Nitrogen Use Efficiency and the Genetic Variation of Maize Expired Plant Variety Protection Germplasm

Adriano Mastrodomenico,C Hendrix,Frederick Below

doi:10.3390/agriculture8010003

Adriano Mastrodomenico, C Hendrix + Show 1 more

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https://doi.org/10.3390/agriculture8010003

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Journal: Agriculture	Publication Date: Jan 1, 2018
Citations: 14	License type: CC BY 4.0

Affiliation: University of Illinois Urbana-Champaign

Abstract

Nitrogen use efficiency (NUE) in maize (Zea mays L.) is an important trait to optimize yield with minimal input of nitrogen (N) fertilizer. Expired Plant Variety Protection (ex-PVP) Act-certified germplasm may be an important genetic resource for public breeding sectors. The objectives of this research were to evaluate the genetic variation of N-use traits and to characterize maize ex-PVP inbreds that are adapted to the U.S. Corn Belt for NUE performance. Eighty-nine ex-PVP inbreds (36 stiff stalk synthetic (SSS), and 53 non-stiff stalk synthetic (NSSS)) were genotyped using 26,769 single-nucleotide polymorphisms, then 263 single-cross maize hybrids derived from these inbreds were grown in eight environments from 2011 to 2015 at two N fertilizer rates (0 and 252 kg N ha−1) and three replications. Genetic utilization of inherent soil nitrogen and the yield response to N fertilizer were stable across environments and were highly correlated with yield under low and high N conditions, respectively. Cluster analysis identified inbreds with desirable NUE performance. However, only one inbred (PHK56) was ranked in the top 10% for yield under both N-stress and high N conditions. Broad-sense heritability across 12 different N-use traits varied from 0.11 to 0.77, but was not associated with breeding value accuracy. Nitrogen-stress tolerance was negatively correlated with the yield increase from N fertilizer.

Highlights

World-wide, producers used approximately 109 million tons of nitrogen (N) fertilizer in 2014 [1].Of that amount, more than 5 million tons are used for maize (Zea mays L.) production in the UnitedStates (U.S.) [2]
Genetic utilization of inherent soil nitrogen and the yield response to N fertilizer were stable across environments and were highly correlated with yield under low and high N conditions, respectively
Nitrogen is the mineral macronutrient required in the greatest amount by the maize crop, with uptake values being measured at 280 kg N ha−1 for a crop producing 14.4 Mg ha−1 of grain [3]

Summary

Introduction

World-wide, producers used approximately 109 million tons of nitrogen (N) fertilizer in 2014 [1].Of that amount, more than 5 million tons are used for maize (Zea mays L.) production in the UnitedStates (U.S.) [2]. The maize yield increases observed, despite the constant N fertilizer consumption in the United States during the last two decades, were a result of both genetic improvement and better agronomic practices [4]. The world population growth will require increased grain production, and more N fertilizer efficiency will be necessary to meet the world’s demand [6]. Innovative agricultural technologies, such as new N fertilizer sources, precision agriculture, and crop genetic improvement will be important to increase nitrogen use efficiency in maize production [7]. Belt with more recently recently expired PVP certificates from a selection of seed companies were included.

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Conclusion