60Co-辐照对三七叶片组织结构和细胞形态结构的影响

采用剂量分别为0、10、20、40 Gy的60Co-射线对三七种子进行辐照处理,利用透射电子显微镜观察研究其对三七叶片组织结构和细胞形态结构的影响,旨在为三七辐照育种提供理论参考.电镜观察结果表明:60Co-射线辐照对三七叶片组织结构和细胞形态结构产生不同程度的影响和损伤,且各结构变化不同步.与0 Gy相比,当辐照剂量为10 Gy时,三七叶片栅栏组织细胞由1层变成2层,细胞排列宽松;细胞形态畸变,线粒体数量略微增加,细胞核、细胞壁结构受损,细胞出现质壁分离现象.当辐照剂量为20 Gy时,海绵组织细胞形状不规则程度增加,细胞排列更为松散,细胞内叶绿体、线粒体、细胞核、细胞壁受损伤较大,细胞质壁分离现象严重.当辐照剂量达到40 Gy时,海绵组织和栅栏组织结构受影响程度最大,细胞排列极为疏松,层次结构不清晰,叶绿体、线粒体数量均显著减少,质壁分离最为严重,三七叶片正常生长发育受阻.可见,60Co-射线辐照对三七叶片组织结构的影响和对细胞形态结构的损伤程度随辐照剂量的增加呈增大趋势;海绵组织对60Co-射线辐照的耐受性比栅栏组织强;其次是叶绿体和线粒体,且适当的辐照可增加线粒体数量;细胞核对辐照较敏感.以上结论可以为不同目的的三七育种提供理论依据,并为选择最适辐照诱变育种剂量提供理论参考.

Effect of 60Co- Irradiation on Tissue Structure and Cellular Morphological Structure of Panax notoginseng Leaves

The seeds of Panax notoginseng were irradiated with 0, 10,20, and 40 Gy 60Co- irradiation, respectively. The effects of 60Co- irradiation on tissue structure and cellular morphological structure of P. notoginseng leaves were observed and studied by transmission electron microscope (TEM), which provided a theoretical reference for P. notoginseg irradition breeding.The results of the electron microscope observation showed that there were varying degrees of impact and damage on the tissue structure and cellular morphological structure of P. notoginseng leaves by 60Co- irradiation and different structural changes were not synchronious. Compared with 0 Gy irradiation treatment,when the irradiation dose was 10 Gy, palisade tissue cells became two layers and cells arranged loosely;cell shapes distorted, the number of mitochondria increased slightly, nucleus and cell walls were damaged and cells appeared plasmolysis phenomenon. When the irradiation dose was 20 Gy,the irregular degree of spongy tissue cell shapes increased, cells arranged more loosely. The degree of damage of chloroplast,mitochondrion, nucleus and cell wall in cells was bigger and the plasmolysis became more serious. When the irradiation dose was 40 Gy, spongy tissue and palisade tissue were most affected, cell arrangement was extremely loose and the hierarchy was not clear. The amount of chloroplasts and mitochondria decreased significantly, the plasmolysis was most serious and the normal growth and development of P. notoginseng leaves was blocked. It might be concluded that the effect on the tissue structure and the damage degree of cellular morphological structure of P. notoginseng leaves tended to increase with increasing irradiation dose.The spongy tissue had better tolerance to 60Co- irradiation than palisade tissue, followed by chloroplasts and mitochondrial, and the proper radiation could increase the number of mitochondria;the nucleus was more sensitive to radiation.The above conclusions could provide theoretical basis for P.notoginseng breeding of different purposes and provide theoretical reference for choosing the most appropriate dose of irradiation mutation breeding.