The heavy metals lead and cadmium have become important pollutants in the environment, which exert negative effects on plant morphology, growth and photosynthesis. It is particularly significant to uncover the genetic loci and the causal genes for lead and cadmium tolerance in plants. This study used an IBM Syn10 DH population to identify the quantitative trait loci (QTL) controlling maize seedling tolerance to lead and cadmium by linkage mapping. The broad-sense heritability of these seedling traits ranged from 65.8–97.3% and 32.0–98.8% under control (CK) and treatment (T) conditions, respectively. A total of 53 and 64 QTL were detected under CK and T conditions, respectively. Moreover, 42 QTL were identified using lead and cadmium tolerance coefficient (LCTC). Among these QTL, five and two major QTL that explained > 10% of phenotypic variation were identified under T condition and using LCTC, respectively. Furthermore, eight QTL were simultaneously identified by T and LCTC, explaining 5.23% to 9.21% of the phenotypic variations. Within these major and common QTL responsible for the combined heavy metal tolerance, four candidate genes (Zm00001d048759, Zm00001d004689, Zm00001d004843, Zm00001d033527) were previously reported to correlate with heavy metal transport and tolerance. These findings will contribute to functional gene identification and molecular marker-assisted breeding for improving heavy metal tolerance in maize.

重金属铅和镉已成为环境中的重要污染物，对植物形态、生长和光合作用产生负面影响。揭示植物耐铅镉的遗传位点和致病基因具有特别重要的意义。本研究使用 IBM Syn10 DH 群体通过连锁作图确定控制玉米幼苗对铅和镉的耐受性的数量性状基因座 (QTL)。在对照（CK）和处理（T）条件下，这些幼苗性状的广义遗传力分别为 65.8-97.3% 和 32.0-98.8%。在CK和T条件下分别检测到53个和64个QTL。此外，使用铅镉耐受系数（LCTC）鉴定了42个QTL。在这些QTL中，解释了五个和两个主要的QTL > 分别在 T 条件下和使用 LCTC 鉴定了 10% 的表型变异。此外，T 和 LCTC 同时鉴定了 8 个 QTL，解释了 5.23% 至 9.21% 的表型变异。在这些负责联合重金属耐受性的主要和常见 QTL 中，有四个候选基因（Zm00001d048759、Zm00001d004689、Zm00001d004843、Zm00001d033527 ) 之前被报道与重金属运输和耐受性相关。这些发现将有助于功能基因鉴定和分子标记辅助育种，以提高玉米的重金属耐受性。