转CBF_1基因棉花的耐旱生理研究

以转CBF_1基因棉花及其野生型棉花为材料,设置轻度(900 mL)、中度(400 mL)、重度(300 mL)和对照(1 200mL)浇水处理的不同干旱胁迫和复水处理,考察各种处理后对盆栽植株不同部位叶片光合性能和离体叶片在暗处理条件下叶绿素含量的变化,以及在大田苗期、蕾期、花期、铃期断水胁迫对棉花产量的影响,为转基因抗旱棉花新品种的培育提供理论依据。结果表明:(1)在盆栽试验中,随着干旱胁迫时间的延长和复水3d处理,各浇水处理的转基因和野生型棉花叶片净光合速率(P_n)、原初光能转化效率(F_v/F_m)表现出先降低后增加的变化趋势,受到胁迫后对顶部叶片的影响比中部叶片大,且转基因棉花叶片保留数量显著高于野生型棉花;它们的离体叶片叶绿素a、叶绿素b的含量随着干旱胁迫时间的延长而逐渐下降,但转基因棉花的下降速率显著低于野生型棉花。(2)在田间试验的苗期、蕾期、花期、铃期干旱胁迫下,各干旱胁迫处理的转基因植株的皮棉产量、衣分、种子质量、株高均显著高于野生型棉花;转基因棉花的籽棉产量分别比正常灌溉处理降低了78.4%、55.1%、12.7%、8.3%,野生型棉花则分别降低了80.4%、55.4%、19.2%、14.4%,不同时期的水分胁迫严重影响了棉花籽棉产量,但是转基因棉花的籽棉产量显著高于野生型棉花。研究认为,在不同干旱胁迫条件下,转CBF_1基因棉花表现出优良的生长和生理优势,可提高棉花的耐旱性。

Drought-tolerant Physiology of CBF1 Transgenic Cotton

In this study,the effects of mild(900 mL),moderate(400 mL),severe(300 mL) and CK(1 200 mL) drought stress and rewatering on CBF₁ transgenic cotton (24C-1) and wild type (TH₁) by different sites of leaf photosynthetic parameter and chlorophyll content changes of vitro leaf in dark conditions,and field experiment at seedling stage,bud stage,flowering stage,the bell stage with water stress treatments on production.The results showed that:(1)From the drought stress with different times to re-water 3 d,the net photosynthetic rate(P_n) and maximal photochemical efficiency(F_v/F_m) showed a trend of increasing firstly,decreasing then.Leaf retain number were significantly higher than that of wild type plant,at the top of the leaves is greatly damage to compare middle leaves under drought stress;with the stress time extended that Chl a,Chl b contents decreased,the decreased rate were significantly higher than that of wild type plant.(2)For the date of field experiment compared with normal irrigation treatment water stress at the seedling stage,bud stage,flower stage,bell stage the lint yield,seed index,seed quality,plant height of cotton decreased significantly,transgenic and wild type of the seed cotton yield reduced by 78.4%,55.1%,12.7%,8.3% and 80.4%,55.4%,19.2%,14.4%,respectively.The cotton yields of different stages have been affected by the water stress.But transgenic cotton yields are still significantly higher than that of wild type.These results demonstrated that the CBF₁ gene expression enhanced the growth and development of the transgenic cotton plant,and indicated that the CBF₁ transgenic cotton could improve the drought resistance.