四倍性

In the self-bred progenies of autopolyploid,we found that a very few chimaeraexist in the cells of root tips,but most of them had no change in ploidy. We also found13 diploid plants in the experimental plot (ratio is 0.46%) and can be divided into 4categories.

在部分同源多倍体株系的自交结实后代中，随机取样进行根尖染色体检查，结果表明多倍株系体的自交结实后代倍性没有变化，但发现有个别细胞为不同倍性的嵌合体；田间观察到分离出来的极少数正常二倍体，占0.46％，按照形态特征可以分成四个不同的类型。

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。

The operation of these recessive genes influencing crossability with rye was similar to that of hexaploid common wheat.

通过与六倍体普通小麦相比较，结果表明四倍体小麦的可杂交性系统与六倍体小麦的可杂交性系统的作用方式是类似的。

F〓 of transgenic allotetraploid fish containing"all-fish"transgene——pCAgcGHc was obtained respectively by inbreeding and gynogenesis. Positive rate of pCAgcGHc detected by PCR was 90％ in F〓 of transgenic allotetraploid fish produced by inbreeding, while most F〓 of transgenic allotetraploid fish produced by gynogenesis showed diploidy measured by flow cytometer. The results above imply that developing the pure line of transgenic allotetraploid fish through inbreeding is feasible, but the operation should be modified if gynogenesis is introduced.

采用近交和雌核发育方法培育出转pCAgcGHc基因异源四倍体鲫鲤F〓代，通过PCR检测，外源基因pCAgcGHc在近交转pCAgcGHc基因异源四倍体鲫鲤F〓中的整合率为90％，而流式细胞技术检测雌核发育转pCAgcGHc基因异源四倍体鲫鲤F〓的倍性多为二倍体，说明通过近交筛选转基因异源四倍体鲫鲤纯系的方法是可行的，但是通过雌核发育来筛选转基因异源四倍体鲫鲤纯系还要就方法上进一步的改进。

The number of chloroplast in stomata guard cell, density, length and width of stomata were observed.

以苹果和梨的二倍体和多倍体为试材，比较了气孔保卫细胞叶绿体数目、气孔密度、气孔长和气孔宽四个性状与倍性的关系，分析各个性状用于倍性鉴定的可靠性，并采用两类性状同时进行判别分析，建立判别分析方程。

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%。

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。

The genetic analysis and improvement of characters, such as tuber processing quality traits and yield components which tend to be quantitatively inherited, are far more difficult than those at diploid potato. Reviewing the earlier studies indicated that a few systematic investigations on genetics of important traits in potato were untaken and most focused on estimates of combing ability for agronomic traits due to limited materials and methodologies available.

利用二倍体材料简化了遗传分离比例、可应用现有的二倍体遗传模型进行遗传分析并更有效的挖掘和利用二倍体资源中的优异基因，进而通过倍性育种及遗传工程育种将有利性状转育到四倍体普通栽培品种。

Thus, the meiotic chromosome cofigurations showed that the tetraploids and hexaploids in C.reticulata allopolyploids, and the appearance of a few tetravalents in some populations might indicatehomology of chromosomes in different genomes to some extent.

根据减数分裂的构型，我们认为，四倍体和六倍体分别为异源四倍体和异源六倍体，少数四价体的存在表明染色体有部分同源性。

Most primers amplified same bands in diploids, tetraploids and hexaploids. It suggest that D and AB genomes have high homology and D genomes be successfully transferred from diploid to hexaploid.

从供试的绝大多数引物均能在不同倍性小麦中扩增出相同的条带证明了D染色体组和AB染色体组间存在着很高的同源性以及利用二倍体和四倍体小麦杂交人工合成六倍体小麦的真实性。

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。