【作者】 叶武威；

【导师】 喻树迅；

【作者基本信息】 中国农业科学院 ， 作物遗传育种， 2007， 博士

【摘要】 针对我国盐碱地面积大、分布广、危害重、影响大的特点，利用60份种质(系)研究了耐盐性骨干品种的血缘组成和耐盐性的主要相关因子，利用不同耐盐性的材料探讨了盐胁迫对棉花生理代谢的影响，并进一步研究了耐盐基因的表达。获得了以下的结果：1．明确了棉花耐盐骨干品种的基础种质及其亲源关系。耐盐骨干品种主要来自于岱字棉、乌干达棉、金字棉、苏联棉系四个基础种质，耐盐材料中88.33％含有岱字棉血统，81.67％含有乌干达棉血统，78.33％含有金字棉血统，65％含有苏联棉血统。当前，我国陆地棉种质耐盐性较低的主要原因应归结于基础种质耐盐性差和耐盐种质的血缘过于狭窄。2．研究了棉花耐盐性与主要遗传性状的相关关系。棉花耐盐性与铃重呈极显著正相关；耐盐性与种仁蛋白质含量呈显著负相关，与种仁脂肪含量达极显著正相关；耐盐性与纤维长度呈极显著正相关，与麦克隆值呈极显著的负相关，所以NaCl有利于棉花纤维细胞的增长而不是增粗。棉花的耐盐性与抗旱性达极显著正相关，说明了耐盐性的渗调机理与抗旱性的作用机理相似。3．探讨了盐胁迫对棉花有丝分裂过程中的染色体行为的影响。盐胁迫对棉花的细胞分裂指数有着正负两个方面的效应，低浓度下的促进作用和高浓度下的抑制作用，而且促进作用和抑制作用均与耐盐性有关。盐胁迫造成染色体的畸变如C-有丝分裂、染色体桥、染色体粘连、染色体消解等特异现象，而且随着浓度与培养时间的延长，染色体变异越重；棉花耐盐性差则染色体变异重，这是NaCl胁迫后首次发现的离子毒害的证据。4．研究了盐胁迫对POD、SOD以及诱导蛋白的影响。棉花的耐盐性与叶片膜透性负相关。棉花叶片SOD、POD活性都随着NaCl浓度的增加而提高，但是耐盐品种SOD活性的上升速度明显快于不耐盐品种，耐盐材料POD活性的上升速度明显慢于不耐盐材料，这种变化与材料的耐盐性高低相反。盐胁迫后，蛋白质含量均降低，但有新增的蛋白质谱带，不耐盐材料新增加80kD、36kD、26kD、24kD四条谱带，耐盐材料新增加80kD、36kD两条谱带。24kD和36kD蛋白与耐盐性表达有关，26kD蛋白与耐盐性有关的调渗蛋白类似。80kD蛋白属首次发现。5．研究了盐胁迫下棉花耐盐相关基因的差异表达。在盐胁迫下，不耐盐的材料有1644个基因差异表达，耐盐材料有817个基因差异表达。棉花耐盐性基因依表达量可分为5类：A类基因32个，只在耐盐材料差异性表达的上调基因；B类基因548个，只在不耐盐材料差异性表达的上调基因；C类基因176个，只在耐盐材料差异表达的下调基因；D类基因487个，只在不耐盐材料差异表达的下调基因；E类基因609个，不耐盐材料和耐盐材料均差异性表达的下调基因。棉花耐盐基因依表达蛋白的已知功能可分为4类：(1)渗透调节蛋白表达基因96个；(2)毒性降解酶基因48个；(3)转录因子基因136个；(4)信号传导基因98个。更多还原

