QTL mapping and phenotypic variation for root architectural traits in maize (Zea mays L.)

• Published in: Theoretical and applied genetics Vol. 127; no. 11; pp. 2293 - 2311
• Main Authors: Burton, Amy L, Johnson, James M, Foerster, Jillian M, Hirsch, Candice N, Buell, C. R, Hanlon, Meredith T, Kaeppler, Shawn M, Brown, Kathleen M, Lynch, Jonathan P
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.11.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Agriculture; Architecture; Biochemistry; Biomedical and Life Sciences; Biotechnology; branching; Chromosome Mapping; Corn; DNA, Plant - genetics; Genetic aspects; Genetics, Population; genotype; Life Sciences; Original Paper; Phenotype; phenotypic variation; Physiological aspects; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Roots - anatomy & histology; Principal Component Analysis; Quantitative genetics; Quantitative Trait Loci; root systems; roots; Sequence Analysis, DNA; shoots; soil; Zea mays; Zea mays - genetics; United States > US; East Lansing Michigan; Michigan; Lateral Root; Root Length; Quantitative Trait Locus; Total Root Length; Root Trait
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-014-2353-4

KEY MESSAGE: QTL were identified for root architectural traits in maize. Root architectural traits, including the number, length, orientation, and branching of the principal root classes, influence plant function by determining the spatial and temporal domains of soil exploration. To characterize phenotypic patterns and their genetic control, three recombinant inbred populations of maize were grown for 28 days in solid media in a greenhouse and evaluated for 21 root architectural traits, including length, number, diameter, and branching of seminal, primary and nodal roots, dry weight of embryonic and nodal systems, and diameter of the nodal root system. Significant phenotypic variation was observed for all traits. Strong correlations were observed among traits in the same root class, particularly for the length of the main root axis and the length of lateral roots. In a principal component analysis, relationships among traits differed slightly for the three families, though vectors grouped together for traits within a given root class, indicating opportunities for more efficient phenotyping. Allometric analysis showed that trajectories of growth for specific traits differ in the three populations. In total, 15 quantitative trait loci (QTL) were identified. QTL are reported for length in multiple root classes, diameter and number of seminal roots, and dry weight of the embryonic and nodal root systems. Phenotypic variation explained by individual QTL ranged from 0.44 % (number of seminal roots, NyH population) to 13.5 % (shoot dry weight, OhW population). Identification of QTL for root architectural traits may be useful for developing genotypes that are better suited to specific soil environments.