水稻镉积累特性的遗传差异及其稳定性分析

发布时间：2018-05-18 15:53

本文选题：水稻 + 镉(Cd)　；参考：《河南农业大学》2016年硕士论文

【摘要】：随着现代工农业生产的快速发展,工业“三废”排放量的日益增加,农田镉(Cd)污染面积不断扩大,使得稻米Cd安全问题日趋严重。筛选和培育低Cd积累品种,是解决中轻度污染区粮食安全生产的行之有效的方法。研究水稻对Cd的吸收、转运及积累特征及其耐Cd机理,将为低Cd积累品种的选育、控制稻米Cd积累提供重要的理论依据。本研究以水稻核心种质资源和当前主推水稻品种为材料,结合室内试验和田间试验,对Cd积累特性的基因型差异及其稳定性进行了分析;对水稻幼苗中Cd的亚细胞分布和非蛋白巯基含量进行了比较研究;与此同时,探索了幼苗根系Cd积累能力、幼苗Cd转运能力、离体叶片耐Cd能力与稻米Cd积累特性的关系。主要结果如下:1、基因型间的遗传多样性主要表现在根系对Cd的最大吸收速率F_(max)和向地上部的转运效率上。水稻根系对Cd积累动力学特征全部符合米氏方程,根系F_(max)值小于50.8 nmol·g~(-1)(DW)·h~(-1)的13份基因型,其地上部Cd积累动力学特征符合线性方程,Cd转运效率随着环境中Cd浓度的增加而持续升高;根系的F_(max)值大于55.5 nmol·g~(-1)(DW)·h~(-1)的基因型,其地上部的Cd积累动力学特征也符合米氏方程,它们的Cd转运效率随着环境中Cd浓度的增加而先升高后降低。2、对不同Cd胁迫环境中水稻幼苗根系和地上部Cd积累量的稳定性进行分析,发现基因型、环境及二者的交互作用对Cd积累量均有显著影响,其中‘齐头白谷’、‘广两优1128’为Cd积累量高且稳定性好的品种;‘麻麻谷’、‘特青选恢’、‘27760’为Cd含量低且稳定性好的品种。3、根系细胞壁和原生质体的Cd吸收动力学特征也都符合米氏方程,‘齐头白谷’的Cd最大吸收速率F_(max)显著大于‘27760’,Km值在两品种间无显著差异。地上部细胞壁和原生质体的Cd吸收速率与根系可溶性组分中的Cd浓度呈显著的线性正相关。当根系可溶性组分中的Cd浓度相近时,‘齐头白谷’地上部细胞壁和原生质体的Cd积累速率显著高于‘27760’。根系可溶性组分中的Cd是地上部Cd吸收的直接来源。4、水稻幼苗根系吸收的Cd主要分布在细胞壁组分,其次为胞液,在细胞器中的分布最少。Cd在地上部的分布顺序为细胞壁胞液细胞器。细胞壁和胞液中的Cd分配比例在品种间无显著差异,但在细胞器中,‘27760’所占的比例明显低于‘齐头白谷’。无论根系还是地上部,‘27760’的非蛋白巯基(Cys、GSH、PC2和PC3)含量均高于‘齐头白谷’,其中PC2和PC3主要存在于根部,地上部以GSH和Cys为主。5、当外界Cd浓度为0.89~8.9μmol·L~(-1)时,随着Cd浓度的增加,‘齐头白谷’离体叶片的失绿速度明显低于‘27760’。水稻离体叶片的耐Cd能力和幼苗根系的Cd积累能力以及幼苗的Cd转运能力高度相关,可作为快速鉴定低镉积累品种的生理指标。6、在Cd含量为1.782 mg·kg~(-1)、pH 5.2的土壤中进行田间试验,稻米Cd超标率高达98.7%;其中稻米Cd最高含量为2.049 mg·kg~(-1),最低为0.197 mg·kg~(-1)。对幼苗Cd吸收特性、离体叶片失绿速率及田间试验结果进行综合分析,发现‘山酒谷’和‘桂花黄’为Cd敏感型低Cd积累品种,‘齐头白谷’和‘粳7623’为耐Cd型高Cd积累品种。
[Abstract]:With the rapid development of modern industrial and agricultural production and the increasing amount of industrial "three wastes", the area of cadmium (Cd) pollution in farmland is expanding continuously, which makes the problem of Cd safety in rice becoming more and more serious. It is an effective method to select and cultivate low Cd accumulative varieties, which is an effective method to solve the food safety in the medium and mild polluted areas. The study of the absorption and transport of rice to Cd The characteristics of accumulation and its Cd resistance mechanism will provide an important theoretical basis for the selection of low Cd accumulative varieties and the control of rice Cd accumulation. In this study, the genotypic differences and stability of the accumulation characteristics of Cd were analyzed with the core germplasm resources of rice and the current main varieties of rice, and the genetic diversity and stability of the accumulation characteristics of the rice were analyzed. The subcellular distribution of Cd and the content of non protein sulfhydryl group in the seedlings were compared. At the same time, the Cd accumulation ability of seedling roots, the Cd transport capacity of the seedlings and the relationship between the Cd ability of the leaves and the Cd accumulation characteristics of the rice were studied. The main results were as follows: 1, the genetic diversity among the genotypes was mainly manifested in the maximum absorption rate F_ (F_) to the root system (Cd). Max) and the transport efficiency to the upper part of the earth. The kinetic characteristics of Cd accumulation in rice roots were all in accordance with the Michaelis equation, and the F_ (max) values of the root system were less than 50.8 nmol. G~ (-1) (DW). H~ (-1) of the 13 genotypes. Ax) is more than 