Genetic dissection of maize grain moisture content and dehydration rate using high-density bin mapping in a recombinant inbred line population

Abstract

Maize (Zea mays L.) grain moisture content (GMC) at harvest is a key determinant of seed preservation, grain quality, and drying costs, with the grain dehydration rate (GDR) playing a critical role in determining GMC. This study focused on understanding the genetic basis of GDR by utilizing a recombinant inbred line population of 310 lines derived from PB80 and PHJ65, assessed across three environments with high-density SNP markers. A genetic linkage map spanning 1237.36 cM with 5235 bin markers was constructed, leading to the identification of 23 quantitative trait loci (QTLs) associated with GMC and Area Under the Dry Down Curve (AUDDC) across multiple chromosomes, with several QTLs explaining over 10% of the phenotypic variance. Significant QTLs, including qGMC1.1, qGMC2.2, and qAUDDC2.2, were consistently detected across various environments and developmental stages. Transcriptomic analysis identified 21 candidate genes within these QTL regions, including key transcription factors and metabolism-related genes. These findings contribute to a better understanding of the genetic control of GMC and GDR, may serve as a foundation for future breeding efforts in maize breeding to enhance mechanized production efficiency and reduce post-harvest drying costs.