氧化石墨烯与盐度对白骨壤幼苗早期生长的影响

Effects of Graphene Oxide and Salinity on the Early Growth of Avicennia marina Seedlings

摘要: 为探究氧化石墨烯(Graphene Oxide, GO)与盐度复合胁迫对红树植物白骨壤(Avicennia marina)幼苗早期生长的影响，明确其交互作用机制与耐受阈值，文章以白骨壤种子为研究对象，采用Box-Behnken响应面法设计双因素三水平试验，设置GO浓度(0、100、200 mg/L)和盐度(0、10‰、20‰)共13组处理，以河沙为生长基质进行盆栽试验。测定根系形态指标(根系长度、根尖数、根系投影面积)及生物量，通过Design-Expert13进行回归建模与多目标优化。结果表明：1) GO浓度与盐度对白骨壤幼苗生长具有显著交互效应(P < 0.05)，其中GO浓度为主导因子(在对生物量、根系长度、投影面积、根尖数的方差分析中，GO浓度的F值分别为146.37、84.59、66.12、81.53，而盐度的F值分别为34.58、19.46、13.18、24.08，GO在各形态指标的F值均大于盐度)。2) 以根系生物量、根系长度、根尖个数、投影面积为响应值进行多目标优化，获得最佳复合条件：GO浓度为0.171 mg/L，盐度为0.74‰。此时理论生物量为0.151 g、根系长度为200.148 mm、根尖个数为33个、投影面积为157.638 mm²。最优GO浓度(0.171 mg/L)低于试验最低浓度(100 mg/L)，优化结果为模型外推预测，需通过设置更低浓度梯度的试验进一步验证。研究为滨海湿地植物在纳米材料复合污染生态风险评估及红树林生态修复提供了理论依据。

Abstract: To investigate the effects of the combined stress of graphene oxide (GO) and salinity on the early growth of Avicennia marina seedlings, and to elucidate their interaction mechanisms and tolerance thresholds, Avicennia marina seeds were used as research material. A two-factor, three-level experiment was designed using the Box-Behnken response surface methodology, comprising 13 treatment combinations with GO concentrations (0, 100, 200 mg/L) and salinity levels (0, 10‰, 20‰). A pot experiment was conducted using river sand as the growth substrate. Root morphological parameters (root length, number of root tips, root projection area) and biomass were measured. Regression modeling and multi-objective optimization were performed using Design-Expert 13. The results showed that: 1) GO concentration and salinity exhibited a significant interactive effect on seedling growth (P < 0.05), with GO concentration being the dominant factor (in the ANOVA for biomass, root length, projection area, and number of root tips, the F-values for GO concentration were 146.37, 84.59, 66.12, and 81.53, respectively, while those for salinity were 34.58, 19.46, 13.18, and 24.08; the F-values for GO were higher than those for salinity across all morphological indices). 2) Using root biomass, root length, number of root tips, and projection area as response values, multi-objective optimization yielded the optimal combined conditions: GO concentration of 0.171 mg/L and salinity of 0.74‰. Under these conditions, the theoretical values were: biomass of 0.151 g, root length of 200.148 mm, number of root tips of 33, and projection area of 157.638 mm². The optimal GO concentration (0.171 mg/L) was lower than the lowest experimental concentration (100 mg/L), indicating that the optimization result was derived from model extrapolation, which requires further validation through experiments with lower concentration gradients. This study provides a theoretical basis for ecological risk assessment of nanomaterial combined pollution in coastal wetland plants and for mangrove ecological restoration.