种子沙引发对转基因抗虫棉耐盐性的影响

 以转基因抗虫棉花品种中棉所41和浙905为材料，以其遗传背景品种中棉所23为对照，研究了种子沙引发处理对转基因抗虫棉品种在0%、1.0%和1.5% NaCl浓度下的萌发率、出土率和幼苗生长特性的影响。结果表明，沙引发处理对转基因抗虫棉品种在盐胁迫下的种子萌发和幼苗生长具有明显的效果，但对于非转基因棉品种的效果不明显。幼苗子叶、茎秆和根的超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性和丙二醛（MDA）含量测定结果表明，沙引发处理使棉花幼苗的子叶和根部维持了较高的SOD与POD活性，但显著减少幼苗体内MDA的积累，说明沙引发有助于促进棉花在逆境下幼苗生长发育和抗逆性的提高。

Effect of Sand Priming on the NaCl Tolerance of Seed of Transgenic Insect Resistant Cotton (Gossypium hirsutum L.)

The effect of seed priming with sand on the seed germination, seedling emergence, the characters of seeding growth and development of the transgenic insect resistant cotton stressed with different concentrations of NaCl was studied, using two extending transgenic insect resistant cotton cultivars, CCRI 41 and Z-905, as materials and their genetic background cultivar, CCRI 23, as check. The results indicated that it was harmful for the seed germination and field emergence of the upland cotton seeds when they were treated with different concentration of NaCl. The germination percentage and field emergence of the transgenic insect resistant cotton cultivars stressed by NaCl were much lower than those of their genetic background check. However, priming treatment with sand could alleviate the harm of the NaCl stress significantly. After the treatment of seed priming, the germination percentage and seedling emergence on the condition of NaCl stress were increased significantly, and the seed tolerance to the salt stress was enhanced greatly, especially for the transgenic insect resistant cotton cultivars. There were great differences in the effect of the seed priming treatments on the seed germination and field emergence, stressed by NaCl, between the transgenic insect resistant cotton and their genetic background one; and the formers, with weaker tolerance against NaCl stress, had a better effect than that of their genetic background one without exogenous insect resistant genes. The results of biochemical analysis showed that the activities of peroxidase (POD) and superoxide dismutase (SOD) in cotyledons and roots of cotton seedling increased significantly, but decreased dramatically for the content of malondialdehyde (MDA), when they were treated by seed priming with sand, comparing with the check. This experiment indicated that sand priming for cotton seed could enhance the salt tolerance of seedlings due to increasing the antioxidant enzyme activity and reducing the malondialdehyde (MDA) accumulating in the cotton seedlings, which suggested that sand priming may help to improve seedling establishment and enhance the ability of salt tolerance in cotton.