关键词: 重金属, 吸收, 迁移, 稻米, 根际

Abstract: Cadmium (Cd) is a common heavy metal pollutant, which has a serious toxic effect on the growth and development of rice. Consumption of rice is the main way of Cd intake for human. Although the accumulation of Cd in rice has attracted global attention, little is known about the effects of arbuscular mycorrhizal fungi (AMF), one of the microorganisms most closely related to the rhizosphere, on the accumulation of Cd in rice. In this study, Glomus mosseae 171 (GM171) and G. mosseae 180 (GM180) were selected to examine their effects on rice growth (plant height, root length, biomass), Cd concentration in pore water, and Cd concentration in different tissues of rice (root, stalk, leaf, seed, hull, bran) at different growth stages in a pot experiment. Results showed that inoculation of GM171 and GM180 did not affect plant height, root length and biomass of rice. Different AMF strains had different effects on Cd concentration in pore water at different rice growth stages. AMF inoculation significantly promoted Cd accumulation in both the underground and aboveground tissues of rice. Compared with CK, inoculation with GM171 and GM180 increased root Cd concentration by 27% and 11%, respectively, and increased grain Cd concentration by 28% and 24%, respectively. The root contained the largest proportion of Cd in the whole plant, reaching to ≥50%. In summary, AMF inoculation promoted the absorption of Cd by rice roots and the migration of Cd to the aboveground tissues, resulting in increasing Cd concentration in the aboveground tissues and higher health risk to human. This study provides scientific reference for the remediation of Cd pollution in croplands.

Key words: heavy metal, absorption, translocation, rice, rhizosphere