Genetic Dissection of Yield-Related Traits in a Set of Maize Recombinant Inbred Lines Under Multiple Environments Agronomic advancements have led to significant increases in maize yield per hectare in Northeast China, primarily through improved density tolerance. However, the genetic mechanism underlying grain yield responses to density stress remains poorly understood. Here, a population of 193 recombinant inbred lines (RILs) derived from the cross between ZM058 and PH1219 was employed to identify quantitative trait loci (QTLs) under two planting densities across three locations over two years. Six yield-related traits were investigated: ear tip-barrenness length (BEL), cob diameter (CD), ear diameter (ED), ear length (EL), kernel number per row (KNR), and kernel row number (KRN). These traits exhibited distinct and divergent responses to density stress, with the values of CD, ED, EL, KNR and KRN decreasing as planting density increased, except for BEL. A total of 81 QTLs were id...