香蕉幼苗对PEG模拟水分胁迫下氮钾营养的生理响应

为了探索香蕉作物抗旱生理对适宜的水、氮、钾组合互作效应的响应特征，水培试验中利用PEG模拟水分胁迫，研究香蕉幼苗在不同浓度的氮钾肥交互效应下，叶片相对含水量、根系活力、脯氨酸酶含量、过氧化物活性的变化，进行多重比较分析最佳抗旱效果的氮钾浓度组合。结果表明，水分胁迫对香蕉幼苗叶片POD酶活性和Pro含量的影响来说，均表现为PEG 30%>PEG 20%>PEG 10%>CK (0%)。对试验因子间的交互作用进行分析表明：（1）叶片含水量的大小顺序：PEG 5%与N 50 mg/L>PEG 15%与N 150 mg/L≈PEG 10%与N 100 mg/L；K 150 mg/L>K 200 mg/L>K 100 mg/L，且相互之间差异达到极显著。（2）香蕉幼苗根系活力大小顺序为：处理6(PEG 10%、N 150 mg/L、K 150 mg/L)>处理5(PEG 10%、N 100 mg/L、K 100 mg/L)>处理7(PEG 15%、N 50 mg/L、K150 mg/L)，此3个处理的根系活力显著高于其他处理的根系活力，但三者之间差异不显著；（3）香蕉幼苗脯氨酸含量表现为处理9(PEG 15%、N 150 mg/L、K 100 mg/L)比处理1（PEG 5%、N 50 mg/L、K 100 mg/L）的脯氨酸含量高出2.16倍。处理9极显著高于其他处理的脯氨酸含量；（4）香蕉幼苗过氧化物酶活性表现为：处理9(PEG 15%、N 150 mg/L、K 100 mg/L)比处理1(PEG 5%、N 50 mg/L、K 100 mg/L)的过氧化物酶活性高出1.46倍。处理9极显著高于其他处理的过氧化物酶活性。适当的氮、钾浓度可提高香蕉幼苗叶片相对含水量、根系活力、脯氨酸含量和过氧化物酶活性，从而减轻水分胁迫的不利影响。本试验中处理6(PEG 10%、N 150 mg/L、K 150 mg/L)为最佳的水、氮、钾的处理。

Physiological Response of Banana Seedlings to PEG Simulated Drought Stress Under Different Nitrogen and Potassium Nutrition

In order to explore the response characteristics of banana drought resistance to the suitable water, nitrogen, potassium interaction, the hydroponic experiment had been done. In this experiment, the leaf relative water content, root vitality, proline enzyme content, peroxidase activity changes of banana seedlings were studied and multiple comparisons analysis of the best drought effects combination of nitrogen and potassium concentration were done too, under different concentrations of nitrogen and potassium interaction by using PEG simulated drought stress. The results showed that: the impact of water stress on POD activity and Pro content of banana seedling leaves showed: PEG 30%>PEG 20%>PEG 10%>CK (0%). Analysis showed that: the interaction between the test factor: (1) water content of leaf size: PEG 5% & N 50 mg/L>PEG 15% & N 150 mg/L≈PEG 10% & N 100 mg/L; K 150 mg/L>K 200 mg/L>K 100 mg/L, and differences were significant between them. (2) Root activity of banana seedlings sequence: treatment 6 (PEG 10%, N 150 mg/L, K 100 mg/L)>treatment 5 (PEG 10%, N 100 mg/L, K 100 mg/L)>treatment 7 (PEG 15%, N 50 mg/L, K 150 mg/L). The root activities of the three treatments were significantly higher than the others, but there was no significant difference between them. (3) The proline content of treatment 9 (PEG 15%, N 150 mg/L, K 100 mg/L) was 2.16 times of treatment 1 (PEG 5%, N 50 mg/L, K 100 mg/L) of banana seedlings. Proline content of treatment 9 was significantly higher than those of other treatments. (4) The peroxidase activity performance of treatment 9 (PEG 15%, N 150 mg/L, K 100 mg/L) than treatment 1 (PEG 5%, N 50 mg/L, K 100 mg/L) was 1.46 times of treatment 1. Peroxidase activity of treatment 9 was significantly higher than that of other treatments. Appropriate concentrations of nitrogen and potassium could improve the leaf relative water content, root activity, proline content and peroxidase activity of banana seedling to reduce the adverse effect of water stress. In this experiment, treatment 6 (150 mg/L PEG 10%, nitrogen, potassium 150 mg/L) was the best appropriate treatment with water, nitrogen, potassium interaction on banana drought.