蜀葵-胶质芽孢杆菌联合修复土壤镉污染

为探究胶质芽孢杆菌对蜀葵修复土壤Cd污染能力的影响,采用盆栽试验,以蜀葵为供试植物,研究了25 mg·kg^-1Cd胁迫下施用3、6、9 g·kg^-1的胶质芽孢杆菌对蜀葵生物量、Cd积累量、根际土壤有效态Cd含量和根际土壤酶活性的影响。结果表明:25mg·kg^-1Cd胁迫下,施用6 g·kg^-1胶质芽孢杆菌可显著提高蜀葵根、茎生物量(P<0.05),总生物量相比单一Cd处理提高了33.6%~73.2%;施用3、6、9 g·kg^-1的胶质芽孢杆菌,蜀葵整株Cd积累量是单一Cd处理的1.64、2.89、1.69倍,蜀葵根际土壤有效态Cd含量分别上升4.8%、13.1%和8.5%。25 mg·kg^-1Cd胁迫下施用胶质芽孢杆菌后,蜀葵根际土壤脲酶、蔗糖酶活性随施用浓度增加而升高,且处理间差异显著(P<0.05);脱氢酶活性在施用3 g·kg^-1和6 g·kg^-1胶质芽孢杆菌下活性显著增强(P<0.05);多酚氧化酶活性随施用胶质芽孢杆菌浓度上升而持续减弱且变化显著(P<0.05)。研究表明,25 mg·kg^-1Cd处理下施用6 g·kg^-1胶质芽孢杆菌可有效提高蜀葵修复土壤Cd污染的能力,蜀葵-胶质芽孢杆菌联合修复土壤Cd污染具有一定应用潜力。

Remediation of cadmium contamination in soil by Althaea rosea-Bacillus mucilaginosus

The aim of the study was to explore the effect of Bacillus mucilaginosus on the ability of Althaea rosea to remediate Cd contamination in soil. A pot experiment was conducted to study the effects of Bacillus mucilaginosus on biomass, Cd accumulation, available Cd content in rhizosphere soil, and enzyme activities in rhizosphere soil under 25 mg·kg^-1 Cd stress. The results indicated that compared to treatment with Cd alone, under 25 mg·kg^-1 Cd stress, application of 6 g·kg^-1 B. mucilaginosus could significantly increase root and stem biomass (P<0.05)and increased total biomass by 33.6%~73.2%. Cd accumulation in A. rosea was 1.64, 2.89, and 1.69 times higher than that with Cd treatment alone when applied with 3, 6, and 9 g·kg^-1 B. mucilaginosus, respectively. Available Cd content in rhizosphere soil increased significantly after application of different concentrations of bacterial fertilizer (P<0.05). The activity of urease, invertase, and dehydrogenase in rhizosphere soil of A. rosea was significantly increased by application of bacterial fertilizer (P<0.05); however, the activity of polyphenol oxidase continued to decrease and changed significantly (P<0.05). The results showed that the application of B. mucilaginosus under 25 mg·kg^-1 Cd treatment could effectively improve the ability of A. rosea to remediate soil Cd pollution, and the best concentration of bacterial fertilizer was 6 g·kg^-1. Remediation of Cd contamination in soil by Althaea rosea-Bacillus mucilaginosus has application potential.