摘    要 铝（Al）离子毒害是酸性土壤中抑制作物生长发育及其产量的主要因子，大麦是对Al离子的毒害最为敏感的作物之一。一氧化氮（NO）作为植物体内的一种活性信号因子，参与了植物对各种胁迫的应答。为了探讨外源NO对Al胁迫下大麦幼苗根生理生化及分子机制的影响，本研究采用营养液水培法，加入不同浓度的SNP，检测大麦幼苗根中超氧化物歧化酶（SOD）和过氧化物酶（POD）活性，过氧化氢（H2O2）和丙二醛（MDA）含量及DNA模板变化，来了解外源NO对Al胁迫大麦幼苗的影响。结果表明，尽管存在一定的基因型差异，但外源NO能使两种大麦幼苗中的SOD和POD活性下降，降低叶片中H2O2和MDA含量，维持较高的基因组模板稳定性（GTS），从而缓解Al对大麦幼苗的毒害。90378

Abstract Aluminum (Al) toxicity is the principal factor that restricts the growth and yield of crops in acid soils, while barley is one of the most sensitive crops to Al poison。 Nitric oxide (NO) is a bioactive gas and is an important signaling molecule in plant, involving the response to various stress。 In order to understand the regulative effect of exogenous nitric oxide on the physiological and biochemical responses, and the effects of molecular mechanisms in barley seedlings under aluminum stress, in the present study, two barley cultivars grown in IRRI’s nutrient solution were used to investigate the effects of exogenous nitric oxide (sodium nitroprusside as NO donor) (0, 50, 100, 200, and 300μM) on the growth of seedlings under aluminum stress, activities of antioxidant enzymes (SOD and POD), the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) , and changes in the DNA template。 The results show that exogenous SNP significantly decreased the activities of superoxide dismutase (SOD) and peroxidase (POD), reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and made genomic template stability (GTS) maintained at a high level in the roots of barley seedlings under aluminum stress, though certain genotype difference。 It suggested that SNP could alleviate the damage of barley seedlings caused by aluminum。 

毕业论文关键词：大麦幼苗； Al胁迫； SNP； 过氧化酶系统； GTS

Keywords: Barley seedlings; aluminum; SNP; Peroxidase system; GTS

目    录

引  言 4

1 材料和方法 5

1。1 实验材料处理 5

1。2 相对根伸长量的测量 6

1。3大麦生理生化指标测定 6

1。3。1粗酶提取液的制取 6

1。3。2超氧化物歧化酶（SOD）活性 6

1。3。3过氧化物酶（POD）活性 6

1。3。4过氧化氢（H2O2）含量 6

1。3。5丙二醛（MDA）含量 7

1。4 DNA提取和SRAP过程 7

1。5 基因组模板稳定性估计(GTS) 8

2 结果与分析 8

2。1 筛选合适AL浓度 8

2。2 外源NO对AL胁迫下大麦幼苗根长的影响 9

2。3 AL胁迫下外源NO对抗氧化酶系统活性的影响 9

2。4 AL胁迫下外源NO对MDA和H2O2含量的影响 9

2。5AL胁迫下外源NO对基因组多态性的影响 10