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31.
从大连海域患“腐皮综合症”的养殖刺参肠道中分离纯化到1株优势细菌LNUB415,经人工回接感染试验确定其对刺参具有较强的致病性.经形态学、生理生化和16S rDNA序列分析,该菌被初步鉴定为蜡样芽胞杆菌(Bacillus cereus).从多种具有免疫增强作用的中草药中筛选到抑菌效果最好的黄连,可使刺参死亡率降低30%.  相似文献   
32.
The metazoan parasites of four populations of the chub mackerel Scomber japonicus were analysed from two localities in the Atlantic Ocean (Madeira Islands, Portugal, and Rio de Janeiro, Brazil) and two localities in the Pacific Ocean (Callao, Peru, and Antofagasta, Chile), collected during 2002 and 2003. A total of 373 fish specimens were studied and 34 metazoan parasite species were obtained. Parasites identified from the populations of chub mackerel studied could be separated into three categories: parasites with a wide distribution, present in the Pacific and Atlantic, parasites proper of the Pacific Ocean and parasites proper of the Atlantic Ocean. The analyses of some highly specific parasites of the genus Scomber ( i.e. monogeneans of the genus Kuhnia and didymozoid digeneans) strongly suggest the need for a revision of the taxonomic status of chub mackerels from the Atlantic and Pacific coast of America. The results demonstrated the usefulness of parasites as adequate tools to clarify the taxonomic status of their hosts.  相似文献   
33.
The numbers of first-batch eggs and workers (minims) in a carpenter ant Camponotus japonicus are not fixed but are regulated in response to various internal and external factors of founding queens. The initial body weight of founding queens was positively correlated with the number of minims. The amount of queen weight loss during the founding period was highly correlated with the number of minims. The numbers of first-batch eggs and minims for artificially fed queens were significantly greater than those for control group queens and for unfed queens, respectively. The number of eggs laid by a queen increased when eggs deposited in the early stage of founding were removed. In contrast, artificial addition of alien eggs reduced the number of eggs laid by a queen. The adaptive implications of this flexibility in the production of the first-batch brood in C. japonicus are discussed. Received: December 18, 2000 / Accepted: March 19, 2001  相似文献   
34.
Among leguminous plants, the model legume Lotus japonicus (Regel) Larsen has many biological and genetic advantages. We have developed a genetic linkage map of L. japonicus based on amplified fragment length polymorphism (AFLP), simple sequence repeat polymorphism (SSRP) and derived cleaved amplified polymorphic sequence (dCAPS). The F2 mapping population used was derived from a cross between two L. japonicus accessions Gifu B-129 and Miyakojima MG-20. These parental accessions showed remarkable cytological differences, particularly with respect to size and morphology of chromosomes 1 and 2. Using fluorescence in situ hybridization (FISH) with BAC clones from Gifu B-129 and TAC (Transformation-competent Artificial Chromosome) clones from Miyakojima MG-20, a reciprocal translocation was found to be responsible for the cytological differences between chromosomes 1 and 2. The borders of the translocations were identified by FISH and by alignment toward the L. filicaulis x L. japonicus Gifu B-129 linkage map. The markers from the main translocated region were located on linkage groups 1 and 2 of the two accessions, Gifu B-129 and Miyakojima MG-20, respectively. The framework of the linkage map was constructed based on codominant markers, and then dominant markers were integrated separately in each linkage group of the parents. The resulting linkage groups correspond to the six pairs of chromosomes of L. japonicus and consist of 287 markers with 487.3 cM length in Gifu B-129 and 277 markers with 481.6 cM length in Miyakojima MG-20. The map and marker information is available through the World Wide Web at http://www.kazusa.or.jp/lotus/.  相似文献   
35.
Invasive Aedes mosquito species (Diptera: Culicidae) are of public health concern in Europe because they are either recognized or potential vectors of pathogens. Loop‐mediated isothermal amplification (LAMP) is a rapid and simple method for amplifying DNA with high specificity and efficiency, with the technique having potential for application in the field, including in high‐throughput format. Specific LAMP assays based on rDNA internal transcribed spacers 1 or 2 sequences, considering intraspecies variability at these loci, were developed for Aedes aegypti, Aedes albopictus, Aedes japonicus, Aedes koreicus and the indigenous Aedes geniculatus. No such assays could be developed for Aedes atropalpus and Aedes triseriatus because both loci were too short to serve as target. The assays rely on the clearly visible colour change from violet to sky blue after successful amplification. Sensitivity of egg detection was confirmed with ratios of up to one mosquito egg in 99 other eggs. Simple sample preparation of adults or eggs by mechanical homogenization in water required an additional heat treatment or centrifugation step to avoid non‐specific colour changes. Thus, further technical improvements are needed to render these assays truly field‐applicable, which would greatly facilitate surveillance of these invasive mosquito species and allow for prompt implementation of control measures.  相似文献   
36.
