摘要
为探究国家Ⅱ级重点保护野生植物和极小种群野生植物紫荆木(Madhuca pasquieri)光合特性,采用LI-6400 XT便携式光合仪测定紫荆木幼苗、幼树与成年株光合参数。结果表明:①直角双曲线修正模型是紫荆木幼苗、幼树和成年株的光响应拟合的最佳模型;②紫荆木成年株叶片净光合速率(P_(n))日变化有明显“午休”现象,叶片蒸腾速率(T_(r))、气孔导度(G_(s))和空气温度的日变化曲线规律相似,均呈双峰曲线。其中P_(n)、T r的最大峰值出现在10:00-11:30,分别为9.223μmol/(m 2·s)与1.979 mmol/(m 2·s);G s的最大峰值出现在14:30-16:00[0.285 mmol/(m 2·s)];③紫荆木幼苗、幼树与成年株叶片的表观量子效率(AQE)、最大净光合速率(P_(nmax))、光饱和点(LSP)、光补偿点(LCP)和暗呼吸速率(R d)均显著(P<0.05)。在一定光强范围内,紫荆木的P_(n)、G_(s)、T_(r)随着光强增加而增加,但在强光照下又表现出光抑制现象;④紫荆木幼苗、幼树与成年株的总叶绿素均显著(P<0.05)。综上所述,紫荆木P_(nmax)和LSP较高,而LCP和AQE较低,属阳生植物。紫荆木成年树对光有较强的适应能力高于幼树和幼苗;幼树对光有较强的适应能力高于幼苗。
In order to investigate the photosynthetic characteristics of Madhuca pasquieri,which is a key wild plant under State Class II protection and a very small population wild plant,a portable photosynthesizer(Li-6400)was used to determine the photosynthetic parameters of Madhuca pasquieri seedlings,juvenile trees,and adult plants in this study.The results showed that:①The right-angle hyperbola correction model was the best model for fitting the light response of seedlings,juvenile and adult plants of Madhuca pasquieri;②the daily change of net photosynthetic rate of adult Madhuca pasquieri leaves had an obvious"lunch break"phenomenon,and the daily change curves of leaf transpiration rate,stomatal conductance and air temperature were similar to each other,and all of them showed a bimodal curve.The maximum peaks of net photosynthetic rate and transpiration rate appeared at 10:00-11:30,with 9.223μmol/(m 2·s)and 1.979 mmol/(m 2·s),respectively;the maximum peak of stomatal conductance appeared at 14:30-16:000.285 mmol/(m 2·s);③the apparent quantum efficiency(AQE),maximum net photosynthetic rate(P nmax),light saturation point(LCP)and light compensation point(LSP)of leaves of seedlings,juvenile,adult plants were significant and rate of dark respiration(Rd)(P<0.05).The net photosynthetic rate,stomatal conductance,and transpiration rate of Madhuca pasquieri increased with increasing light intensity within a certain range of light intensity,but then showed photoinhibition under strong light;④total chlorophyll was significant(P<0.05)in Madhuca pasquieri seedlings,juvenile and adult plants.In conclusion,Madhuca pasquieri has higher P nmax and LSP,while LCP and AQE are lower,and it is heliophyte.Adult plants of Madhuca pasquieri had higher adaptability to light than juvenile plants and seedlings;juvenile plants had higher adaptability to light than seedlings.
作者
钟文彤
杨一山
蒋运生
邹蓉
韦霄
Zhong Wentong;Yang Yishan;Jiang Yunsheng;Zou Rong;Wei Xiao(Guangxi Normal UniversityYanshan District,Guilin 541000,Guangxi,China;Guangxi Institute of Botany,Chinese Academy of SciencesYanshan District,Guilin 541000,Guangxi,China)
出处
《绿色科技》
2024年第20期18-26,共9页
Journal of Green Science and Technology
基金
广西植物功能性植物化学物质研究与可持续利用重点实验室自主项目(编号:ZRJJ2022-2)
国家重点研发计划(编号:2022YFF1300703)
“桂科学者”创新团队启动项目(编号:CQZ-C-1902)。
关键词
紫荆木
日变化
光照强度
光合色素
光响应曲线
光响应模型
Madhuca pasquieri
daily variation
light intensity
photosynthetic pigment
light response curve
light response modeling
