纳米氧化硅对髯毛箬竹光合荧光特性的影响

以髯毛箬竹为试验对象,采用叶面喷施的处理方法,研究不同质量浓度的纳米SiO2(150、300、450 mg/L)对髯毛箬竹光合荧光特性的影响。结果显示:在整个试验期间,与对照相比,各浓度的纳米SiO2处理均能不同程度地促进髯毛箬竹净光合速率、气孔导度、蒸腾速率等气体交换参数和PSⅡ潜在活性、有效光化学量子产量、实际光化学量子产量、电子传递速率和光化学猝灭系数等叶绿素荧光参数的升高,其中以300 mg/L纳米SiO2处理效果最佳。该浓度纳米SiO2处理21 d时以上各参数分别比对照增加23.6%、34.9%、20.4%、8.8%、7.9%、26.6%、34.1%和19.3%,均与对照差异显著(p<0.05)。但对胞间CO2浓度和PSⅡ最大光化学效率的影响作用不明显(p>0.05),处理后期对非光化学猝灭系数有明显抑制作用。实验结果说明适当浓度的纳米SiO2能有效改善髯毛箬竹叶片气孔导度,促进叶片对光能的吸收、传递和转化,增大光系统Ⅱ反应中心的开放程度,降低光能热耗散,提高光系统Ⅱ的实际光化学效率和电子传递速率,进而提高髯毛箬竹的净光合能力。叶肉细胞光化学活性的提高是纳米SiO2促进髯毛箬竹光合能力提高的主要因素。

Effects of nano-silicon dioxide on photosynthetic fluorescence characteristics of Indocalamus barbatus McClure

In order to explore the regulating effects of nano materils on the the growth and development of bamboos,we measured the effects of different concentrations of nano SiO2(150,300,450 mg/L) on Indocalamus barbatus McClure by foliar spraying.The results showed that compared to control,all treatments of different concentrations of nano SiO2 could increase the gas exchange parameters and chlorophyll fluorescence parameters to some extent during the experiment,such as net photosynthetic rate,transpiration rate,stomatal conductance,PSⅡ potential activity,effective photochemical efficiency,actual photochemical efficiency,electron transport rate and photochemical quench,the optimal concentration of nano-SiO2 was 300 mg/L.Compared to control,the above parameters significantly(p<0.05) increased 23.6 %,34.9 %,20.4 %,8.8 %,7.9 %,26.6 %,34.1 % and 19.3 % respectively after 21 days,but the intercellular CO2 concentrations and PSⅡ maximal photochemical efficiency were not obviously(p>0.05) changed,and the non-photochemical quench was inhibited in the late experiment period.All above results indicated that exogenous nano SiO2 treatment could effectively improve the stomatal conductance of In.barbatus McClure,promote the leaves(function on the absorption,transmission and transformation of light energy,increase the opening degree of PSⅡ reaction centers,reduce the antenna dissipation,improve actual photochemical efficiency and electron transport rate of PSⅡ,and then to improve net photosynthetic capacity of In.barbatus McClure.The improvement of photosynthetic activity of mesophyll cells may be the major factor of nano SiO2 to promote the photosynthetic capacity of In.barbatus McClure.