Growth Response and Arsenic Uptake of White Clover (Trifolium repens) and Evening Primrose (Oenothera odorata) Colonized with Arbuscular Mycorrhizal Fungi in Arsenic-Contaminated Soil

A greenhouse experiment was conducted to investigate the role of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae (BEG 107) in enhancing growth and arsenic (As) and phosphorus (P) uptake of white clover (Trifolium repens) and evening primrose (Oenothera odorata) in soil collected from a gold mine having concentrations of 381.6 mg total As kg-¹ and 20.5 mg available As kg-¹. Trifolium repens and O. odorata are widely distributed on abandoned metalliferous mines in Korea. The percent root colonization by the AM fungus was 55.9% and 62.3% in T. repens and O. odorata, respectively, whereas no root colonization was detected in control plants grown in a sterile medium. The shoot dry weight of T. repens and O. odorata was increased by 323 and 117% in the AM plants compared to non-mycorrhizal (NAM) plants, respectively. The root dry weight increased up to 24% in T. repens and 70% in O. odorata following AM colonization compared to control plants. Mycorrhizal colonization increased the accumulation of As in the root tissues of T. repens and O. odorata by 99.7 and 91.7% compared to the NAM plants, respectively. The total uptake of P following AM colonization increased by 50% in T. repens and 70% in O. odorata, whereas the P concentration was higher in NAM plants than in the AM plants. Colonization with AM fungi increased the As resistance of the host plants to As toxicity by augmenting the yield of dry matter and increasing the total P uptake. Hence, the application of an AM fungus can effectively improve the phytoremediation capability of T. repens and O. odorata in As-contaminated soil.