ABSTRACT

To evaluate the effects of cabbage varieties and PGPR inoculation on the mobility and phytoavailability of Pb and Cd in a contaminated soil, a factorial (3 × 6) pot experiment with completely randomized design and three replications was performed. The cabbage varieties were ornamental cabbage, broccoli and cabbage and the PGPR strains included Pseudomonas putida PTCC1694, Bacillus megaterium PTCC1656, Azotobacter chroococcum, Proteus vulgaris PTCC1079 and Bacillus subtilis PTCC1715. The results indicate that the PGPR inoculation increased the amounts of plant biomass, the Pb and Cd concentrations in the root and shoot, the Pb and Cd uptake performances, the mobility, phytoavailability and translocation factor. The Pb bound to Fe-Mn oxides (42.7%) and the Cd bound to carbonate (38.1%) were the predominant heavy metal fractions. The percentages of the Pb and Cd in the soluble, exchangeable and organic matter-bound fractions increased while those of the Pb and Cd in the carbonate and Fe-Mn oxide-bound fractions decreased by lowering the soil pH and increasing the concentration of dissolved organic carbon (DOC). It is concluded that inoculation of heavy metal contaminated soils by the PGPR strains, especially Bacillus megaterium PTCC1656, enhances the phytoremediation process by increasing the metal phytoavailability and biomass production of the plant.

Abbreviations

HMe: Heavy metals; PGPR: Plant growth-promoting rhizobacteria; DOC: Dissolved organic carbon; HCN: Hydrogen cyanide; IAA: Indole-3-acetic acid; MIC: Minimum Inhibitory Concentrations; LB: Liquid broth; EC: Electrical conductivity; OC: Organic carbon; FC: Field capacity; WS: Water soluble; EX: Exchangeable; CAR: Bound to carbonates; OX: Bound to Fe-Mn oxides; OM: Bound to organic matter; RES: Residual; BOA: Ornamental cabbage; BOC: Cabbag; BOI: Broccoli; Pp: Pseudomonas putida PTCC1694; Bm: Bacillus megaterium 107 PTCC1656; Ac: Azotobacter chroococcum; Pv: Proteus vulgaris PTCC1079; Bs: Bacillus subtilis 108 PTCC1715; C^-: Uninoculated non-rhizosphere soil; C⁺: Uninoculated rhizosphere soil; TF: Translocation factor; MF: Mobility factor; ANOVA: Analysis of variance

摘要

为了评估卷心菜品种和 PGPR 接种对污染土壤中 Pb 和 Cd 的迁移率和植物有效性的影响，进行了完全随机设计和 3 次重复的因子 (3 × 6) 盆栽试验。卷心菜品种为观赏卷心菜、西兰花和卷心菜，PGPR菌株包括恶臭假单胞菌PTCC1694、巨大芽孢杆菌PTCC1656、Azotobacter chroococcum、Proteus vulgaris PTCC1079和Bacillus subtilisPTCC1715。结果表明，接种PGPR增加了植物生物量、根和茎中Pb和Cd浓度、Pb和Cd吸收性能、迁移率、植物有效性和易位因子。与 Fe-Mn 氧化物结合的 Pb (42.7%) 和与碳酸盐结合的 Cd (38.1%) 是主要的重金属成分。随着土壤 pH 值的降低和溶解有机物浓度的增加，可溶性、可交换性和有机物结合部分中 Pb 和 Cd 的百分比增加，而碳酸盐和 Fe-Mn 氧化物结合部分中 Pb 和 Cd 的百分比降低碳 (DOC)。得出的结论是，PGPR菌株，尤其是巨大芽孢杆菌对重金属污染土壤的接种PTC1656 通过增加植物的金属植物有效性和生物量产量来增强植物修复过程。

缩写

HMe：重金属；PGPR：促进植物生长的根际细菌；DOC：溶解有机碳；HCN：氰化氢；IAA：吲哚-3-乙酸；MIC：最低抑制浓度；LB：液体肉汤；EC：电导率；OC：有机碳；FC：现场容量；WS：水溶性；例如：可交换；CAR：与碳酸盐结合；OX：与 Fe-Mn 氧化物结合；OM：与有机物结合；RES：残差；BOA：观赏白菜；BOC：卡包；BOI：西兰花；Pp：恶臭假单胞菌PTCC1694；Bm：巨大芽孢杆菌107PTCC1656；Ac：Azotobacter chroococcum；PV ：普通变形杆菌PTCC1079；Bs：枯草芽孢杆菌108 PTCC1715；C ^-：未接种的非根际土壤；C ⁺: 未接种的根际土壤；TF：易位因子；MF：流动因子；ANOVA：方差分析