生态科学2018，Vol.37Issue(6)：168-174,7.DOI:10.14108/j.cnki.1008-8873.2018.06.022
延胡索光合与生长可塑性对光照的响应
Responses of photosynthesis and growth plasticity of Corydalis yanhusuo to light
摘要
Abstract
Medicinal plant-based agroforestry systems have considerable economic benefits.In the present study, the changes in the photosynthesis and growth of the early spring plant, Corydalis yanhusuo, under different light conditions were analyzed.This was done to provide a scientific basis for understory tending, canopy thinning, and development of medicinal plant-based agroforestry systems using this species.It was found that C.yanhusuo adapted to shaded and low-light environments by decreasing its light saturation point, light compensation point, and dark respiration rate, and increasing its apparent quantum yield.Differences in the performance of C.yanhusuo under full-and medium-light conditions were not significant.Particularly, the mean values for dark respiration rate and maximum net photosynthetic rate under medium-light conditions were higher than those under full-light conditions.The saturation light intensity, maximum net photosynthetic rate, and apparent quantum yield under low-light conditions were 62.67％, 43.25％, and 58.42％of the values under full-light conditions, respectively.The net photosynthetic rate, stomatal conductance, and transpiration rate under shaded conditions were generally lower than the corresponding values under full-light conditions.After shading, Chl a, Chl b, and Chl a+Chl b levels in the leaves of C.yanhusuo initially increased and subsequently decreased as photosynthetically active radiation decreased.Under medium-high-and medium-low-light conditions, the Chl a:Chl b ratio significantly decreased.This demonstrates the shade tolerance of this species, whereas the significant decrease in the Chl a:Chl b ratio under low-light conditions is attributed to the insufficient supply of photosynthates and reduced chlorophyll synthesis caused by low light.The leaf and root biomasses of C.yanhusuo under low-light conditions were only 34.78％and 22.03％of the values obtained under full-light conditions, respectively.With a decrease in photosynthetically active radiation, the specific leaf area initially increased and subsequently decreased, indicating that C.yanhusuo prioritizes the morphological construction of leaves over the expansion of leaf area to capture more photons under low-light conditions.The shade tolerance of C.yanhusuo is intermediate between that of light-demanding plants and shade plants, and the photosynthetic apparatus of C.yanhusuo may become similar to that of shade-tolerant plants under low-light conditions.Therefore, C.yanhusuo has a certain level of shade tolerance, but it is not well-suited for long-term exposure to low-light conditions.During the cultivation of C.yanhusuo in wild woodlands with very high canopy closure, measures such as appropriate thinning and pruning, or creation of forest gaps, can improve understory light environment and enhance photosynthetic capacity and sunfleck utilization of understory C.yanhusuo plants.These measures can then allow for reasonable allocation of light and temporal niches for the plants to achieve the expected economic benefits.关键词
延胡索/早春植物/弱光/林-药复合生态系统/生理生态Key words
C.yanhusuo/early-spring plant/weak light/tree-herb plantations/ecophysiology分类
生物科学引用本文复制引用
盛海燕,李伟成..延胡索光合与生长可塑性对光照的响应[J].生态科学,2018,37(6):168-174,7.基金项目
浙江省科技计划项目(2016F50008) （2016F50008）
浙江省省院合作项目(2015SY06) （2015SY06）
