四倍的

The structure and expression pattern of each storage protein was investigated using one-dimensional SDS-PAGE. Our results showed that the protein content of each fraction in endosperm of autotetraploid rice line is mostly higher than that of its corresponding diploid rice line.

结果表明：同源四倍体水稻胚乳蛋白各组分含量与相应的二倍体相比，大部分呈增加趋势；同源四倍体水稻胚乳蛋白的亚基类型与相应的二倍体水稻基本一致，仅在全蛋白电泳和清、球蛋白电泳中各发现1条差异条带。

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。

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。

Tetraploid organisms may arise by the fusion of two diploid gametes that have resulted from the nondisjunction of chromosomes at meiosis, or by nondisjunction of the chromoosomes during the mitotic division of a zygote.

四倍体的产生可能是由于两个二倍体配子发生融合，这种二倍体配子又是在减数分裂中染色体不发生分离而形成。四倍体也可能因为受精卵进行有丝分裂时染色单体未发生分离而形成。

Results showed that the PMC meiosis of autotetraploid was similar to the diploid except some particularities. In metaphase Ⅰ, multivalent, quadrivalent, trivalent, bivalent and univalent were observed and some of the chromosomes were found not to rank on the metaphase plate and so did in metaphase Ⅱ cells. In anaphase Ⅰ and anaphase Ⅱ cells, there were lagging chromosomes, chromosome bridge and fragment. During anaphase Ⅱ and telophase Ⅱ, chromosome segregation was not synchronous or equal. At tetrad stage, dyad, triad, tetrad with micronucleus and polyad appeared.

结果表明，同源四倍体花粉母细胞减数分裂过程与二倍体相比，中期Ⅰ染色体构型复杂，有多价体、四价体、三价体、二价体和单价体；中期Ⅰ及中期Ⅱ有部分染色体没有排列在赤道板上；后期Ⅰ及后期Ⅱ出现落后染色体、染色体桥及断片；后期Ⅱ和末期Ⅱ有染色体不同步分离及不等分裂的现象；四分体时期还出现二分体、三分体、含微核的异常四分体及多分体。

With the stable genetic tetraploidy and the fertility in the nature environments, this allotetraploid population presented the key factors to form a new species with 200 chromosomes.

异源四倍体鲫鲤稳定的染色体数目和正常的性腺结构以及自然条件下的生殖传代行为，说明该异源四倍体鲫鲤已成为一个染色体数目为4n=200、遗传性状稳定的新型四倍体鱼群体，具备形成新种所需的关键因素。

With the stble genetic tetraploidy and the fertility in the nature environments, this allotetraploid population presented the key factors to form a new species with 200 chromosomes.

异源四倍体鲫鲤稳定的染色体数目和正常的性腺结构以及自然条件下的生殖传代行为，说明该异源四倍体鲫鲤已成为一个染色体数目为4n=200、遗传性状稳定的新型四倍体鱼群体，具备形成新种所需的关键因素。

The improved L.D.Cua method was used to induce tetraploid of Trichosanthes kirilowii Maxim. The suitable treating time of 0.2% colchicine, the morphology characters and cytology identification between plants of diploid and obtained tetraploid were studied.

采用改良L.D.Cua法诱导短把栝楼获得四倍体，研究了0.2%浓度的秋水仙碱诱导短把栝楼染色体倍性变异的最佳处理时间、四倍体栝楼与原栝楼的形态特征及其四倍体与二倍体的细胞学鉴定。

Article 21 People's governments at different levels shall reinforce their leadership in fire prevention of the ecological public welfare forest, implement the system of administrative leaders' responsibility for forest fire prevention, and ensure the supply of sufficient funds for forest fire prevention and suppression. The forestry administrative department of the people's government at or above county level shall set up publicity boards for forest fire prevention in the forest area and peripheral area hereof, construct fire-prevention forest belt or forest fire obstruction passage and establish fire suppression force.

第二十八条违反本办法第二十四条第一款规定，在生态公益林区域内进行采种、采脂等经营活动，致使森林、林木受到毁坏的，依照《中华人民共和国森林法》第四十四条的规定，赔偿损失；由县级以上人民政府林业主管部门责令停止违法行为，补种毁坏株数1倍以上3倍以下的树木，可处毁坏林木价值1倍以上5倍以下的罚款；拒不补种树木或者补种不符合国家有关规定的，由林业主管部门代为补种，所需费用由违法者支付。

Pitardii,all from the Jinshajiang Valley of Yunnan and Sichuan, were cytologically studied in this work. Among 34 populations of C.reticulata studied here, 21 were found to be tetraploids (2n=60), 11 hexaploids (2n = 90), and the remaining two diploids (2n = 30). Tetraploid was reported in C. reticulata for the first time and its karyomophology was studied.

reticulata及其两个近缘种(怒江山茶C.saluenensis和西南山茶C.pitardii)进行了细胞学研究。34个居群的云南山茶花中，21个居群是四倍体类型(2n=60)，11个居群是六倍体类型(2n=90)，另2个居群为二倍体(2n=30)，云南山茶花的四倍体类型为首次发现，并且进行了核形态研究。

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。