【作者】 杨旭；

【导师】 秦广雍； 代西梅；

【作者基本信息】 郑州大学 ， 生物物理， 2010， 硕士

【摘要】 本项研究以二倍体和四倍体水稻为试验材料。对离子注入处理后所引起M1代及M2代水稻根尖细胞内染色体的畸变类型、畸变率,有丝分裂指数等细胞学特征及其对发芽率的影响进行了系统研究。另外,初步探究了水稻根尖细胞在分化过程中微丝网络的分布格局的变化。本实验的研究结果重要包括如下几个方面：1.低能氮离子注入引起M1代水稻品种的根尖细胞在有丝分裂中出现了不同类型的染色体畸变,如染色体桥,染色体小断片,落后染色体等。根尖细胞染色体的畸变率与氮离子的处理剂量之间并非呈现明显的变化趋势,而是呈现一定的随机性。低能氮离子注入对某些水稻品种根尖细胞的有丝分裂具有促进作用,M1代根尖细胞有丝分裂指数升高。某些注入剂量对M1代水稻品系根尖细胞的有丝分裂具有促进作用,而某些剂量却抑制了根尖细胞的有丝分裂。2.低能氮离子注入对M2代水稻品种的根尖细胞的有丝分裂也具有促进作用,还可以引起M2代根尖细胞的染色体的畸变,其主要的畸变类型有染色体桥,染色体小断片,落后染色体等。这与M1代根尖细胞染色体的畸变类型相似,说明经离子注入处理后的染色体畸变具有一定的遗传性。但染色体在传代过程中也具有一定的修复作用,表现在M2代根尖细胞染色体的畸变率明显低于M1代。3.经低能氮离子处理后的水稻干种子种植于试验田中观察其减数分裂的情况发现在M1代水稻的花粉母细胞中的染色体出现了染色体桥,染色体小断片,落后染色体等类似于有丝分裂的畸变类型。并且还可见游离的染色体和染色体提前分离等特殊现象。4.初步研究了水稻根尖细胞分化过程中微丝分布格局的变化。发现水稻根尖细胞分化过程中从分生区至成熟区细胞内的微丝分布格局确实发生了改变。分生区细胞根据细胞所在的分裂时期主要有两种状态的微丝分布。间期细胞中无明显的微丝网络,整个细胞被激发出均匀、明亮的绿色荧光,细胞核清晰可见。分裂期的细胞细胞核区周围有大量的明亮的荧光呈“笼”状分布,细胞质中可见荧光较细胞核周围弱,并且微丝成束的出现,微丝束较多,在细胞膜周缘荧光较亮,表明细胞膜周缘中微丝分布密集。伸长区细胞,细胞核周缘有明显的微丝束向四处呈现辐射状分布,从不同层面的扫描结果可见在核周围多个层次上看到一些纤索的明亮的绿色荧光。成熟区细胞,细胞核周围有较强的荧光,而细胞质中几乎见不到荧光。更多还原

【Abstract】 The damage of the root tip cell chromosomes, including the rate of distortion, the type of aberration and the mitotic index etc. of the Ml and M2 generations coused by low energy ion implantation was studied in this paper, using diploid and tetraploid rice as materials. In addition, the distribution pattern of microfilaments network of the rice root tip cells during differentiation are preliminary researched. The results of this study was as follows.1. Implantation of low energy N+ ion beam can cause different types of chromosomal aberrations of the M1 root tip cells in mitosis, such as chromosome bridge, chromosome small fragments, laggards, etc. Chromosome aberration rate in root-tip cells is not proportional to N+ ion treatment dosages. but showes some randomness. Low energy N+ ion beam Implantation on some rice varieties mitotic of root tip cells could promote the mitotic index of Ml generation root tip cells increased. Some injected dose can promote mitosis of M1 generation rice strains root-tip cells, and some doses inhibited mitosis of root tip cells.2. Low energy N+ion beam implantation on M2 generation rice varieties mitotic of root tip cells also could promote, and lead to M2 generation root tip cells of the chromosome aberration, the main types of distortion, chromosome bridge, chromosome small fragments, laggards, etc. M2 with Ml generation root tip cells of chromosome aberration of a similar type. M2 generation of root tip cell chromosome aberration rate lower than the M1.3. Seeds of rice treated by low energy N+ion were planted at rice experimental field of Institute of Rice Science, Xinxiang Agricutural Technology Research Academy. The meiosis of pollen mother cells in M1 generation were observed. The result showed that the chromosomal aberrations were similar to the type of mitotic aberration, appearing chromosome bridge, small chromosomal fragments, lagging chromosomes. Besides that, the free chromosomes, chromosome separation and other special phenomenon ahead of schedule were found.4. The distribution pattern of microfilaments network of the rice root tip cells during differentiation are preliminary researched. It was found that the actin distribution pattern in rice root tip cells during differentiation from meristematic zone to the mature region were significant different. There were two states of actin distribution in the meristem region. In interphase cells, There were no obvious microfilament network, the cell was inspired by the uniform, bright green fluorescence, and the nucleus is clearly visible. In mitotic phase cells, nucleus were surrounded by a large number of bright fluorescence, Showed a "cage"-like distribution. There were a large number of fluorescent nuclei peripheral radial distribution of the four presented in elongation region cells. The nucleus were surrounded by bright fluorescence, while almost no fluorescence in cytoplasm in mature zone cells.更多还原