【Abstract】 Salinity resistance and differential gene expression associated with salinity in cotton germplasm were studied, according to the large scale of saline area in China and its negative significant effects on the cotton production. The pedigree and correlation coefficients between agronomic traits and the salinity tolerance were analyzed from 60 salinity tolerant cotton genetypes. The tolerance and its biochemical effects on the main genetic characters, the resistance genes and their differential expression were studied by the salinity-tolerant and salinity-sensitive cotton genetypes. The following were the results:1. The basic germplasm and its pedigree were explicitly clarified. The genealogy of 60 cotton salinity-tolerant genetypes was clustered into four basic germplasms such as Deltapine, King,Uganda and Russia, whose descents were contributed to the most of the salinity-tolerant cotton varieties. According to the genealogy proportions, there were 88.33% of Deltapine, 81.67% of Uganda,78.33%of King, and 65% of Russia in all of the 60 salinity-tolerant cotton varieties. All the main cotton varieties, nowadays, at the much lower level of salinity-resistance, are due to the two reasons. The one is the much lower level of salinity-resistance of the basic germplasm, and another is that the basic germplasms are extremely too centralized to broaden the background of the salinity-resisted cotton varieties.2. The correlations of the salinity resistance with the main genetic characters were analyzed. The salinity resistance positively correlated with the boll weight outside of the main cotton agronomic characters under the stress of NaCl. As to the relationships between the salinity resistance and the seed quality, the salinity resistance negatively correlated significantly with the protein proportions and positively correlated significantly with fat of the cotton seed embryo. There were remarkable relationships between the salinity resistance and the fiber quality. The salinity resistance positively correlated significantly with the fiber length and negatively correlated significantly with the fiber micronaire, which indicated that salt stress could enhance the elongation and inhibited the thickness of the fiber. The results also indicated that there were positive correlation between the salinity resistance and the draught resistance, which showed that the mechanism of salinity resistance was similar to that of the draught resistance.3. The effects of salinity stress on the cell division and chromosome behavior were first observed on cotton. It could be obviously observed that there were negative, at the lower(0.1%-0.2%) NaCl, or positive, at the higher concentration (0.3%-0.5%) of NaCl, effects on the mitosis index of the cotton seedling, The effects of NaCl changed with the resistance level of the varieties. The abnormal chromosome behavior such as C-mitosis, Chromosome bridge, Chromosome stickiness, Chromosome melting had been observed and first studied in detail on cotton. All the abnormal behaviors fluctuated with the salinity resistance of cotton and the concentration of NaCl.4. Metabolism changes of total protein, soluble sugar, and physiological characters of SOD(superoxide dismutase) ,POD(perioxidase) activity under the NaCl stress were studied. There were negatively correlation between the salinity resistance and the leaf membrance injury. POD and SOD activities changed higher as the NaCl changed to higher concentrations, but SOD activity of the salinity-resisted cotton fluctuated quickly than the salinity-sensitive cotton, and it was on the reverse of the POD. The protein proportions reduced significantly as the NaCl concentrations got to higher with the novel proteins such as 80kD, 36kD, 26kD, 24kD of the salinity-sensitive cotton. The results showed that there were 80kD and 36kD proteins of the salinity-resisted cotton under the stress of NaCl. The results also showed that 24kD, 36kD were correlated with the salt resistance of plants and 26kD was similar to the osmotin. 80kD was the first found protein as to the mechanism of the cotton salinity resistance.5. The salinity-resisted genes and their differential expression were studied under the stress of NaCl on cotton. There found, under the NaCl stress, 1644 genes differentially expressed from the salinity-sensitive cotton and only 817genes differentially expressed from the salinity-resisted cotton. The differential expressed genes could be divided into five groups according to the expressed levels by the cluster analysis. A goup:32 up-conditioned genes, differentially expressed only in the salinity-resisted cotton; B group, 548 up-conditioned genes, differentially expressed only in the salinity-sensitive cotton; C group, 176 down-conditioned genes, differentially expressed only in the salinity-resisted cotton; D group, 487 up-conditioned genes, differentially expressed only in the salinity-sensitive cotton; E group, 609 down-conditioned genes, differentially expressed both in the salinity-sensitive and salinity-sensitive cotton. The salinity-resisted differentially genes could also divided into 4 groups according to the known functions of the expressed protein: 96 osmotin genes, 48 toxicity-reduced genes, 136 transcription factors, and 98 signal transmitted genes.更多还原