Identification of Peanut Cultivars with Low Cadmium Contents and Their Rhizosphere Microbial Characteristics in Alkaline and Acidic Cadmium-Contaminated Fields

Employing crop cultivars with low cadmium (Cd) accumulation and high yield is an effective strategy for the sustainable and safe utilization of Cd-contaminated farmland. However, the current understanding of peanut cultivars, particularly under field conditions, is limited. This study identified low-Cd cultivars and their rhizosphere microbial characteristics in acidic and alkaline fields with moderate Cd contamination. The results indicated that cultivars LH11, FH1, LH14, and YH9414 exhibited low Cd accumulation and high yield, with kernel Cd content reduced by 27.27% to 47.28% and yield increased by 9.27% to 14.17% compared with cultivar SLH. Among them, FH1 was validated to achieve safe production in two fields. A unique microbial community was formed by the recruitment of diverse microbes, such as Alphaproteobacteria, Acidobacteria, Gemmatimonadetes, and Chloroflexi, to the rhizosphere soil of FH1, which might be associated with Cd immobilization and the promotion of plant growth. Functional predictions further validated these findings, revealing enhanced functional pathways in the FH1 rhizosphere related to microbial proliferation, Cd stabilization, and detoxification. This study provides valuable germplasm resources for safe agriculture of Cd-polluted soils and elucidates the rhizosphere microbial characteristics of different peanut cultivars under field conditions. These findings are important for the targeted management of contaminated farmland and ensuring safe food production.