Abstract:

Compared with fossil energy, biomass, as the most common renewable energy source, not only has less pollution, but also helps to mitigate global warming. Therefore, the rational and effective utilization of biomass is of great significance to the sustainable development of the ecological environment. This study used soybean (Glycine max (L.) Merr.) as the carbon source of biomass, and synthesized soybean biomass carbon dots (Soy-CDs) by hydrothermal method. The prepared Soy-CDs were spherical, with an average particle size of 2.9 nm, the optimal excitation wavelength of 340 nm, the optimal emission wavelength of 440 nm, and surface rich in oxygen-containing functional groups, indicating that Soy-CDs have good fluorescent properties and biocompatibility, and the maximum yield can reach 50%. Additionally, the study further explored the effects of foliar application of different concentrations of Soy-CDs (0, 5, 10, 25 mg∙L⁻¹) on the photosynthesis, growth, and yield of corn (Zea mays L.). The results showed that 10 mg∙L⁻¹ Soy-CDs could significantly increase the net photosynthetic rate of corn leaves (208.0%), which may be due to the light conversion function of Soy-CDs increasing the absorption and utilization efficiency of light energy by corn leaves, thereby improving chlorophyll fluorescence parameters and electron transfer processes in corn leaves. At the same time, the fresh and dry masses of the aboveground part of corn increased by 53.9% and 42.1%, respectively, and the fresh and dry masses of the underground part of corn increased by 84.9% and 58.6%, respectively. The root length, root surface area, and root tips of corn increased by 83.0%, 94.7%, and 112.7%, respectively. The improvement in corn root growth will be beneficial for the absorption and utilization of soil nutrients and water by corn plants. Finally, the yield per plant of corn increased by 11.6%, the weight per 100 grains of corn seed increased by 6.5%, the length of corn ears increased by 16.2%, and the diameter of corn ears increased by 36.7%. Therefore, using biomass-synthesized biomass carbon dots (B-CDs) not only has the superior properties of CDs themselves, but also reduces the synthesis cost of CDs, improves the yield rate, achieves resource utilization of biomass, and is conducive to sustainable environmental development. At the same time, under appropriate concentrations, B-CDs can effectively promote crop growth and yield, providing data support for the application of carbon nanomaterials in agriculture.

Key words: biomass carbon dots, soybean, maize, photosynthesis, yield traits

摘要：

与化石能源相比，生物质作为最常见的可再生能源，不仅污染小，还有助于缓解全球变暖。因此，合理有效的利用生物质对生态环境的可持续发展具有重要意义。以大豆（Glycine max）为生物质碳源，通过水热法合成了大豆生物质碳点（Soy-CDs）。制备的Soy-CDs呈球形，平均粒径为2.9 nm，最佳激发波长为340 nm，最佳发射波长为440 nm，表面富含含氧官能团，表明Soy-CDs具有良好荧光特性及生物相容性，且最大产率可达50%。此外，进一步探究了叶施不同质量浓度的Soy-CDs（0、5、10、25 mg∙L⁻¹）对玉米（Zea mays）光合、生长及产量的影响。结果表明，10 mg∙L⁻¹的Soy-CDs可显著提高玉米叶片的净光合速率（208.0%），其可能原因是Soy-CDs的光转换功能增加了玉米叶片对光能的吸收和利用效率，进而改善了玉米叶片的叶绿素荧光参数及电子传递过程。同时，玉米地上部的鲜质量和干质量分别增加53.9%和42.1%，玉米地下部的鲜质量和干质量分别增加84.9%和58.6%。玉米根长、根表面积及根尖数分别增加了83.0%、94.7%和112.7%。玉米根部生长的改善将有利于玉米植株对土壤养分和水分的吸收利用。玉米单株产量增加了11.6%，玉米籽粒的百粒质量提升了6.5%，玉米棒长增加16.2%以及棒直径增加36.7%。综上，利用生物质合成的生物质碳点（B-CDs），不仅具有CDs本身的优越性质，还能降低CDs的合成成本，提高产率，实现了生物质的资源化，有利于环境的可持续发展。同时，在适当浓度下B-CDs还能有效促进作物生长和产量，为碳纳米肥料在农业中的应用提供了数据支撑。

关键词: 生物质碳点, 大豆, 玉米, 光合作用, 产量性状