这个现象在早期四分体阶段出现。
四分体阶段无微核出现。
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.
四分体阶段有微核。
在四分体和成熟胚囊时期观察到了异常发育现象。
Abnormal development was observed at tetrad and mature embryo sac.
当小孢子从四分体中释放出来，特殊类型的外壁已经形成。
An extine with its specific pattern had already been formed, when microspores were released from tetrads.
大孢子四分体为线形，合点端功能大孢子发育成为蓼型胚囊。
Megaspore tetrad is linear. The chalazal megaspore develops into an embryo sac of Polygonum type.
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.
直线形大孢子四分体，合点端第一、或第二、或第三个大孢子有功能。
The four megaspores that the first one, or the second one, or the third one towards the chala- zal end is functional arrange in a line.
此时每条染色体由一对染色单体构成，这两条联合的染色体称为四分体。
At this point esch chromosome consist of a pair of chromatids and the two associated chromosomes are termed a tetrad.
结果发现小孢子母细胞和四分体小孢子中积累了一些脂滴，但没有淀粉。
The results showed that microspore mother cells and tetrad microspores accumulated numerous lipids but no starches.
双线期时，配对的染色单体开始从四分体中分离，此时常可见染色体交叉。
In diplotene the pairs of chromatids begin to separate from the tetrad formed by the association of homologous chromosomes.
小孢子四分体为四面体型排列，成熟花粉有2 -细胞和3 -细胞型2种。
The microspores are arranged in a tetrahedral tetrad. The mature pollen grains are of the 2-celled and 3-celled types.
甘兰型油菜萝卜细胞质雄性不育系的花粉败育发生在四分体至单核花粉粒阶段。
There occurs pollen abortion during the stage from tetrad to single nucleus pollen grain of cytoplasmic male-sterile line in Brassica napus Var. oleifera(Raphanus sativus L. ).
空囊产生的主要途径：①四分体至单核早期绒毡层细胞体积发生明显的增大、液化；
The main pathways of causing empty anther sacs are obvious enlargement and liquidization of tapetum cells from tetrad to slope nucleus early period;
当花萼包住花瓣、萼长于瓣、花药白绿色时，多数小孢子处于四分体时期或单核早期；
When the calyx is encased by petal, the calyx is longer than the petal, and the anther is greenish white, most of the microspore is at the earlynucleate stage.
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.
此外，观察了前期I的簇毛麦染色体形态，统计了四分体和小孢子中小麦和簇毛麦染色质微核频率。
Otherwise, the chromosome morphology involving Haynaldia chromatin was observed at preleptotene I, and the frequencies of chromatin nucleus at tetrad stage and at microspore stage were investigated.
大胞子四分体线形排列，合点端大孢子为功能大孢子，胚囊发育类型为蓼型，具有特化的珠被绒毡层和承珠盘。
Megaspore tetrad is linear. the chalazal megaspore develops into an embryo sac of polygonum type. Hypostase and special integument tapetum exist in the ovule.
单瓣紫花木槿的小孢子母细胞经过减数分裂形成四面体状的四分体，成熟花粉是二细胞型花粉，圆球型，表面有刺毛。
The results showed that the type of microsporic tetrads of the simple flower is belong to tetrahedral type and the mature pollen is two-celled with bristles on the surface.
单瓣紫花木槿的小孢子母细胞经过减数分裂形成四面体状的四分体，成熟花粉是二细胞型花粉，圆球型，表面有刺毛。
The results showed that the type of microsporic tetrads of the simple flower is belong to tetrahedral type and the mature pollen is two-celled with bristles on the surface.
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