抗旱节水化控制剂对珙桐幼苗抗旱性的影响：模型构建、主效应与交互效应分析及最优选择

Effects of water-saving agents on drought resistance of Davidia involucrate seedlings:Model construction,principal and mutual effect analysis,and optimization choice

采用二次回归通用旋转组合设计,对国家一级保护珍惜植物珙桐(Davidia involucrate)幼苗进行盆栽控水试验,研究了水分胁迫下氯化钙(CaCl2)、水杨酸(SA)和保水剂对珙桐幼苗抗旱性的影响。结果表明:CaCl2、SA和保水剂对珙桐幼苗抗旱性的影响均呈正向作用,且它们之间具有协同效应;CaCl2和SA提高了珙桐幼苗在水分胁迫前期对土壤水分的利用,使幼苗维持了较高的抗旱性;随着土壤干旱的持续,保水剂对水分胁迫有缓效作用,使土壤维持了较高的水分含量,有利于保持幼苗的抗旱性,减小水分胁迫的危害。综合各抗旱生理特性指标得出最佳的农艺措施为:CaCl2839.400～1256.520mg·L-1、SA44.015～69.306mg·L-1、保水剂618～700ml·pot-1。

Davidia involucrate, a relic species of paleotropical kingdom in Tertiary period and belonging to Davidiaceae with a single genus, is one of the first-class protective plants in China. In this paper, a pot culture experiment with quadratic general rotation design was conducted to study the effects of CaCl2, salicylic acid （ SA）, and a water-retention agent on the drought resistance of D. involucrate seedlings. The results showed that all test reagents had positive effects, and synergistic effect existed among them. CaCl2 and SA improved the water utilization efficiency Of D. involucrate at the initial stage of water stress, while water-retention agent maintained higher soil moisture content when the drought stress developed so as to improve the drought resistance of D. involucrate and alleviate the effects of water stress. The optimum combination of management practice in improving drought resistance of D. involucrate seedlings was 839. 400-1256. 520 mg ·L^-1 CaCl2, 44. 015-69. 306 mg · L^-1 SA, and 618-700 ml ·pot^-1 water-retention agent.