Genome-Wide Association Analysis for the Genetic Basis of Seven Traits Associated with Corn Grain Moisture and Ear Threshing Rate

Maize is an important food and economic crop around the world. Grain moisture is an important trait for maize harvest and generally easier to thresh low-moisture grains. In this study, eight agronomic traits, including cob hardness, cob lignin layer thickness, cob percentage of lignin layer, cob diameter, bract length, bract number, thickness and compaction, were selected which associated with maize grain moisture and threshing rate based on field investigation and analyzed seven traits in 80 elite inbred lines planted in two environments (Changchun, Jilin Province and Dandong, Liaoning Province) in 2015 and 2016. Total 76 single nucleotide polymorphism (SNPs) and 41 candidate genes significantly associated with the above seven agronomic traits (P < 1.0 x 10(-6)) through a genome-wide association study involving 1,490,007 high-quality SNPs were identified. Finally, RT-PCR expression of 19 of the 41 candidate genes in samples with extreme traits was observed. 10 candidate genes were up-regulated expressed in high value samples and nine candidate genes down-regulated expressed in low value samples. This study highlights the genetic architecture of seven traits in corn cobs and bracts which identified potential target genes associated with maize grain moisture and ear threshing rate. (C) 2019 Friends Science Publishers