四倍性

So, the abnormality of embryo sac was one of the factors that induce low seed setting percentage in autotetraploid rice.

从对13个品种的成熟胚囊育性调查的结果来看，同源四倍体水稻胚囊育性是影响其结实率的原因之一。

Thus,it is important that elucidate the genetic control of the crossability of Chinese tetraploid wheat with rye.

因此，研究中国四倍体小麦的亲和性问题具有特殊的意义。

Autotetraploids from diploidy leaves of Paulownia elongata on the double layer MS media supplemented with 0.1 mg/L NAA and 15 mg/L BA(optimal organogenetic medium to the leaves of diploidy seedlings) with different colchicines concentrations were induced,chromosome numbering of the plant root tip cells and DNA content analysis of the leaf single cell were used to analyse the autotetra ploids.

在含不同浓度秋水仙素的MS+0.1mg/L NAA+15mg/L BA双层培养基上进行兰考泡桐四倍体植株诱导试验，并通过变异植株根尖细胞染色体观察和叶片单细胞DNA含量测定进行倍性分析。

The distribution of hybrid chlorosis Ch1 gene and the T-type cytoplasm fertility restoring genes in Chinese endemic wheats were studied using the testors QA1104 (T-type cytoplasm sterile line, with hybrid chlorosis Ch2 gene) and Khapli emmer (with hybrid chlorosis Ch1 gene).

本研究以T型不育系QA1104（具有杂种黄化基因Ch2）和Khapli（具有杂种黄化基因Ch1）为测验种，对中国特有小麦等六倍体小麦类型和一些四倍体小麦类型中的T型胞质育性恢复基因和杂种黄化Ch1基因的分布进行了研究。

In white participants, the 1919T allele was associated with increased risk of stroke and cardioascular mortality, and in black participants, homozygosity for the 790T allele was associated with a fourfold increased risk of MI compared with homozygosity for the 790A allele.

在白人参与者中，1919T等位基因与中风和心血管病死亡率的危险增加有关，而在黑人参与者中，790T等位基因的同合子性比790A等位基因的同合子性与心肌梗死危险的关系高四倍。

In conclusion, abnormal meiosis of PM-Cs is the cytogenetic causes for fertility reduction of tetraploid melon.

花粉母细胞减数分裂的异常是同源四倍体甜瓜育性低的细胞学原因。

Polymorphism in diploid species G.arboreum was the same as in tetraploid species G.hirsutum,both were 11.84%.

在二倍体棉种中棉的扩增多态性率为11.84%，与在四倍体棉种陆地棉的扩增多态性率相同。

The phylogenetic analysis based on the sequences in this region indicated that the y-type HMW glutenin subunits of Agropyron elongatum species were different from other subunits, whereas the x-type subunits of them were most closely related to that from the B genome.

推测四倍体长穗偃麦草中的E1基因组可能起源于二倍体的E基因组。与来自小麦族的A、B、D和G基因组部分亚基基因的启动子序列比较表明，小麦族的这一区域在进化上是相当保守的，不同基因组来源的序列同源性都在90%以上。

However, analysis of DNA methylation level indicated that the total DNA methylation levels were not significantly different between diploid and autotetraploid. Autotriploid showed a trend of low DNA methylation level. It implied that the alterations of DNA methylation levels were not linear with the autopolyploidy level in watermelon.

有趣地是，二倍体与四倍体西瓜相比DNA甲基化水准却未发生大规模的调整，而三倍体西瓜显示出较为明显的低DNA甲基化水准趋势，表明西瓜同源多倍化过程中其基因组DNA甲基化水准变化与其倍性不成线性关系。

"Wheats are called diploids when they have seven chromosomes, tetraploids when they have fourteen , and hexaploids when they have twenty-one."

其性细胞具有7条染色体的小麦称为二倍体；具有14条染色体的称为四倍体；具有21条的称为六倍体。

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。