55.5 nmol. G~ (-1) (-1) (DW). H~ (-1) genotypes. The kinetic characteristics of the accumulation of Cd in the upper part of the ground also conform to the Michaelis equation. Their Cd transport efficiency increases with the increase of Cd concentration in the environment and then reduces.2. The stability of the accumulation of rice seedlings in the root system and the upper part of the ground in different Cd stress environments is analyzed and the gene is found. Type, environment and the interaction of the two have significant influence on the accumulation of Cd. Among them, "Qi head white Valley" and "Guang two you 1128" are high and stable varieties of Cd, and 'ma ma valley', 'special Qing Xuan Hui', '27760' are.3 with low Cd content and good stability, and the Cd absorption kinetics characteristics of root cell wall and protoplast are also characterized. The Cd maximum absorption rate F_ (max) was significantly greater than '27760', and there was no significant difference in Km value between two varieties. The Cd absorption rate of the cell wall and Protoplast in the upper part of the ground was significantly linearly correlated with the concentration of Cd in the soluble components of the root system. When the concentration of Cd in the root soluble components was similar, ' The Cd accumulation rate of the cell wall and Protoplast in the upper part of the root white valley was significantly higher than that of '27760'. The Cd in the soluble component of the root system was the direct source of.4 for the Cd absorption in the upper part of the ground. The Cd of the root absorption of the rice seedlings was mainly distributed in the cell wall components, followed by the cytoplasm, and the distribution of the least.Cd in the upper part of the organelle was fine. There was no significant difference in the proportion of Cd distribution in cell wall and cytoplasm, but in organelles, the proportion of '27760' was obviously lower than that of 'white valley'. The content of non protein sulfhydryl group (Cys, GSH, PC2 and PC3) of '27760' was higher than that of 'the white valley', and PC2 and PC3 were mainly stored in the root and the upper part of the cytoplasm. In the root, the upper part of the ground is GSH and Cys mainly.5. When the external Cd concentration is 0.89~8.9 mol. L~ (-1), with the increase of Cd concentration, the green speed of the leaves in the leaves of the "Qi head white Valley" is obviously lower than '27760'. The Cd ability of the leaves of the rice leaves and the Cd accumulation energy of the seedling roots and the Cd transport capacity of the seedlings are highly correlated, which can be used as fast as fast. The physiological index.6 of low cadmium accumulated varieties was identified, and the field experiment was conducted in the soil of Cd content of 1.782 mg. Kg~ (-1) and pH 5.2. The rice Cd exceeded the standard rate up to 98.7%, and the highest content of the rice Cd was 2.049 mg kg~ (-1), and the lowest was 0.197 mg. It was found that "mountain wine Valley" and "sweet scented osmanthus yellow" were Cd sensitive low Cd accumulation varieties, "Qi head white Valley" and "Jing 7623" were resistant to Cd type high Cd accumulation varieties.
【学位授予单位】：河南农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X56;S511

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