【作者】 郑霞；

【导师】 季良越；

【作者基本信息】 河南农业大学 ， 作物遗传育种学， 2003， 硕士

【摘要】 玉米是一种主要农作物，同时是盐敏感作物，提高玉米的耐盐性，培育玉米耐盐品种具有重要的意义。本试验利用玉米幼胚作为外植体诱导愈伤组织，并以NaCl为筛选剂，采用多步选择法，先在含1.0％-1.5％-2.0％NaCl的筛选培养基上连续筛选三次，然后转入无盐培养基上培养三代，得到耐盐愈伤组织变异系。分化出的R₀代再生植株，经温室缓苗后移栽到大田，于开花期自交授粉得到R₁代种子。测定不同浓度盐胁迫下愈伤组织相对生长量、干物质累积、游离脯氨酸含量和Na⁺、K⁺含量，并测定1.0％NaCl胁迫下R₀代再生株叶片的可溶性糖和相对电导率以及不同浓度盐胁迫下R₁代种子的发芽率、R₁代幼苗的株高、根条数、主根长和游离脯氨酸含量等与耐盐性相关的指标，结果如下： 1)随着盐胁迫强度的增加，对照和耐盐变异系的相对生长量下降，但同样胁迫下变异系的相对生长量仍高于对照，变异系干物质的积累大于对照；随着NaCl浓度的升高，对照和变异体的脯氨酸含量均增加，且变异体脯氨酸含量的增幅大于对照；对照和耐盐愈伤组织变异体细胞内Na⁺含量在0-1.0％的NaCl浓度范围内随NaCl浓度的升高急剧增加，当NaCl浓度继续增加时，对照细胞内Na⁺含量明显降低，而耐盐愈伤组织变异体细胞内仍维持相当高的Na⁺水平。 2)在相同的盐胁迫下耐盐变异体R₀植株叶片的相对电导率低于对照，可溶性糖含量和脯氨酸含量高于对照，愈伤组织水平的高脯氨酸特性在R₀代再生植株得以保持，表明变异系的R₀代再生植株是耐盐的。玉米种子发芽对盐极其敏感，随着盐浓度的增加，R₁代种子发芽率下降，但对照发芽率下降幅度大于耐盐变异体R₁种子，变异系R₁代种子在0.4--2.0％NaCl浓度培养基中的发芽率均高于对照，变异系与对照的苗高、根的条数和主根长随着盐浓度的增加都呈下降趋势，然而相同盐浓度下变异系上述三项指标均高于对照。R₁代 2000级硕＿．L研究生毕业论文再生植株叶片脯氨酸含量较愈伤组织和巳；代再生植株明显降低，尽管R；代再生植株游离脯氨酸绝对含量下降，但变异系仍比对照系高，说明变异系积累脯氨酸的能力强于对照。由此看来我们得到的耐盐变异体的R；代种子确实是耐盐的，R；代幼苗也具有较强的耐盐性，表明耐盐变异体的耐盐性是可以遗传的，筛选是有效的。更多还原

【Abstract】 Maize is important crop, and it is sensitive to salinity. In our country,amount of plough are salines. To improve the adaptive of maize to salinity, breeding new NaCl-tolerant varieties of Maize is urgent. An project on selecting salt-resistant Maize was put on in our lab. The calli were induced from the immature embroys of maize. After the calli were propagated,they were subgenerated in the N6 medium containing NaCl for three times to select NaCl-tolerant variants. The content of NaCl was increased from 1.0%-1.5%-2.0% one by one, then the NaCl-tolerant variants were transferred to NaCl-free medium for three times subgeneration. The relative growth rate of calli ,the content of proline , the ratio of dry material and waterish weight were analysised.The results showed that when increasing NaCl concentration ,the relative growth rate decreased, the proportion of dry weight to fresh weight, the content of pro rised. While suffering the same salt stress, the varietants accaculate more pro and grew more quickly than the control. It proved the calli were NaCl-tolerant indeed. RO plants were regenerated from NaCl-tolerant callus variants and RI seeds were obtained. The relative electronic conductivity of leaves of the RO variant was lower than the control, but solution sugar content was higher than the control under 1.0%NaCl stress. The germinating rate of R1 generation seeds, the variants were higher than the control, especially the germinating rate of the variant was 20% under 1.6% NaCl pressure, but that of control was zero. In Comparing of the control under the same NaCl stress, the variants seedling had more roots, their seedling were higher. The pro content of the calli and RO plantlet were ten times higher than that of R1 plantlet. However the pro content of the Variants were always higher than that of control. All of the indexes showed that the calli variants and their regenerated plants aresalt-tolerant, and the character of salt-tolerant was inheritable.更多还原