不同基因型烤烟根系生长和生理指标对低钾胁迫的响应

Responses of Roots Growth and Physiological Indexes of Different Flue-cured Tobacco Genotypes to Low Potassium Stress

为揭示不同基因型烤烟对低钾胁迫的响应,以低钾基因型烤烟品种K326和高钾基因型烤烟品系GK8(课题组选育)为材料,通过水培试验分析了低钾胁迫对不同烤烟品种(系)根系生长和生理特性的影响。结果表明:在低钾胁迫下,两个基因型烤烟的株高、根干质量和地上部干质量均受到抑制,但K326在正常钾和低钾处理间的差异较大而GK8的差异较小,说明对低钾基因型K326的抑制程度明显高于高钾基因型GK8。在低钾胁迫下,烤烟根系体积和根系活力均有所降低,但GK8根系体积和活力均显著高于K326。低钾胁迫使烤烟烟叶绿素含量、阳离子交换量(CEC)、可溶性蛋白含量、硝酸还原酶(NR)和ATP酶活性降低,且K326下降幅度显著高于GK8。

To reveal the responses of different tobacco genotypes to low potassium stress, flue-cured tobacco cv. K326 （low potassium content genotype） and GK8 line （high potassium content genotypes, bred by the research group of this study） were used as experimental materials, the effects of low potassium stress were investigated with water culture experiments. The results showed that under low potassium stress, the plant height, dry weight of roots and aerial part of the two genotypes were inhibited, and the difference of K326 between normal potassium and low potassium treatments was more obvious than that of GK8, which indicated that K326 was more sensitive. Under low potassium stress, the volume and vigor of roots of the two genotypes were decreased, however those of GK8 were significantly higher; chlorophyll content, cation exchange capacity, soluble protein content, nitrate reductase activity, ATPase activity decreased more significantly in K326.