四倍

The meiosis observation demonstrated the genomes of our autotetraploid materials were all 2n = 48, the same as those in mitosis observation.

所有四倍体材料的染色体组成均为2n = 48，这与有丝分裂的结果一致。

Embryo development and origin of twin-embryo of autotetraploid rice with twin-embryo seedlings were observed and verified.

利用激光扫描共聚焦显微技术对同源四倍体双胚苗水稻的受精过程、胚胎发育过程和双胚来源进行观察鉴定。

Biological effects of autotetraploid rice after ion beam implantation of low energy N+.

低能氮离子注入同源四倍体水稻的生物学效应。

From 1996 to 2005, someautotetraploid rice had been selected and improved. T-test showed that seed setincreased obviously. The relationships among yield characters of autotetraploid ricewere analyzed.

从1996年到2005年对部分同源四倍体水稻进行了连续选择改良，T检验表明经过9年的选择改良，其结实率显著提高。

To establish a new technique for in vitro rapid propagation and conservation of germplasm of autotetraploid plant of Plalycodon grandiflorum, basal MS medium supplemented with different hormones was filtrated and optimized by using uniform design and orthogonal design.

为了建立优良同源四倍体桔梗的快速繁殖和离体保存技术，采用均匀设计和正交设计以添加不同激素的MS培养基为基本培养基进行筛选和优化。

Plalycodon grandiflorum ; Autotetraploid ; Uniform design ; Orthogonal design ; In vitro conservation

桔梗；同源四倍体；均匀设计；正交设计；离体保存

It is suggested that autotetraploidy rices are better females in the distant hybridization due to the fact that they are weaker in sexually reproductive ability.

结果暗示由于同源四倍体水稻具有比较弱的有性生殖能力，在远缘杂交中它们是比较好的杂交母本。

At least the average term to maturity for gilts is 14 years; it is about four on American central-government debt.

这个大约是美国中央的政府债务的四倍。

And then some ellipses that AUGR estimator is better than the OLS estimator and AUGL estimator is better than the OLS estimator are given, respectively.Second, the definition of the almost unbiased unified biased estimator is proposed. This definition includes the familiar almost unbiased estimators in literatures, and it is the unified expression of the familiar almost unbiased estimators. Followed the biased and variance are compared of AUUB estimator and the unified biased estimator, respectively. AUUB estimator has smaller bias than UB estimator and the variance of AUUB estimator is between the variance of UB estimator and 4 times of the variance of UB estimator. Finally the properties of AUUB estimator are discussed. The conclusion is gained that there are parameters made AUUB estimator is better than OLS estimator in terms of their mean square error. The sufficient and necessary condition that AUUB estimator is admissible is given. The ellipse is given that AUUB estimator is

然后给出了几乎无偏统一有偏估计的定义，该定义包括了文献中常见的几乎无偏估计，实现了常见几乎无偏估计的统一表达式；接下来我们比较了几乎无偏统一有偏估计与统一有偏估计的偏度与方差，得出了几乎无偏统一有偏估计比统一有偏估计有较小的偏度，几乎无偏统一有偏估计的方差介于统一有偏估计的方差与统一有偏估计的方差的四倍之间的结论；最后我们对统一有偏估计的主要性质作了讨论，证明了存在参数K，S使得几乎无偏统一有偏估计在均方误差意义下优于最小二乘估计的结论，给出了几乎无偏统一有偏估计为可容许估计的充要条件，还给出了在均方误差阵意义下几乎无偏统一有偏估计优于最小二乘估计的椭球。

In this study, we found interesting two-cell stage embryos, which had a monopolar spindle in one blastomere and a bipolar spindle in the other during the second mitosis in a batch subjected to tetraploidization treatment.

在诱导四倍体过程中，我们发现了有趣的二细胞期胚胎现象，在第二次有丝分期间，它的一个分裂球中有一个单极纺锤体，二另一个有一个双极纺锤体。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。