开花麻竹叶绿素荧光参数测定

叶绿素荧光是研究光合作用的有效探针。为了探讨开花对麻竹光合作用的影响,应用PAM-100分别测定了开花与未开化麻竹的叶绿素荧光参数。结果表明,随着光强的升高0~2 000μmol/（m^2·s）],在开始阶段0~200μmol/（m^2·s）]麻竹叶片的NPQ、Y（NPQ）、Y（ND）、ETR（Ⅱ）和ETR（Ⅰ）均迅速升高,Y（Ⅱ）和Y（Ⅰ）却迅速下降,之后变化缓慢并趋于平稳,而Y（NA）和Y（NO）几乎一直维持平稳;其中未开花麻竹的NPQ、Y（Ⅰ）和ETR（Ⅰ）均高于开花麻竹,Y（Ⅱ）、Fv/Fm和ETR（Ⅱ）无明显差异。在本实验培养光照下230μmol/（m2·s）],未开花麻竹的NPQ、Y（Ⅰ）和ETR（Ⅰ）也均高于开花麻竹。由此表明,开花引起麻竹PSⅠ的Y（Ⅰ）和ETR（Ⅰ）以及PSⅡ的NPQ降低,这意味着开花麻竹的光保护能力下降,使得PSⅠ受体侧电子积累,导致光合效率下降。

Measurement of Chlorophyll Fluorescence Parameters of Flowering Dendrocalamus latiflorus

Chlorophyll fluorescence is an effective probe for photosynthesis research. Flowering and non flowering ma bamboo（Dendrocalamus latiflorus） seedlings at the age of 2 were selected as materia1 to investigate the chlorophyll fluorescence parameters of PSⅠ and PSⅡ using Dual-PAM-100, respectively. The results showed that with the increasing of light intensity 0~2 000μmol/（m^2·s）], the values of NPQ, Y（NPQ）, Y（ND）, ETR（Ⅱ） and ETR（Ⅰ） enhanced while the value of Y（Ⅰ） and Y（Ⅱ） decreased rapidly at the beginning0~200 μmol/（m^2·s）], but the following upward trend slowed down and then became stable, and however the values of Y（NA） and Y（NO） remained almost stable. There was no obvious difference between flowering and non flowering ma bamboo for the values of Y（Ⅱ）, Fv/Fm and ETR（Ⅱ）, while the values of NPQ, Y（Ⅰ）, ETR（Ⅰ） for non flowering ma bamboo were higher than those of flowering ma bamboo correspondingly. Under the normal light intensity of environment 230 μmol（m2·s）], the values of NPQ, Y（Ⅰ）, ETR（Ⅰ） for non flowering ma bamboo were also higher than those of flowering ma bamboo correspondingly. It was suggested that flowering caused the decline of Y（Ⅰ） and ETR（Ⅰ） of PSⅠ as well as NPQ of PSⅡ in ma bamboo, which indicated that the photoprotective capacity of flowering ma bamboo decreased, resulting in the decline of photosynthetic efficiency caused by the accumulation of electron at acceptor side in PSⅠ.