四分体

高水平的ZT/IAA有利于大孢子母细胞和花粉粒的形成，而大孢子四分体的形成则需要高的GA3/ZT比值。

It appears however that the formation of megaspore tetrad associated with the high GA3 / ZT ratio .

四分体到小孢子单核期和小孢子二核后期至成熟花粉期不育花蕾ABA含量仍高于可育花蕾。

From tetrad stage to microspore stage , the ABA content in sterile buds was higher than fertile buds .

有些G-四分体能够与血晶素结合形成具有类过氧化物酶特性的复合物，被称作DNA酶。

The G-quadruplex can bind hemin to form a catalytic complex with the peroxidase activity .

为了产生免标记的荧光信号，该设计将能够形成G-四分体结构的DNA序列的一部分隐藏在DNA发卡结构中。

In order to acquire label-free fluorescence signal , we hide partial sequence of the G-quadruplex into one of the hairpins .

大孢子母细胞、大孢子四分体及功能大孢子中含较少不溶性多糖，但却含丰富的RNA和蛋白质。

The insoluble polysaccharides are at very low level in the MMC , tetrads and functional megaspore stages while RNA and protein are at higher level in all of them .

主要研究结果如下：（1）在沈阳地区，亚洲百合花粉母细胞减数分裂约在5月20日左右开始启动，从减数分裂细线前期至四分体减数分裂完毕大约需要7d左右。

The results are as follows : ( 1 ) In Shenyang , PMCs started to meiosis about May 20 and lasted approximately 7 days in Asiatic Hybrid .

MS-4花粉败育的时期，是在小孢子四分体分开至单核花粉粒时期。

Pollen abortion of MS-4 was in the single nucleus pollen grain stage after the division of microspore tetrad .

结果表明：（1）在营养器官与生殖器官中，IAA含量自四分体时期均低于对照，在花药中随CHA剂量增加IAA含量降低幅度增大；

The results indicated : ( 1 ) The IAA content was lower than CK since the quardrant stage in the nutrient organ and reproductive organ , while the change extent in the anthers was closely related to the dosage of CHA ;

ABA和ZT处理在药隔分化期及四分体时期均使小麦穗内源IAA、GA3、ZR含量降低，内源ABA含量升高。

The contents of endogenous IAA , GA3 and ZR were much lower by treated with ABA and ZT than those of the control plant at the stage of differentiation of anther chamber and formating stage of tetrad , but those of endogenous ABA were higher .

8-602A败育发生于孢原细胞时期至四分体时期，主要是孢原细胞时期。

The abortion of 8-602A occurred from the archesporial cell stage to the tetrad stage , mainly at the stage of archesporial cell .

但在四分体分化期，药隔期之前ZT处理有增加幼穗可溶蛋白含量的趋势，雌雄蕊分化期处理则显著降低了幼穗可溶性糖的含量。

Furthermore , the former treatment of ZT increased the content of soluble protein and decreased the content of the soluble sugar of young spike . The contents of endogenous plant hormones varied with the stages of the young spike differentiation and development .

四分体时期，绒毡层细胞内部结构开始解体。

In tetrad stage , the structures of tapetal cells begin to dissociate .

四分体时期观察到二分体和三分体。

Dyads and triads were produced at tetrad stage .

小孢子四分体为四面体型，成熟花粉粒为2-细胞型。

Pollen grains are 2-celled at the dispersal stage .

绒毡层细胞在四分体&单核早期发生增生；

Tapetum cell hyperplasia from the tetrad to the single nucleus early period .

这个现象在早期四分体阶段出现。

This phenomenon occurs in the early tetrad stage .

四分体期，每个四分体微核数平均2.82个。

The numbers of micronucleoli in tetrad were 2.82 per tetrad on an average .

小孢子败育发生在四分体形成以后。

Microspore abortion occured after the tetrad formation .

少数初级精母细胞可以在体外进行减数分裂形成一个精子细胞的四分体。

Minority of spermatocytes occurred meiosis to form a quadrant of spermatids in vitro .

四分体时期绒毡层肥大增厚可能与花粉败育有关。

Hypertrophy and hyperplasia of tapetum at tetrads stage were related to pollen abortion .

异常四分体频率各代分别为0.16、0.13和0.66。

Abnormal tetrad rates in different generations were 0.16 , 0.13 and 0.36 respectively .

四分体线形，少数三分体。

The tetrads are linear , few triads .

木兰溪两岸浅井水对紫露草四分体微核率的影响

Effect of Shallow Well Water along the Mulan Stream on Tradescantia paludosa Tetrad Micronucleus Frequency

四分体细胞于是分裂形成八细胞胚。

The cells of the quadrant in turn become partitioned to from the eight-celled embryo .

四分体时期出现二分体、三分体、含微核的异常四分体及多分体。

At tetrad stage , dyad , triad , tetrad with micronucleus and polyad appeared .

前期Ⅱ和四分体时期可观察到核外染色体；

Chromosomes out of nuclei can be seen both at prophase ⅱ and tetrad period .

四分体期施肥灌水可显著提高小花结实率，是孕穗期肥水措施决策的重要生育标志。

The application of fertilizer and water in the quadrant stage may increase the fruiting ratio .

小孢子母细胞减数分裂属于同时型，小孢子在四分体中的排列方式多数为四面体形，少数为十字交叉形。

Microspore mother cells meiosis was conformed to simultaneous type with mostly tetrahedral and decussate tetrad .

花粉败育的过程从四分体开始，细胞质内液泡逐渐增大，接着细胞器解体，细胞核解体。

The process of pollen abortion begins with vacuole formation and gradual enlargement in the tetrad .

植物根尖微核与四分体微核技术对诱变剂和工厂废水的监测试验

The Application of Plant Root-tip Micronucleus and Tetrad Micronucleus Bioassay for Monitoring Industrial Waste Water and Mutagents