Abstract

Sodium metasilicate solution treatment contributes to improved plant tolerance to drought stress. In this study, pot experiments were conducted to compare the effect of sodium metasilicate solution on Malus halliana and Malus hupehensis seedlings under drought stress. Principal component analysis (PCA) was used to evaluate the effects of sodium metasilicate solutions on gas exchange, fluorescence, and physiological characteristics. Forty days after transplantation, the control (75% field capacity (FC)) and treatment 1 (50% FC) seedlings were sprayed with distilled water, and the other treatment (50% FC) seedlings were sprayed with a sodium metasilicate (Na₂SiO₃·9H₂O) solution at different concentrations. The results showed that the growth of M. halliana and M. hupehensis was inhibited when exposed to drought stress. This adverse effect was reversed by applying sodium metasilicate solution, and there was a significant concentration effect. Compared to the control, sodium metasilicate solution increased the proline (Pro) content. At the same time, the decrease in the SPAD values, net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r), initial fluorescence (F₀), maximum fluorescence (F_m), photochemical efficiency (F_v/F_m), electron transfer rate (ETR), and superoxide dismutase (SOD) activity were effectively controlled. The increase in intercellular CO₂ concentration (C_i) and malondialdehyde (MDA) content was also restricted. Additionally, the PCA showed that the first principal component of M. halliana accounted for 80.42% variance, contributed by P_n, T_r, G_s, Pro, SOD, F_v/F_m, and ETR. The first principal component of M. hupehensis accounted for 69.72% and mainly contained P_n, SPAD, and F_v/F_m index information. The PCA evaluation showed that the effect of sodium metasilicate solution on M. halliana and M. hupehensis seedlings under drought stress was most significant (p < 0.05) at concentrations of 2.5 and 3.75 mM·L⁻¹, respectively.

摘要

偏硅酸钠溶液处理有助于提高植物对干旱胁迫的耐受性。本研究通过盆栽试验比较了偏硅酸钠溶液对干旱胁迫下海棠和湖北海棠幼苗的影响。主成分分析 (PCA) 用于评估偏硅酸钠溶液对气体交换、荧光和生理特性的影响。移植后四十天，对照（75% 田间持水量（FC））和处理 1（50% FC）幼苗喷洒蒸馏水，另一处理（50% FC）幼苗喷洒偏硅酸钠（Na ₂ SiO ₃ ·9H ₂O) 不同浓度的溶液。结果表明，在干旱胁迫下， M.halliana和M.hupehensis的生长受到抑制。通过应用偏硅酸钠溶液可以逆转这种不利影响，并且有显着的浓度效应。与对照相比，偏硅酸钠溶液增加了脯氨酸（Pro）的含量。同时，SPAD值、净光合速率（P _n）、气孔导度（G _s）、蒸腾速率（T _r）、初始荧光（F ₀）、最大荧光（F _m）、光化学效率均下降。 ( F_v / F _m )、电子转移速率(ETR)和超氧化物歧化酶(SOD)活性得到有效控制。细胞间CO ₂浓度（C _i）和丙二醛（MDA）含量的增加也受到限制。此外，PCA 表明，海棠的第一主成分占80.42% 的方差，由P _n、T _r、G _s、 Pro、 SOD、F _v / F _m和 ETR 贡献。M的第一个主成分。湖北人占69.72%，主要包含_Pn 、 SPAD、Fv _/ Fm指数_信息。PCA评价表明，偏硅酸钠溶液对干旱胁迫下的海棠和湖北海棠幼苗的影响分别 在2.5和3.75 mM·L ^{-1浓度下最为显着（} p < 0.05） 。