筛管细胞

电子显微镜观察发现，在病株嫩枝和叶柄韧皮部筛管细胞超薄切片中，存在着大量的类菌原体（MLO）。

A lot of mycoplasma-like organisms ( MLO ) were observed within the ultrathin sections of sieve cells in the infected tender shoots or phloem tissues with electron microscopy .

在电子显微镜诊断中发现有MLOs靠近寄主筛管细胞的细胞壁和穿进寄主细胞壁的现象。

Through the electronic microscope , the cells of the pathogen ( MLOs ) arefound penetrating the sieve tube 's cellular wall .

细胞质细丝即胞间连丝通过这些侧壁上的穿孔而延伸，以连接并列的筛管细胞。

Fine strands of cytoplasm , the plasmodesmata , extend through these pores , connecting sieve-tube cells that lie side by side .

子叶维管束发育成熟约在受精后的20d，成熟时细胞核消失，次生壁向内延伸，筛管分子的细胞壁形成网纹结构。

Developing mature of vascular bundle about 20 days after fertilization . The cells nucleus disappear in this period , secondary wall extended toward the inside . Sieve element formed network .

另一类是位于纺锤体两端、形态介于线条形细胞和正常筛管分子之间的细胞，此类细胞两端的端壁形态不同。

The other type of cells located at both ends of the spindle which possess an intermediate form between the filiform cell and the normal sieve tube .

维管形成层韧皮部母细胞分裂分化形成筛管、伴胞、韧皮薄壁细胞、韧皮纤维和少量的石细胞，筛管和伴胞来源于筛管母细胞的不均等有丝分裂。

The secondary phloem mother cell were divided and differentiated into sieve tube , companion cell , libriform fibre , parenchyma cell , and a few sclereid cells , The sieve tube and companion cell was originated from inequality mitosis of sieve mother cell .