Comparative Evaluation of Physiological Response and Drought Tolerance between Cunninghamia unica and C. lanceolata Seedlings under Drought Stress

Cunninghamia plays an important role in China’s southern forest industry the face of increasingly arid climate; thus it is urgent to identify and screen drought-tolerant varieties. In this study, 2-year-old seedlings C. unica lanceolata from four provenances were subjected water-break tests, their physiological responses different drought conditions observed. The results showed that with aggravation stress, had more stable changes relative water content (RWC), potential (Ψw) intercellular CO2 concentration (Ci) cumulative amounts proline (PRO) than lanceolata, its H2O2 maintained at a lower level, along antioxidant enzyme activities decreasing later as compared lanceolata. Moreover, comprehensive evaluation higher tolerance whole, which could have been shaped by maintaining Ψw opening stomata conditions. This work provides theoretical basis for understanding lanceolate individuals, so accelerate selective breeding Chinese fir.