四分体时期

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 .

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 .

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 .

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 .

二分体、三分体、四分体时期，胼胝质荧光主要存在于大孢子之间的横壁上，侧壁内胼胝质荧光较弱。

Callose exists mainly in transverse walls during dyad , triad and tetrad stages , a little in side walls .

结果表明，小孢子的败育发生在小孢子母细胞时期、四分体时期以及单核小孢子时期。

The results showed that the microspore abortion occurred at the stage of microspore mother cell , tetrads and uninucleate microspore .

造孢细胞，大孢子母细胞和四分体时期，周缘细胞仅1层。

There is only one layer of parietal cells at the stage of sporogenous cell , megaspore mother cell and tetrad .

如此，那些在早期减数分裂过程中所引起的染色体断裂部分，将在四分体时期变成微核。

The chromosome fragments which are induced by the agent at the early meiotic stage become micronuclei at the tetrad stage .

结果表明：不育系A2的绒毡层细胞在四分体时期出现异常，小液泡增多，至单核期汇合形成大液泡，绒毡层细胞异常膨大；

The results revealed that the tapetal cells of the male sterile A2 developed abnormally at tetrad stage , and they became vacuolated and numerous small vacuoles are present .

在花粉母细胞和四分体时期，不育系细胞中多糖物质的含量稍高于保持系细胞中的含量，但它们之间差异不显著。

At both tetrad and pollen mother cell stages , the amount of polysaccharides in pollen cells of male sterility line was slightly higher than that of its maintainer lines .

四分体时期，保持系和不育系四分体形成正常，但两者中层和绒毡层差异较大。保持系中层细胞排列整齐，细胞核清晰可见，绒毡层细胞质浓郁发达；

At the tetrad stage , the pollen-mother cells in sterile and fertile anthers went through meiosis and formed normal tetrad while there were many differences between their middle layer and tapetum .

[2]孢子母细胞减数分裂形成四分孢子，进入四分体时期。

And the protoplasts fused and intrude among the sporocytes . [ 2 ] The sporocytes form tetraspores by meiosis and enter the tetrad phase .