3种唇形科野生花卉在遮光下的光合特性变化及耐阴性评价

Photosynthetic characteristics changes and evaluation on shade tolerance of three kinds of Lamiaceae wild flowers under shading

  • 摘要: 【目的】探究遮光对唇形科花卉形态、光合作用及叶绿素荧光参数的影响,为唇形科野生花卉开发利用提供理论依据。【方法】以益母草(Leonurus japonicus)、活血丹(Glechoma longituba)和紫背金盘(Ajuga nipponensis)盆栽为试验材料,分别进行30%、50%、70%和90%的遮光处理,以不遮光为对照(CK),测定3种唇形科花卉的光合指标及叶绿素荧光指标,并运用主成分分析和隶属函数法对其进行耐阴性评价。【结果】经遮光处理的3种唇形科花卉,其叶长、叶宽和株高均高于CK,叶片含水量与遮光度呈正相关,比叶重与遮光度呈负相关。遮光处理的益母草和活血丹的各光合色素含量随着遮光度的增加持续上升,紫背金盘则表现为先升后降的变化趋势;活血丹和紫背金盘的叶绿素a/b (Chla/b)均显著低于CK (P<0.05)。随遮阴度的增加,3种唇形科花卉的表观量子效率(AQY)呈先升后降的变化趋势,光饱和点(LSP)、光补偿点(LCP)和暗呼吸速率(Rd)呈下降趋势,益母草的最大净光合速率(Pnmax)呈先升后降的变化趋势,活血丹和紫背金盘的Pnmax则一直下降;除初始荧光(Fo)、单位反应中心吸收的光能(ABS/RC)和热耗散的能量(DIo/RC) 3个叶绿素荧光参数,3种唇形科花卉在遮光下的叶绿素荧光参数值均较CK有不同程度的上升。运用主成分分析和隶属函数对上述指标进行综合评价,活血丹和紫背金盘的耐阴性较益母草好。【结论】光照强度的减小导致益母草、活血丹和紫背金盘的形态、光合特性及叶绿素荧光参数受影响程度不同,表现出不同的耐阴性,益母草较适宜生长的遮光环境为30%遮光度,活血丹和紫背金盘则在50%遮光度下生长效果更好。

     

    Abstract: 【Objective】 This study explored the effects of shading on morphology, photosynthetic indexes and chlorophyll fluorescence parameters of Lamiaceae flowers, in order to provide theoretical basis for Lamiaceae flowers' development and utilization.【Method】 Leonurus japonicus, Glechoma longituba, Ajuga nipponensis of potted flowers as tested materials were subjected to 30%, 50%, 70% and 90% shading treatment, with unshading ones as control(CK). Their photosynthetic indexes and chlorophyll fluorescence parameters were studied, and the shade tolerance was evaluated by principal component analysis and membership function.【Result】 The leaf length, leaf width and plant height of the three kinds of Lamiaceae flowers treated with shading were higher than those of CK. Leaf water content was positively correlated with shading intensity, while leaf weight was negatively correlated with shading intensity. The photosynthetic pigment contents of L. japonicus and G. longituba under shading treatment continued to increase with the increase of shading intensity. A. nipponensis showed a change trend of rising first and then falling. The chlorophyll a/b(Chla/b) of G. longituba and A. nipponensis were both significantly lower than those of CK(P<0.05). With the increase of shading intensity, the apparent quantum yield(AQY) of the three kinds of Lamiaceae flowers increased first and then decreased. and the light saturation point(LSP), light compensation point(LCP) and dark respiration rate(Rd) decreased. The maximum net photosynthetic rate(Pnmax) of L. japonicus increased first and then decreased, while the Pnmax of G. longituba and A. nipponensis decreased all the time. Except for chlorophyll fluorescence parameters of initial fluorescence(Fo), absorbed light energy per unit area(ABS/RC) and dissipated energy(DIo/RC), the values of the remaining parameters of the three kinds of Lamiaceae flowers increased to different degrees under shading compared with CK. Using principal component analysis and membership function to comprehensively evaluate above indexes, the results showed that the shade tolerance of G. longituba and A. nipponensis was better than that of L. japonicus.【Conclusion】 With the decrease of light intensity, the morphology, photosynthetic characteristics and chlorophyll fluorescence parameters of L. japonicus, G. longituba and A. nipponensis are affected differently, and show different shade tolerance. The suitable shading environment for L. japonicus is 30% shading, while the growth of G. longituba and A. nipponensis is better under 50% shading.

     

/

返回文章
返回