Genome-wide association analysis of plant architecture traits using doubled haploid lines derived from different cycles of the Iowa Stiff Stalk Synthetic maize population

Authors: LEDESMA, ALEJANDRO - Iowa State University; SANTANA, ALICE - Universidade Federal De Vicosa; RIBEIRO, FERNANDO A. - Iowa State University; AUILAR, FERNANDO - Iowa State University; Edwards, Jode; FREI, URSULA - Iowa State University; LUBBERSTEDT, THOMAS - Iowa State University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2023
Publication Date: 12/4/2023
Citation: Ledesma, A., Santana, A.S., Ribeiro, F.S., Auilar, F.S., Edwards, J.W., Frei, U., Lubberstedt, T. 2023. Genome-wide association analysis of plant architecture traits using doubled haploid lines derived from different cycles of the Iowa Stiff Stalk Synthetic maize population. Frontiers in Plant Science. 14. https://doi.org/10.3389/fpls.2023.1294507.
DOI: https://doi.org/10.3389/fpls.2023.1294507

Interpretive Summary: Continued increases in maize grain yield will be needed as demand for grains increases. Most of the improvement in maize grain yield has been the result of improved genetic adaptation to high planting density in maize hybrids. However, few of the specific genetic changes underlying these improvements have been identified. In collaboration with Iowa State University, USDA ARS scientists identified several candidate genes underlying genetic changes that lead to improved maize adaptation to high planting density. The identification of genes for adaptation to high planting density could lead to more efficient genetic approaches to developing higher yielding maize hybrids. This work will benefit maize breeders and geneticists working to improve maize hybrids as well as maize producers and consumers.

Technical Abstract: Selection in the Iowa Stiff Stalk Synthetic (BSSS) maize population for high yield, grain moisture, and root and stalk lodging has indirectly modified plant architecture traits that are important for adaptation to high plant density. In this study, we developed doubled haploid (DH) lines from the BSSS maize population in the earliest cycle of recurrent selection (BSSS), cycle 17 of reciprocal recurrent selection, [BSSS(R)17] and the cross between the two cycles [BSSS/BSSS(R)C17]. We aimed to determine the phenotypic variation and changes in agronomic traits that have occurred through the recurrent selection program in this population and to determine if BSSS DH lines are useful for GWAS to identify genes or regions in the genome associated with the plant architecture changes observed in the different cycles of selection. We conducted a per se evaluation of DH lines focusing on high heritability traits important for adaptation to high planting density and grain yield. Trends for reducing flowering time, anthesis-silking interval, ear height, and the number of primary tassel branches in BSSS(R)17 DH lines compared to BSSS and BSSS/BSSS(R)C17 DH lines were observed. Additionally, the BSSS(R)C17 DH lines showed more upright flag leaf angles. Using the entire panel of DH lines increased the number of SNP markers identified within candidate genes associated with plant architecture traits. DH lines developed from the BSSS maize population are useful for association analysis.