氮磷对马蹄金抗旱性的影响

Nitrogen and Phosphorus Effect on Drought-Resistance of Dichondra Repens in Different Growing Stages

研究氮磷对马蹄金(D ichond ra rep ens)出苗期、成坪期、旺盛期和衰退期抗旱生理指标的影响。结果表明:施磷后马蹄金根系活力上升,超氧化物歧化酶活性提高,增强了避旱能力,其中高磷(1.50 kg P2O5/100 m2)的效果最好;低氮(0.24 kg N/100 m2、0.57 kg N/100 m2)使叶片脯氨酸、可溶性糖和叶绿素含量增加,通过渗透调节提高其耐旱性,但高氮则使叶片超氧化物歧化酶活性降低,丙二醛大量累积,加重了水分胁迫程度;马蹄金受水肥影响最主要的抗旱生理指标为:叶片脯氨酸含量、根系活力和叶绿素含量。

Dichondra repens had been chosen as the material for studying nitrogen and phosphorus effect on the plant＇s drought-resistance indexes in water stress during the emerging, turf forming, vigorously growing, and declining stages. The results of the experiment are as follows： Applying the fertilizer P raised D. repens＇ root vitality and superoxide dismutase activity, consequently, strengthened its drought-avoidance. Plentiful P （1.50 kg P2O5/100m^2） was optimum. Low and medium amount of N （ 0. 24 kg N/100 m^2. 0. 57 kg N/100 m^2） increased the contents of proline, soluble sugar, and chlorophyll, which strengthened D. repens＇ droughttolerance through osmotic adjustment. Excessive amount of N led to the decline of superoxide dismutase activity and the accumulation of malondialdehyde, which aggravated water stress. D. repens＇ proline content, root vitality, and chlorophyll content gave the most sensitive indexes to the influence of water and fertilizers that resist drought.