摘要
采用人工遮荫法研究不同程度遮荫（75％、50％和25％全光照，以全光照为对照）处理对月季的生长发育、光合特性及叶绿素荧光参数的影响。结果表明：（1）随着遮荫程度的增加，月季的叶片厚度、花径、成花率均呈降低趋势，叶绿素含量呈增加趋势；净光合速率（Pn）、蒸腾速率（rrr）、气孔导度（Gs）、胞间CO2浓度（C。）降低，气孔限制值（Ls）升高，Pn下降的主要原因可能为气孔限制。（2）月季在遮荫条件下的光饱和点和光补偿点、暗呼吸速率下降，表现出其对光照降低的生理适应机制；其光饱和点在600～1200μmol·m^-2·s^-1，光补偿点在29．89～62．95μmol·m^-2·S^-1，C02补偿点在78．16～89．41μmol·mol^-1，CO2饱和点在1100μmol·mol^-1左右，潜在光合能力13．06～25．63μmol·m^-2·s^-1，其对光的适应范围较宽，光照和CO2浓度对其光合能力的影响较大。（3）各处理条件下叶绿素荧光参数显示，月季在自然光和低光下（50％和25％全光照）叶片PSⅡ受到了明显伤害，光合作用原初反应过程受到抑制，光合电子传递受到影响。研究发现，月季虽是阳生植物，但光照生态幅较宽，轻度遮荫（75％全光照）能促进其光合作用效率，减少光抑制，植株长势好，成花率高。
The effects of different shading treatments （25%,50%,75% and 100% of full sunlight） on the growth, photosynthetic characteristics and chlorophyll fluorescence parameters of Rosa hybrida were exam- ined in order to know the growth and physiological responses of R. hybrida to light regimes. （1）It has been found that with the decreasing light intensity, the leaf thickness, and flower diameter and flower formation rate decreased,while the Chl content increased. The net photosynthetic rate （Pn）,transpiration rate （Tr）, stomatal conductance （G~） and intercellular CO2 concentration （Ci） all decreased with the decreasing of light intensity, while the stomatal limitation value （L~） increased. （2）The light compensation point （LCP） ,light saturation point （LSP） and dark respiration rate （Ra） also decreased as a mechanism of phys- iological adaptability to light decreasing. The adaptability of R. hybrida to light was wide because the LSP was 600- 200μmol . m^-2. s^- 1 and the LCP was 29.89-62.95 μmol . m^-2 . s^-1. The CO2 compensation The chlorophyll fluorescence parameters indicated that with the increasing of light stress, the reaction center of PS Ⅱ was destroyed,photosynthetic electron transform capability was weakened and photosynthesis was restrained. It is indicated that R. hybrida is a sun plant with shade tolerance. Moderate shading （75% of full sunlight） can improve its photosynthetic capacity and the flower quality,and reduce the photoinhibi- tion in R. h ybrida.
出处
《西北植物学报》
CAS
CSCD
北大核心
2014年第1期162-168,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
四川省教育厅重点项目(12ZZ011)
四川农业大学学科建设双支计划
关键词
月季
遮荫
光合特性
叶绿素荧光
Rosa hybrida
shading treatment
photosynthetic characteristics
chlorophyll fluorescence
