四倍的

But the abnormal phenomena in autotetraploid rice were more than that in diploid rice.

同源四倍体水稻胚囊发育过程与二倍体基本一致，但在同源四倍体水稻胚囊的形成和发育过程中出现了较多的异常现象。

Study on the pollen fertility and the process of pollen formation and development in autotetraploid rice showed that the pollen fertility was high (78.33%), though many abnormities appeared in this process.

通过对5个品种的同源四倍体水稻花粉发育过程和13 个品种的花粉育性调查结果表明，同源四倍体花粉平均育性为78.33%，明显比二倍体（91.85%）低。

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。

Their water use efficiency exceed that of duplation clone under drought stress, which show that tetraploid clones have more yield at the same irrigation.

两个四倍体品种的水分利用效率无论在哪种干旱处理方式下都显著优于二倍体，说明在同等供水条件下，四倍体品种有较大的生物量产出。

Pooling together thedata from comparing the 4x original varieties with their corresponding 2x varietiessince 1979,it was found,that tetraploidy could cause variation of manyagronomic traits.

自1979年对四倍体水稻原种(4x)和相应的二倍体水稻品种(2x)进行了对比，结果发现，四倍体水稻原种的许多农艺性状发生了变化。

That indicates there might be differences in respiring and feeding between diploid and triploid Pacific oysters.

二、对四倍体牡蛎精子的透射电镜观察结果表明，四倍体太平洋牡蛎的精子的形态结构与其二倍体基本相同，都是由头部、中段和鞭毛三个部分组成。

Herbacium were isobilateral leaves, and those of G. hirsutum and C. barbadense were dorsiventral leaves. The reciprocal F〓 of cross G. arboreum×G. herbacium were also isobilateral leaves, while reciprocal F〓 cross of G. hirsutum×G. barbadense were also dorsiventral leaves. The quadrispecific hybrids F〓 were isobilateral leaves, regardless of their cytoplasms. The structures of the leaf stalks and the stems were analogous to each other among the four cultivated cotton species except their diameters varied with species.

四个栽培棉种及其种间杂种F〓的形态学和细胞遗传学观察四个栽培棉种的植株、叶片、茎杆以及花器等器官都有明显的差异；叶片、茎杆以及叶柄的横切面结构观察结果表明，两个二倍体栽培棉种的叶片横切面构造为等面叶，两个四倍体栽培棉种却均为背腹叶；F〓正反交的叶片也为等面叶，F〓正反交F〓仍为背腹叶，而它们的四元杂交种均为等面叶；四个栽培棉种的叶柄和茎的横切面结构基本一致，只是直径形状和和维管束多少的不同，四元杂种的叶柄和茎的横切面结构的差异不明显。

Because the CMYK color business card printing and making basic membership card is based on the dot to overprint colouration and instead use spot color is basic to business card printing and membership card production, although typically spot color is only partial use of the image, but valuation, it is conventional to general printing inks price to estimate; in addition, if the same suites have four business card printing and membership card making color, cards and membership cards for the purpose of making is tantamount to another color, if the business card printing and membership card making machines have no spare business card printing and membership card production unit (for example, less than four color business card printing and membership card making machine or four-colour business card printing and membership card making machine), you have to spend double the amount of real time business card printing and membership card production cost is higher.

因为CMYK四色制卡和会员卡制息根基因此网不背叠印呈色，而搁置专色则根基以实不天制卡和会员卡制息，尽管凡是专色只是在图像的部分搁置，但估价时，不惯上却因此凡是印墨的两倍代价来估算的；此外，如果同版背还来有了四个制卡和会员卡制息色，差制卡和会员卡制息而言不离即是众了一个颜色，如果制卡和会员卡制息机操纵众余的制卡和会员卡制息单位（如超出四色的制卡和会员卡制息机或四色制卡和会员卡制息机），不离又给众花一倍的工夫来制卡和会员卡制息，不败本也不离更高了。

The tetraploids of C.reticulata from the localities with the altitude of over 1800 m were gross-morphologically similar to the hexaploids, but those growing between 1100 ～1800 m were different to some extent from the hexaploids.

中海拔(1800m)以上的四倍体的云南山茶花外部形态特征与六倍体类型比较相似，而低海拔(1100～1800 m)的四倍体类型的外部形态特征则有些不同，但核形态结构是比较相似的。

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。