Cereal Stem Stress: In Situ Biomechanical Characterization of Stem Elasticity

D Jo Heuschele,Taina Acevedo Garcia,Joan Barreto Ortiz,Kevin P Smith,Peter Marchetto

doi:10.3390/app10227965

D Jo Heuschele, Taina Acevedo Garcia + Show 3 more

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https://doi.org/10.3390/app10227965

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Abstract

Stem lodging is the bending or breakage of stems in the wind that result in negative economic impacts to producers and processors of small grain crops. To address this issue, plant breeders attempt to quantify lodging using proxy traits such as stem structure and biomechanics. Stem lodging is a function of both stem strength and elasticity. In this paper, we explore the biomechanics of stems approaching the lodging, or permanent bending, condition. Oat, wheat, and two types of barley varying in lodging resistance were exposed to standard growing conditions over the course of a season. Their capability of returning from a bent to unbent state was characterized using a push force meter that measured resistant force and displacement over time. Changes in stem energy and power were then calculated using displacement and force measurements. Lodging susceptibility could be differentiated by stem strength, displacement and change in power measurements depending on small grain species without damaging the plant. These measurements could be used by small cereal grain breeding programs as proxy traits to determine lodging susceptibility without destructively testing or waiting for storm events, thus saving time and resources.

Highlights

Lodging is a complex trait in which both external and internal forces contribute to overall change in plant structural integrity
One limitation of this method is that weather events with wind speeds that are either too low or too high will not reveal phenotypic variation for lodging among breeding lines and limit the selection that can be imposed by the breeder [1]
The original in situ meter, after extensive experimentation, was only capable of determining push force reliably at between 40 and 70 degrees [7], which has been shown to be predictive of lodging resistance in wheat [7,8] and oat [11], where stronger stems equated to better lodging resistance

Summary

Introduction

Lodging is a complex trait in which both external and internal forces contribute to overall change in plant structural integrity. A stem that is too rigid is at risk of becoming unanchored from the substrate via root slippage (root lodging) or buckling somewhere along the stem (stem lodging). Plant breeders currently screen for lodging resistance using a visual rating scale to quantify the degree to which lodging occurs after weather events with strong winds. One limitation of this method is that weather events with wind speeds that are either too low or too high will not reveal phenotypic variation for lodging among breeding lines and limit the selection that can be imposed by the breeder [1]. Since weather events are stochastic in nature, for years researchers have been attempting

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