Effect of Different Cultivation Medium on Photosynthetic Properties of Hedera nepalensis var. sinensis under Drought Stress

Experiments were conducted on comparisons on relative water content of common cultivation medium（pine bark: peat: pearlite: river sand=5:4:0.6:0.4）, ‘Pafcal’ and ‘Tan Mian’ for 30 days, and on drought stress to 1-year Hedera nepalensis var. sinensis seedlings planted in above-mentioned three medium during July the 1st to 30th 2015. Determinations were implemented on the photosynthetic properties and chlorophyll content in the 0 day（CK）, 10th day, 20th day under drought stress and 10th day after rehydration by air seasoning method. The result showed that relative water content was the highest in common medium, followed by ‘Tan Mian’ and ‘Pafcal’. Photosynthetic parameters of seedling in the tested medium under drought stress had similar variation, however that in ‘Pafcal’ was significantly larger. H. nepalensis var. sinensis had the strongest drought adaptability in the common medium, followed by ‘Tan Mian’ and ‘Pafcal’, the same order of relative water content. Photosynthetic parameters of seedlings in ‘Pafcal’ under severe drought stress had larger change, indicating that seedlings could not tolerate long-term drought stress in the medium. After rehydration, seedlings in the common medium and ‘Tan Mian’ had better recovered than that in ‘Pafcal’.