Abstract:

In order to investigate the changes of seedling growth, leaf physiology and leaf cell morphology and structure of Medicago sativa L.×Meliloides ruthenica (L.) Sojak. ‘Longmu 806’ dry seed were irradiated with different doses of ⁶⁰Co-γ radiated. The results showed that radiation had different effects on the growth, leaf physiology and leaf cell morphology of Medicago sativa L.×Meliloides ruthenica (L.) Sojak. ‘Longmu 806’ seedlings. With the increase of radiation dose, Plant height and root/shoot ratio of seedlings increased first and then decreased. The change of taproot length and biomass decreased. 1 200~1 500 Gy radiation doses had a stronger inhibitory effect on seedling growth. After radiation, soluble protein, soluble sugar and proline content increased first and then decreased. The content of malondialdehyde and relative electrical conductivity increased with the increase in radiation dose. The effect of 600~900 Gy radiations on leaf cell and chloroplast morphology was relatively small. When the radiation dose was 1 200~1 500 Gy, the cell morphology of leaves showed obvious deformation, vacuolization and plasmolysis, and thylakoid were severely deformed, the number of starch granules was large and the number of was large butthe number of mitochondria showed a significant decrease.

Key words: Medicago sativaL.×Meliloides ruthenica(L.) Sojak. ‘Longmu 806’, ⁶⁰Co-&gamma, radiation, Growth and physiology, Cell morphology structure

摘要：

为了探究⁶⁰Co-γ辐射‘龙牧806’苜蓿干种子的幼苗生长、叶片生理和叶片细胞形态结构的变化，试验采用不同剂量⁶⁰Co-γ辐射剂量对苜蓿种子进行辐射处理。结果表明：辐射对苜蓿幼苗的生长、叶片生理和叶片细胞形态结构产生不同程度的影响。随着辐射剂量的增加，株高和根冠比均呈现先增加后降低的变化趋势，主根长度和生物量出现降低的变化趋势，1 200～1 500 Gy辐射剂量下对幼苗的生长抑制作用更强。辐射后的叶片可溶性蛋白、可溶性糖和脯氨酸含量呈现先增加后降低的变化趋势，丙二醛含量和相对电导率随辐射剂量增加出现增加的变化趋势。600～900 Gy辐射后叶片细胞和叶绿体形态结构的影响比较小，而辐射剂量为1 200～1 500 Gy叶片细胞形态出现明显变形、空泡和质壁分离现象，叶绿体形态和类囊体变形严重，淀粉粒数量多和个体大，线粒体数量明显减少。

关键词: &lsquo, 龙牧806&rsquo, 苜蓿, ⁶⁰Co-&gamma, 辐照, 生长和生理, 细胞形态结构