关键词: 苎麻, 锑胁迫, 生长, 锑富集与转运, 土壤修复

Abstract: The heavy metal pollution, ecological restoration, and safe utilization of farmland in the Lengshuijiang tin mining area of Hunan Province have attracted much attention. It is therefore urgent to identify plant species with high antimony accumulation and enrichment. In this study, a pot experiment was conducted to evaluate the growth and antimony accumulation characteristics of ramie cultivar Zhongzhu No. 1 and wild ramie collected from the tin mining area. Plants were subjected to five antimony concentrations (0, 500, 1000, 2000, and 3000 mg·kg^-1). The results showed that the growth of ramie plants was significantly promoted when treated with antimony concentration ≤1000 mg·kg^-1 in Zhongzhu No. 1 and ≤2000 mg·kg^-1 in wild ramie. Higher antimony stress inhibited plant growth, with Zhongzhu No. 1 being more sensitive. Antimony stress led to varying degrees of reduction in SPAD values in leaves of two types of ramie, with Zhongzhu No. 1 showing a significant effect when antimony treatment was ≤1000 mg·kg^-1. With the increases of antimony concentrations, the antimony content in the whole plants of Zhongzhu No. 1 and wild ramie continued to increase, and reached a maximum of 691.46 and 360.40 mg·kg^-1, respectively. The bioaccumulation factor of antimony gradually decreased with increasing antimony stress, with ranges of 0.24-0.76 and 0.13-0.25 for Zhongzhu No. 1 and wild ramie, respectively, while the translocation factor gradually increased, with ranges of 0.10-0.45 and 1.12-1.76, respectively. Zhongzhi No. 1 possessed the characteristic of high antimony content and accumulation in roots, making it suitable for the phytoremediation of antimony-contaminated soil through root uptake and fixation. In contrast, wild ramie exhibited low antimony uptake and accumulation in roots, showing strong adaptability and tolerance under high antimony concentration, and its antimony accumulation ability continued to increase with increasing antimony stress, with a translocation factor being higher than 1. Our findings suggest that both types of ramie can be used as preferred plants for soil remediation in antimony-contaminated mining areas.

Key words: ramie, antimony stress, growth, antimony enrichment and transport, soil remediation