常规棉‘鄂抗8号’与美国转Bt基因棉DP410B苗期对钾素响应的差异

为了探讨不同钾水平下常规棉与转基因棉在农艺性状和钾效率方面的差异，通过营养液对常规棉‘鄂抗8号’（E8）和转Bt基因抗虫棉DP410B（转）进行了苗期培养，分别设低钾(K1，2 mg/L)与适钾(K2，20 mg/L)2个处理，对农艺性状、干物质积累与分配、钾含量和钾积累量等进行研究。结果表明，相同钾水平下，转基因棉叶片数和叶绿素含量均高于常规棉E8；转基因棉干物质较多地分配到根系，而E8较多的积累在叶片中；各器官的钾含量和全株钾积累量均表现为转基因棉DP410B大于常规棉E8；钾在各器官的分配也有差异，适钾时常规棉E8根、茎中积累的钾占总钾的比例均低于转基因棉，而叶片中积累的钾占总钾的比例高于转基因棉，低钾时2个品种各器官的分配比例相同。常规棉E8钾效率系数是转基因棉DP410B的1.31倍，E8的钾利用指数也较高，表现为：E8K1（1.77） > 转K1（1.19） > E8K2（0.43） > 转K2（0.33），说明常规棉E8较耐低钾胁迫，且具有较高的钾利用效率，但是其增长潜力（3.75）比转基因棉DP410B（4.41）小。

Different Responses of Conventional Cotton E8 and American Transgenic Bt Cotton ‘DP410B’ to Potassium at Seedling Stage

A solution experiment was conducted to compare the differences of the agronomic traits,dry matter and K accumulation and distribution in plant organs were studied between the transgenic Bt cotton‘DP410B’and the conventional cultivar‘E8’.The culture solution K ＋ concentration was set the low K（K1,2mg/L） and the appropriate K（K2,20 mg/L） conditions.Under the same K level,the leaf number and chlorophyll content of Bt-transgenic‘DP410B’were higher than conventional cotton‘E8’.Transgenic cotton had more dry matter allocated to roots,while‘E8’accumulated more in leaves.Potassium content of various organs and whole plant accumulation of potassium of Bt-transgenic‘DP410B’were greater than conventional‘E8’.The distribution of potassium was different;the accumulation of potassium in roots and stems of the conventional cotton‘E8’was lower than the transgenic cotton at K2,while the accumulation of potassium in leaves was higher.Under the low potassium,the distribution proportions in each organ of two varieties were the same.Potassium efficiency of the conventional cotton‘E8’was 1.31 times that of the transgenic cotton,and K utilization index was also higher.These results indicated that K-use-efficiency of the conventional cotton‘E8’was higher,more resistant to low potassium stress.However,the yield potential of the conventional cotton＇E8＇was little than the transgenic cotton.