查询词典 tetraploid

That indicated the availability of SRAP technique in studying genetic variability in Arachis. Estimates of genetic distance among the 28 accessions Arachis section ranged from 0.12 to 0.75 with average genetic distance of 0.42. A genetic distance clarified that A-genome A. duranensis was most closely associated with tetraploid germplasm, which could be A-genome donors. Dendrogram of cluster analysis classified 28 accessions Arachis section into two groups: one including tetraploid germplasm, and A.

聚类分析表明，28份花生材料间的遗传距离变幅为0.12~0.75，平均为0.42，A基因组物种Arachis duranensis与栽培种花生的亲缘关系最近，可能是栽培种花生的A基因组的供体。28份种质分为两大类，第一大类包含四倍体种质及A基因组的A。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Compared diploid fodder beet with tetraploid fodder beet, tetraploid plants put up characteristics of bigger and thicker dark green leaf, more folds on leaf, stronger footstalk and so on .we can take those characters as the advancing index in testing tetraploid fodder beet.

饲用甜菜四倍体植株与二倍体植株相比，表现出叶片增大变厚，叶色浓绿，叶面多皱褶，叶柄粗壮等特点，可以将这些特点作为饲用甜菜四倍体田间初步筛选的指标。

The results showed that N uptake of diploid andtetraptoid were lower than those of Hexaptoid and octoploid at over wintering and afteranthesis, but the capability was higher from jointing to anthesis. Diploid and tetraploid hadlower N distribution in leaf, and had higher N distribution in else vegetative parts at anthesis. And had lower N distribution in grain, higher N distribution in else vegetativeparts at mature. The N transfer amounts and its contribution to grain N accumulation ofDiploid and tetraploid were higher than Hexaploid, but the NTE and contribution of Naccumulation to grain N were lower.

结果表明，与普通小麦和小黑麦相比，二倍体和四倍体材料在越冬前和花后氮素吸收能力较低，在拔节到开花期间较高；开花期氮素在叶片中的积累较少，其他营养器官积累较多，成熟期营养器官中的氮素分配较高，籽粒中氮素分配较少；具有较高的氮素运转量，但运转效率比较低；花后营养器官氮素运转对籽粒氮素积累的贡献率较高，花后吸收氮素的贡献率较低。

The results showed that the number of chromosome, which was from the cultured seedlings of meristem tip and the rank seedlings of meristem tip, was not altered, both the number were 2n=16,the hereditary stability of callus and regeneration plant was poor; and the variation percentage of chromosome in callus was 43.4%, among which haploid accounted for 6.7%, triploid accounted for 2.5%,tetraploid accounted for 10%,pentaploid accounted for 4.2%,hexaploid accounted for 3.3%,septuploid accounted for 4.2%,octoploid accounted for 3.3%,dysploid accounted for 9.2%;the chromosome variation percentage of differentiation seedlings derived from callus was11.7%,among which haploid was 6.7%,triploid accounted for 1.7%,tetraploid was 3.3%.

结果表明，茎尖分生组织培养的幼苗及丛生苗遗传稳定，其染色体未发生倍性变异，均为2n=16；愈伤组织及其再生苗遗传稳定性较差，愈伤组织染色体数变异率为43.4%，其中单倍体占6.7%、三倍体占2.5%、四倍体占10%、五倍体占4.2%、六倍体占3.3%、七倍体占4.2%、八倍体占3.3%、非整倍体占9.2%；愈伤组织分化苗染色体变异率为11.7%，其中单倍体占6.7%，三倍体占1.7%，四倍体占3.3%。

Diploid, triploid, tetraploid, pentaploid and hexaploid hybrid plants have been recovered from protoplast fusion, among which the tetraploid ones accounted for almost90%.

这些体细胞杂种有二倍体、倍体、倍体、倍体和六倍体，但主要是四倍体。

Tetraploid veliger were carried out with four chemicals on this scallop in 1998—2000. Tetraploid were induced by inhibition of the polar body and first mitosis with cytochalasin B, colchicine, 6-DMAP and caffeine combined with CB, respectively.

中文摘要：1998—2000年采用细胞松弛素B、秋水仙素、6-二甲基氨基嘌呤(6-DMAP)以及咖啡因等药物抑制虾夷扇贝第一极体(PB1)释放、PB1和第二极体(PB2)释放以及抑制第一次卵裂等方法，诱导虾夷扇贝四倍体。

Tetraploid embryo can be used as a power tool on life science such as on the research of mechanism in the inchoate embryo development which regulatory the cell volume, mumber and cleavage rate. Tetraploid embryo can also be used to change the ratio of genome of parents on the progeny; More importantly we can obtain completely ES cell-derived mice through tetraploid embryos complementation and the ES mice is significance in analysis of gene function and built disease mouse modle.

在生命科学研究中，四倍体胚胎可以作为研究机体发育的有力工具，例如，用它来研究早期胎儿发育过程中调节细胞体积、数目以及分裂速率的机制，也可以用它来改变双亲基因组在子代中的分配比例；更为重要的用途是通过四倍体补偿作用获得完全由ES细胞发育而来的个体，ES小鼠的获得对基因功能的分析、疾病动物模型的建立有十分重要的意义。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。