties by means of Pearson correlation analysis. Finally, thefirst two principal components were calculated from nine absorption bands and used to discriminatethe saline soil samples taken from two sampled fields. The results indicate that it is feasible todetect physico-chemical properties of saline soils from fields reclaimed for varying time periods onthe basis of the hyperspectral data.

关键词： coast hyperspectral reclamation saline soils

Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2003年第1期22卷 6-9页

作者： WU QingyinDepartment of Chemistry, zhejiang university, hangzhou 310027, china Department of Chemistry Zhejiang University Hangzhou 310027 China

The heteropoly complexes K_(13)[Ln(GeW_9Mo_2O_(39))_2] centre dot nH_2O (Ln =La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis,infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal ***, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropolycomplexes is a square antiprism consisting of eight oxygen atoms of two GeW_9Mo_2O_(39)^(8-)heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower thanthat of saturated Keggin structure dodecatungstogermanate.

关键词： inorganic chemistry heteropoly complex chemical synthesis lanthanates germanium

MIXED MODEL APPROACHES FOR ESTIMATING GENETIC VARIANCES AND COVARIANCES

在线全文

学校读者我要写书评

暂无评论

生物数学学报 1992年第1期 1-11页

作者： Zhu Jun(zhejiang Agricultural university, hangzhou 310029)

The limitations of methods for analysis of variance(ANOVA)in estimating genetic variances are discussed. Among the three methods(maximum likelihood ML, restricted maximum likelihood REML, and minimum norm quadratic unbiased estimation MINQUE)for mixed linear models, MINQUE method is presented with formulae for estimating variance components and covariances components and for predicting genetic effects. Several genetic models, which cannot be appropriately analyzed by ANOVA methods, are introduced in forms of mixed linear models. Genetic models with independent random effects can be analyzed by MINQUE(1)method whieh is a MINQUE method with all prior values setting 1. MINQUE(1)method can give unbiased estimation for variance components and covariance components, and linear unbiased prediction (LUP) for genetic effects. There are more complicate genetic models for plant seeds which involve correlated random effects. MINQUE(0/1)method, which is a MINQUE method with all prior covariances setting 0 and all prior variances setting 1, is suitable for estimating variance and covariance components in these models. Mixed model approaches have advantage over ANOVA methods for the capacity of analyzing unbalanced data and complicated models. Some problems about estimation and hypothesis test by MINQUE method are discussed.

关键词： Mixed linear models MINQUE method yariance and covariance estimation random effect prediction.

Genome organization and phylogenetic tree analysis of Garlic virus E,a new member of genus Allexivirus

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第1期47卷 33-37页

作者： CHEN Jiong & CHEN JianpingCollege of Life Sciences, zhejiang university, hangzhou 310029, china Virology Department, zhejiang Academy of Agricultural Sciences, {4. 310021, china College of Life Sciences Zhejiang University Hangzhou China Virology Department Zhejiang Academy of Agricultural Sciences Hangzhou China

The complete sequence of an Allexivirus iso-lated from garlic plants in Yuhang City, zhejiang Province, china had been determined. The single-strand, positive RNA genome was 84.1 nucleotides in length excluding poly(A) tail. The genome organization of this virus was similar to that of the other Allexiviruses but only with 62.8%-64.8% nucleo-tide acid identities. The amino acid sequences of proteins encoded by ORFl-6 shared 67.6%-78.5%, 55.4.-66.2%, 56.7%-66.4.,4..3%-55.6%,66.3%-79.7%and 52.2%-68.8% identities with those of the others respectively. The homology range between it and the other Allexiviruses was similar to that between the other distinct species in this genus. A more comprehensive comparison using all available CP amino acid sequences showed that it shared only 63.9%-79.8% amino acids identical with the others. Therefore, it had been considered as a new member of the genus, named as garlic virus E (GarV-E). Phylogenetic analysis confirmed GarV-E as a distinct member and the correct names

关键词： genus Allexivirus garlic virus E nucleotide sequence classification.

Role of Organic Matter in Formation and Stability of Aggregates in Mulberry Plantation Soils

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2001年第2期11卷 185-188页

作者： LU SHENGGAO Collage of Environmental and Resource Sciences, zhejiang university, hangzhou 310029 (china) 浙江大学浙江杭州 310029

The role of organic matter in the formation and stability of soil aggregates in mulberry plantation in the Hang-Jia-Hu Plain, northern zhejiang Province, was evaluated in this study. A positive correlation was found between water-stable aggregate contents and organic matter contents in the mulberry plantation soils, which supported the hypothesis that organic matter was the main cementing agent in formation of aggregates. A close correlation was also found between stability of aggregate and organic matter contents. Regression analysis showed that total nitrogen content was also an indicator of water-stable aggregate content and stability. The aggregate size distribution indicated that the water-stable aggregates 1--0.25 mm in diameter were the major component of the aggregates in the mulberry plantation soils. The organic matter contents of aggregates ranging from 5 to 0.25 mm in diameter increased with the decrease of aggregate sizes, and the aggregates 1-0.25 mm in diameter had the maximum organic matter content.

关键词： mulberry plantation soil organic matter water-stable aggregates