团花幼苗对土壤干旱胁迫的生长和生理生化响应

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Growth and physiological-biochemical responses of Neolamarckia cadamba seedlings to soil drought stress

GAN Ziye， SHAO Guodong， SULicheng， ZHU Jieyi， ZENG Shucai （College ofForestryand Landscape Architecture， South China Agricultural University， Guangzhou 50642， China）

Abstract： 【Objective】 To investigate the growth and physiological-biochemical responses of Neolamarckia cadamba seedlings under varying soil drought stress gradients，and provide a scientific basis for water management in cultivation of N. cadamba seedlings. 【Method】 A controlled pot experiment was conducted with four drought treatments： control [CK， 80%-85% field capacity （FC）]， light drought （LD， 65%-70% FC）， moderate drought （MD， 50%-55% FC）， and severe drought （SD， 35%-40% FC）. Seedling height， ground diameter， root morphology， leaf morphological traits， osmoregulatory substances contents and antioxidant enzyme activities were measured. Fuzzy membership function analysis was used to comprehensively evaluate the adaptability of N. cadamba under different treatments. 【Result】 Drought stress significantly reduced leaf length， leaf width and leaf area （P<0.05） ） but did not affect the leaf length-to-width ratio. MD and SD significantly decreased seedling height， ground diameter，and superoxide dismutase activity， while significantly increased soluble protein and malondialdehyde contents （P<0.05） . LD had no significant impact. SD significantly reduced seedling biomass， root length， root surface area， and root volume （ （P<0.05） .Averageroot diameter， soluble sugar content， proline content， and peroxidase activity showed no significant difference among treatments. Comprehensive evaluation by fuzzy membership function analysis ranked the growth and physiological-biochemical performance ofN. cadamba seedlings under different treatments as CK>LD>MD> SD.【Conclusion】 N. cadamba seedlings grow optimally under well-watered conditions， tolerate light drought with limited impact， but sufer significant growth inhibition and oxidative damage under moderate and severe drought.N.cadamba exhibits weak drought tolerance，and therefore prolonged moderate or severe soil drought should be avoided in cultivation.

Keywords： Neolamarckia cadamba; Drought stress; Water physiology; Membership function analysis

我国华南地区属于典型的亚热带季风气候，雨热同期、水资源丰富，但受降水季节分布不均的影响，区域性干旱现象频发[]。（剩余11227字）