Genome-Wide Association Study Elucidating Key Genetic Determinants of Stalk Water Content in Mature Maize (Zea mays L.)

Background The Stalk Moisture Content (SMC) is an important measure of stem fullness, disease resistance and lodging resistance. Results In this study, 236 inbred lines were used as the basic materials, and the water content of stalk in the third section was determined using the drying method and calibrated probe method for maize were investigated at the tasseling, grain filling, and maturity stages. 461,053 high-quality SNPs obtained through whole-genome resequencing were used for a genome-wide association study. As a result of mixed linear model (MLM, P < 9.94×10 ^− 6 ) analysis, 55 significant SNPs related to traits were detected, explaining 9.11%-15.13% phenotypic variation, among which 22 SNPs were found by the drying method (DMSMC) and 33 SNPs by the calibrated probe method(PMSMC). A total of 7 candidate genes were detected repeatedly, The Zm00001d014449 (detected four times) encodes a chromodomain protein involved in vascular bundle formation. The Zm00001d003476 (detected twice) encodes ubiquitin carboxyl-terminal hydrolase. The Zm00001d005351 gene was associated with the DMSMC2 phase and encodes the synthesis of aromatic acid dehydratase. The Zm00001d025134 gene was a chromosome domain protein, which was found to be related to drought resistance of maize. Conclusions This study helps to deepen the understanding of the genetic basis of maize stalk water content traits, and provides theoretical guidance for screening germplasm materials.