Effects of different nitrogen and phosphorus application ratios on leaf growth and physiological characteristics of Passiflora edulis Sims

the changes of leaf growth and physiological characteristics of Passiflora edulis Sims under different nitrogen and phosphorus application ratios was studied and it can provide a theoretical basis for scientific fertilization during the vegetative growth period of Passiflora edulis Sims. The test under the pot culture condition, six treatments were set including no fertilization control（T1）, nitrogen and phosphorus ratio of 1∶1（T2）, 1.5∶1（T3）, 2∶1（T4）, 1∶1.5（T5）, 1∶2（T6）respectively, and the changes of leaf fresh weight and physiological indexes of Passiflora edulis Sims were studied. The results show that: T4 was significantly increased the fresh weight of leaves at 100 days after fertilization treatment compared with T1, T2, T3 and T5, the superoxide anion content in T4 was significantly lower than that in T1, T3 and T5 on the 25th, 75th and 100th day; T4 APX activity was significantly higher than the other five treatments; the MDA content of T4 was significantly lower than that of T1 and T2, and the soluble sugar content was significantly higher than that of the control and other nitrogen and phosphorus fertilization treatments; the proline content of T4 was significantly higher than T1, T2, T5 and T6 from the 75th day to the 100th day after fertilization. Comprehensive analysis showed that the 2∶1 ratio of nitrogen and phosphorus application in the vegetative growth period of Passiflora edulis Sims was the appropriate fertilization ratio to promote the growth of Passiflora edulis Sims leaves and improve physiological characteristics.