|LARSSON, SARA - Cornell University
|PEIFFER, JASON - North Carolina State University
|ERSOZ, ELHAN - Syngenta Seeds, Inc
|Holland, Jim - Jim
|TUINSTRA, MITCHELL - Purdue University
|ROMAY, MARIA - Cornell University
|Buckler, Edward - Ed
Submitted to: bioRxiv
Publication Type: Review Article
Publication Acceptance Date: 9/7/2017
Publication Date: 9/7/2017
Citation: Larsson, S.J., Peiffer, J.A., Edwards, J.W., Ersoz, E.S., Flint Garcia, S.A., Holland, J.B., Mcmullen, M.D., Tuinstra, M.R., Romay, M.C., Buckler Iv, E.S. 2017. Genetic analysis of lodging in diverse maize hybrids. bioRxiv. https://doi.org/10.1101/185769.
Interpretive Summary: Damage caused by lodging is a significant problem in corn production resulting in estimated annual yield losses of 5-20 percent. Although breeding efforts have increased lodging resistance, this trait is still highly challenging to work with, because it is very difficult to replicate in a controlled setting (i.e., factors such as wind, rain, and insect infestation are not reproducible). In this paper the authors report results from lodging on a diverse set of maize hybrids caused by five naturally occurring weather events. The diversity of the materials evaluated permitted the identification of major regions controlling lodging. Genes influencing stalk and root composition are located in those regions. Moreover, the regions overlapped with those reported in previous studies where indirect measurements for lodging, more repeatable, but in theory less reliable, were used (e.g., stalk strength). The results reported in this paper show relationships between lodging and other important agronomic traits like yield. Additionally, the data point to genes and regions that regulate it and validate the use of indirect methods. All this information constitutes an important resource that breeders can use to improve lodging resistance.
Technical Abstract: Damage caused by lodging is a significant problem in corn production that results in estimated annual yield losses of 5-20 percent. Over the past 100 years, substantial maize breeding efforts have increased lodging resistance by artificial selection. However, less research has focused on understanding the genetic architecture underlying lodging. Lodging is a problematic trait to evaluate since it is greatly influenced by environmental factors such as wind, rain, and insect infestation, which make replication difficult. In this study over 1,723 diverse inbred maize genotypes were crossed to a common tester and evaluated in five environments over multiple years. Natural lodging due to severe weather conditions occurred in all five environments. By testing a large population of genetically diverse maize lines in multiple field environments, we detected significant correlations for this highly environmentally influenced trait across environments and with important agronomic traits such as yield and plant height. This study also permitted the mapping of quantitative trait loci (QTL) for lodging. Several QTL identified in this study overlapped with loci previously mapped for stalk strength in related maize inbred lines. QTL intervals mapped in this study also overlapped candidate genes implicated in the regulation of lignin and cellulose synthesis.