摘要
为探明短命植物的光合适应性,本研究以卷果涩芥(Malcolmia scorpioides)和硬萼软紫草(Arnebia decumbens)为试验对象,研究了遮阴率为75%的4个时间梯度(0、1、7、14 d)下两种短命植物叶绿素荧光日变化及遮阴14 d后叶绿素含量和生物量的变化。结果表明:1) 0 d时,两种短命植物最大光化学效率(Fv/Fm),实际光合效率Y (Ⅰ)和Y (Ⅱ)在午间(14:00)明显降低(P <0.05),存在午间光抑。2)遮阴1和7 d,两种短命植物光合效率日变化呈“单峰”型曲线,14:00时上升至峰值,并伴随环式电子传递流量子产量[Y (CEF)]上升,光抑制被改善;14 d时,卷果涩芥PSⅠ受体端限制引起的量子产量[Y (NA)]和PSⅡ非调节性能量耗散的量子产量[Y (NO)]升高,光系统受损,光合活性下降。3)与未遮阴环境相比,遮阴环境的午间14:00卷果涩芥光合活性下降95.3%,光损伤程度增加95.0%,硬萼软紫草光合活性上升4.0%,热耗散效率下降18.6%。4)遮阴14 d后,两种短命植物的叶绿素含量和生物量均下降,且卷果涩芥的下降率高于硬萼软紫草。综上,硬萼软紫草较卷果涩芥耐阴,14 d内的遮阴均可提高硬萼软紫草的光保护能力,改善光抑制,而卷果涩芥的改善效果仅限7 d内,超过7 d时光合利用率降低。
In order to explore the photosynthetic adaptability of ephemeral plants,this paper took Malcolmia scorpioides and Arnebia decumbens as the experimental objects.The daily changes in chlorophyll fluorescence and the changes in chlorophyll content and biomass of two ephemeral plants were studied under four time gradients(0,1,7,14 d)with a shading rate of 75%.The results showed that:1)At 0 d,the maximum photochemical efficiency(Fv/Fm)and the actual photosynthetic efficiency Y(Ⅰ)and Y(Ⅱ)of the two ephemeral plants decreased significantly at mid-afternoon(14:00),showing a phenomenon of“midday photoinhibition”.2)After being shaded for 1 and 7 d,the diurnal variation of photosynthetic efficiency of the two ephemeral plants showed a“single peak”curve.This increased to the peak value at 14:00,and the quantum yield of cyclic electron flow Y(CEF)increased,and the midday photoinhibition was improved.At 14 d,the quantum yield caused by PSⅠacceptor-side limitation Y(NA)and the quantum yield of non-regulated energy dissipation in PSⅡY(NO)increased,the photosynthetic system was damaged,and the photosynthetic activity decreased.3)Compared with the unshaded environment,at 14:00,the photosynthetic activity of M.scorpioides decreased by 95.3%and the degree of light damage increased by 95%under shade.However,the photosynthetic activity of A.decumbens increased by 4%and heat dissipation efficiency decreased by 18.6%.4)After 14 d of shading,the chlorophyll content and biomass of the two ephemeral plants decreased,and the decline rate of M.scorpioides was higher than that of A.decumbens.In conclusion,the shade tolerance of A.decumbens is higher than that of M.scorpioides.Shading within 14 d can improve the light protection ability of A.decumbens and improve the light inhibition.Meanwhile,the improvement effect of M.scorpioides was only within 7 d,and the photosynthetic utilization rate decreased after 7 d.
作者
付慧蓉
李嫚
景玉婷
赵恒明
伍勇
张城铭
刘红玲
庄丽
FU Huirong;LI Man;JING Yuting;ZHAO Hengming;WU Yong;ZHANG Chengming;LIU Hongling;ZHUANG Li(College of Life Sciences,Shihezi University,Shihezi 832003,Xinjiang,China;College of Chemistry and Life Sciences Sichuan Provincial Key Laboratory for Development and Utilization of Characteristic Horticultural Biological Resources,Chengdu Normal University,Chengdu 611130,Sichuan,China)
出处
《草业科学》
CAS
CSCD
北大核心
2024年第2期241-251,共11页
Pratacultural Science
基金
国家自然科学基金项目(31871568、31560656)
成都师范学院创新研究团队项目(CSCXTD2020A04)。
关键词
光抑制
光损伤
光保护
光合效率
日变化
卷果涩芥
硬萼软紫草
photoinhibition
photodamage
photoprotection
photosynthetic efficiency
diurnal variation
Malcolmia scorpioides
Arnebia decumbens
