热带亚热带植物学报2026，Vol.34Issue(3)：309-316,8.DOI:10.11926/jtsb.5026
轻木幼苗光合特性和生长对干旱胁迫的响应
Responses of Photosynthetic Traits and Growth of Ochroma lagopus Seedlings to Drought Stress
摘要
Abstract
Ochroma lagopus,an important fast-growing tropical timber tree species,has been successfully introduced and cultivated in the tropical regions of southwest China.However,the region's distinct tropical monsoon climate,characterized by a pronounced seasonal drought lasting half a year,poses significant challenges to growth and large-scale industrial production of O.lagopus.To reveal the response mechanism of O.lagopus seedlings to drought,gradient water stress treatments were set up.The key photosynthetic parameters,such as net photosynthetic rate(Pn),stomatal conductance(gs),intercellular CO₂ concentration(Ci),transpiration rate(Tr),and water use efficiency(WUE)were measured.Growth indicators,such as plant height and basal diameter,as well as biomass allocation characteristics,such as dry weight and proportion of roots,stems,and leaves were monitored.The effects of drought stress on the photosynthetic physiology and growth characteristics of O.lagopus seedlings were systematically studied.The results showed that drought stress significantly inhibited the plant height,ground diameter and biomass accumulation of O.lagopus seedlings.Under mild drought stress,Pn,gs and Ci decreased simultaneously,indicating that stomatal limitation was the main cause of photosynthetic inhibition.The significant reduction in biomass under mild to moderate drought was mainly due to the insufficient supply of carbon assimilates caused by restricted photosynthesis.At the same time,the increase in WUE helped maintain the balance between water conservation and carbon assimilation under drought conditions.Therefore,in the field cultivation of O.lagopus,providing appropriate water supply through water-saving irrigation techniques such as drip irrigation during the dry season to maintain soil moisture at 80%to 85%of field capacity can significantly improve the photosynthetic efficiency and biomass accumulation capacity of O.lagopus,thereby achieving the purpose of optimizing the cultivation management of O.lagopus and increasing wood volume.关键词
轻木/净光合速率/生长/生物量/水分胁迫Key words
Ochroma lagopus/Net photosynthesis rate/Growth/Biomass/Water stress引用本文复制引用
冯铭,岩应叫,栗忠飞,张树斌..轻木幼苗光合特性和生长对干旱胁迫的响应[J].热带亚热带植物学报,2026,34(3):309-316,8.基金项目
中国科学院企业合作项目(E4HX061B01) （E4HX061B01）
云南省中青年学术和技术带头人后备人才项目(202405AC350012)资助 This study was supported by the Project of Chinese Academy of Sciences and Enterprise Cooperation(Grant No.E4HX061B01),and the Program for Youth Academic and Technical Leading Talent Reserve in Yunnan(Grant No.202405AC350012). （202405AC350012）
