中文摘要：

以水培方法研究钾对两种棉花基因型钾效率特征及其根系形态上的差异。结果表明,高效基因型103钾利用效率在低钾与适钾时分别为160.2gg-1和47.5gg-1,而低效基因型122为133.8gg-1和37.9gg-1;在低钾和适钾处理时,103叶片钾积累量占全株钾积累量的84.6%和62.6%,122分别是63.4%和56.0%。在不同钾处理下103根系各参数均高于122,低钾时103总根长和根总表面积分别增加46.2%和13.9%,122根系各参数则均下降。缺钾抑制了粗根的生长,103在低钾时粗根的总根长、根表面积和根体积分别降低了54.0%、62.8%和75.2%;122粗根各参数也有所降低。但低钾时103细根的总根长、根表面积和根体积增加了69.0%、77.0%和80.4%,分别是122的1.9、2.3和2.6倍。

英文摘要：

The objective of this study was to analyze K-efficiency and root morphology in two kinds of K-efficiency cotton genotypes. The results showed that K-efficiency of genotype 103 was 160.2 g g 1 and 47.5 g g 1 at low （4 mg L-1） and high （40 mg L-1） K levels while genotype 122 was 133.8 g g 1 and 37.9 g g 1. In addition, genotype103 had higher ability to transfer K to leaves than genotype 122. Under two K levels, Leaves K accumulation of genotype 103 was 84.6% and 62.6% of the whole plant, while that of genotype 122 was 63.4% and 56.0%. High K-efficiency genotype 103 had higher total root length, surface area and volume than low K-efficiency genotype 122 regardless of the K concentration treated. Especially when the concentration of K in the environment was low, genotype 103 still had better root system than genotype 122. When K was insufficient, the total root length and total root surface area of genotype 103 increased by 46.2% and 13.9%, while genotype 122 showed decreases in root parameters. Root system was classified into fine roots, middle roots and coarse roots according to root diameter. Low K condition limited the development of coarse roots. In genotype 103, coarse root length, surface area and root volume decreased by 54.0%, 62.8%, and 75.2%, respectively, meanwhile, genotype 122 also had a reducing coarse root parameters. Effect of low K condition on fine roots varied in different cotton genotypes. The fine root length, surface area and volume of genotype 103 increased by 69.0%, 77.0%, and 80.4%, compared with these in appropriate K treatment, and were 1.9, 2.3, and 2.6 times higher than these of genotype 122, respectively.