转Bt基因抗虫棉和有色棉苗期耐盐性差异研究

盐胁迫可致棉叶萎焉 ,叶温升高 ,气孔导度、蒸腾强度和光合速率降低 ,促进膜脂过氧化、丙二醛 (MDA)积累。但棉株体通过保护酶活性的提高和协同作用 ,以及盐离子的区域化分布 ,表现出较强耐盐胁迫的能力。耐盐性因基因型而异 ,在供试材料中 ,棕色棉和绿色棉的耐盐性最强 ,转 Bt基因抗虫棉 3 3 B和 S6 1 77的耐盐性最差。基因型间耐盐性差异与保护酶活性和盐离子在叶片中积累量的差异有关。长期人为选择可致棉花抗逆性的部分丢失 ,Bt基因的导入也可能影响棉花耐盐性的表达。

A Comparative Study on Salt Tolerance between Bt Transgenic Cotton and Naturally Coloured Cotton during Seedling Stage

Salt stress could cause such damages to cotton (Gossypium hirsutum L.) plant as the leaf wilt, leaf temperature increased,decreased in the stomata conductance, the transpiration rate and the net photosynthetic rate, and the accumulation of MDA as a result of the peroxidation of the fatty acid in cell membrane. Under the salt stress, however, considerate tolerance was induced in cotton plant due to the increase in POD activity and the compartmentation of the ion. The salt tolerance of the cotton varied in genotypes. Among the tested cotton genotypes, the brown cotton and the green cotton had the highest tolerance to the salt, while the two transgenic cotton varieties had the lowest, which was closely related to the difference of POD activity and the accumulation of the ion in leaves. It was predicted that the long term selection in cotton breeding could cause partial losses of resistance and the transformed Bt gene might affect the expression of the salt tolerance in the cotton plant.