本文根据蕊柱结构将Archineottia 归并于Holopogon,并发表了5个新组合:无喙兰Holopogon gaudissartii (Hand.-Mzt.) S. C. Chen、 印度无喙兰H. microglottis (Duthie) S. C. Chen、锡金无喙兰H. pantlingii (W. W. Smith) S. C. Chen、叉唇无喙兰 H. smithianus (Schltr.) S. C. Chen、 日本无喙兰H. japonicus (M. Furuse) S. C. Chen。  相似文献   
37.
Sixty-five TAC (transformation-competent artificial chromosomes) clones were selected from a genomic library of Lotus japonicus accession MG-20 based on the sequence information of expressed sequences tags (ESTs), cDNA and gene information, and their nucleotide sequences were determined. The average insert size of the TAC clone was approximately 100 kb, and the total length of the sequenced regions in this study is 6,556,100 bp. Together with the nucleotide sequences of 56 TAC clones previously reported, the regions sequenced so far total 12,029,295 bp. By comparison with the sequences in protein and EST databases and by analysis with computer programs for gene modeling, a total of 711 potential protein-encoding genes with known or predicted functions, 239 gene segments and 90 pseudogenes were identified in the newly sequenced regions. The average gene density assigned so far was 1 gene/9140 bp. The average length of the assigned genes was 2.6 kb, which is considerably larger than that assigned in the Arabidopsis thaliana genome (1.9 kb for 6451 genes). Introns were identified in approximately 73% of the potential genes, and the average number and length of the introns per gene were 3.4 and 377 bp, respectively. Simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated based on the nucleotide sequences of the genomic clones obtained, and each clone was mapped onto the linkage map using the F2 mapping population derived from a cross of two accessions of L. japonicus, Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.  相似文献   
38.
The family Megalyridae is recorded from Japan for the first time on the basis of two new species, Carminator helios and C. japonicus. This is the northernmost record of living Megalyridae, although fossil species are known from regions of the Baltic Sea. Carminator helios can be distinguished from congeners of the Asian and Australian regions by the combination of a long head, deeply excavated frons with convex inner margins, entirely striated postgena, the number of fore tibial spines (more than 16), and a long R1 vein. Carminator japonicus is distinguishable from other species by the combination of an orange‐colored metasoma, a weakly excavated frons, and an elongate vertex. This species was collected from the canopy of Acer pictum. Additional characters that distinguish species of the genus Carminator are discussed.  相似文献   
39.
Protoplasts were isolated by enzyme digestion from leaf of Japanese butterbur (Petasites japonicus). The enzyme incubation mixture consisted of 4% (W/V)cellulase RS, 2% (W/V) hemicellulase, 1% (W/V) pectinase-dissolved Y-23 and polygalacturonase in a solution of 0. 5 mol/L mannitol at pH 5.7 . In the basic medium of 1/4 MS inorganic salts and 1/2 MS vitamins supplemented with 2 mg/L NAA, 0. 2–0. 5 mg/L BA, 0. 5 mol/L mannitol and 10 g/L sucrose, the cells divided luxuriantly. Regenerated plantlets were formed from callus after bud induction and root initiation.  相似文献   
40.
The hatching dates of Encrasicholina punctifer and Engraulis japonicus larvae collected in the coastal waters off Tanshui River Estuary during the fishing seasons of 1992 and 1993 indicated that these two anchovies had protracted spawning seasons, which resulted in multiple recruitment cohorts. Encrasicholina punctifer larvae recruited to the estuary from October to March, while the majority of E. japonicus larvae came in March-May and to a lesser extent in October and November. The E. punctifer larvae on arrival to the estuary were 17·4–35·6 mm in length, 167ndash;89 days old and had growth rates of 0·4–1·0 mm day−1, E. japonicus larvae were 12·1–32·7 mm in length, 19–62 days old and had growth rates of 0·7–0·9 mm day−1. Growth rates were significantly different among cohorts and positively correlated to water temperature.  相似文献   
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