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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #272871
Title: Changes in kernel filling with selection for grain yield in a maize population

Author
item EICHENBERGER, STEVEN - Iowa State University
item MIZUEZ, FERNANDO - Iowa State University
item Edwards, Jode
item KNAPP, ALLEN - Iowa State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2014
Publication Date: 3/20/2015
Citation: Eichenberger, S., Mizuez, F., Edwards, J.W., Knapp, A. 2015. Changes in kernel filling with selection for grain yield in a maize population. Crop Science. 55:521-526. DOI: 10.2135/cropsci2014.07.0462.

Interpretive Summary: Hybrid maize grain yields in the U.S. have increased from approximately 1.5 Mg Ha-1 to 8.5 Mg Ha-1. Demand for corn continues to increase, and thus sustained increased in grain yield are needed to meet both food and fuel needs. Substantial increases in grain yield will require an understanding of factors that limit grain yield and factors that have contributed to increases observed in the past. In a direct study of long-term selection in corn at different plant densities, we found that improved maize populations had a longer period of grain fill across plant density that was unaffected by hybrid vigor. This research demonstrates the important contribution of maintaining a healthy maize leaf canopy for grain fill throughout the growing season which includes adapted hybrids, disease resistance, and water and nutrient availability throughout the season. This information will be used by agronomists and breeders to develop improved hybrids and production practices to meet future demand for corn.

Technical Abstract: Hybrid maize yield increases, new product development, and increased stress tolerance can be more easily achieved with a better understanding of the physiological and genetic basis for phenotypic changes in response to recurrent selection for yield. The purpose of this study was to identify changes in grain fill characteristics and their interaction with plant density in a closed population and identify a model that accurately predicts grain fill in this population. We hypothesize that recurrent selection for increased yield indirectly impacted the grain fill characteristics of maize including final kernel weight, kernel fill duration, and kernel fill rate in the Iowa Stiff Stalk Synthetic maize population. We also hypothesize that recurrent selection for yield has indirectly improved maize tolerance to high plant density stress for these grain fill characteristics. Populations representing different levels of advancement from the Iowa Stiff Stalk Synthetic maize population were compared to at two different locations near Ames, Iowa in 2009 and 2010. Populations were compared at plant densities of 5.3 and 7.7 seeds m-2. Treatments were replicated three times per location in a split plot design. Recurrent selection for yield has led to changes in final kernel weight and kernel fill duration, as well as the response of kernel weight to increased planting densities. This supports our hypothesis that recurrent selection for yield changed grain fill characteristics and the effect of high plant density stress in the Iowa Stiff Stalk Synthetic maize population. The rate of kernel fill was not affected by recurrent selection for yield in the Iowa Stiff Stalk Synthetic maize population.