Integrated Puncture Score: force–displacement weighted rind penetration tests improve stalk lodging resistance estimations in maize

Abstract

Background: Stalk lodging (breaking of agricultural plant stalks prior to harvest) is a multi-billion dollar a year problem. Rind penetration resistance tests have been used by plant scientists and breeders to estimate the stalk lodging resistance of maize for nearly a hundred years. However, the rind puncture method has two key limitations: (1) the predictive power of the test decreases significantly when measuring elite or pre-commercial hybrids, and (2) using rind penetration measurements as a breeding metric does not necessarily create stronger stalks. In this study, we present a new rind penetration method called the Integrated Puncture Score, which uses a modified rind penetration testing protocol and a physics-based model to provide a robust measure of stalk lodging resistance. Results: Two datasets, one with a diverse array of maize hybrids and one with only elite hybrids, were evaluated by comparing traditional rind penetration testing and the Integrated Puncture Score method to measurements of stalk bending strength. When evaluating the diverse set of hybrids, both methods were good predictors of stalk bending strength (R 2 values of 0.67). However, when evaluating elite hybrids, the Integrated Puncture Score had an R 2 value of 0.74 whereas the traditional method had an R 2 value of 0.48. Additionally, the Integrated Puncture Score was able to differentiate between the strongest and weakest hybrids in the elite hybrid data set whereas the traditional rind penetration method was not. Additional experiments revealed strong evidence in favor of the data aggregation steps utilized to compute the Integrated Puncture Score. Conclusions: This study presents a new method for evaluating rind penetration resistance that highly correlates with stalk bending strength and can possibly be used as a breeding index for assessing stalk lodging resistance. This research lays the foundation required to develop a field-based high-throughput phenotyping device for stalk lodging resistance.

Asian corn borer damage is affected by rind penetration strength of corn stalks in a spatiotemporally dependent manner

“…Stalk strength is a physical barrier against larval boring (Butrón et al, 2002 ; Suby et al, 2020 ); however, previous studies on stalk strength in maize have often focused on its relationship with stalk lodging (Feng et al, 2010 ; Flint‐Garcia et al, 2003 ; Gibson et al, 2009 ; Kamran et al, 2018 ; Kvedaras & Keeping, 2007 ; Liu et al, 2011 ; Ma et al, 2014 ; Robertson et al, 2017 ; Sekhon et al, 2020 ; Stubbs et al, 2020 ) or colonization of fungal pathogens, such as Diplodia zeae (Schweinitz) (Chambers, 1987 ) and Gibberella zeae (Schweinitz) (Pe et al, 1993 ). Stalk strength usually is measured by bending, puncturing or crushing the rind, or by measuring rind thickness (Thompson, 1963 ).…”

Biomechanical phenotyping pipeline for stalk lodging resistance in maize

“…The methods file used to run the Instron software is available as supplementary material. These files were then analyzed using an integrative puncture score algorithm [13 , 17] which calculated minor diameter, integrated puncture score, rind thickness, and maximum puncture force (also known as rind penetration resistance). Fig.…”

High-Throughput Phenotyping of Cross-Sectional Morphology to Assess Stalk Mechanical Properties in Sorghum

“…Many studies have indicated that stem-related traits, such as basal internode length and thickness, stem wall thickness, leaf sheath covering and thickness, contribute to culm strength and lodging resistance [38,45]. In maize, it was reported that the cross-sectional morphology of stalks, such as rind thickness and diameter are key determinants of stalk bending strength and lodging resistance [19,[28][29][30]. Efforts to understand the mechanism of lodging and to improve stem strength and its related components should be an im- Many studies have indicated that stem-related traits, such as basal internode length and thickness, stem wall thickness, leaf sheath covering and thickness, contribute to culm strength and lodging resistance [38,45].…”

“…Efforts to understand the mechanism of lodging and to improve stem strength and its related components should be an im- Many studies have indicated that stem-related traits, such as basal internode length and thickness, stem wall thickness, leaf sheath covering and thickness, contribute to culm strength and lodging resistance [38,45]. In maize, it was reported that the crosssectional morphology of stalks, such as rind thickness and diameter are key determinants of stalk bending strength and lodging resistance [19,[28][29][30]. Efforts to understand the mechanism of lodging and to improve stem strength and its related components should be an important focus in future sorghum breeding for lodging resistance.…”

“…Several previous studies have focused on the anatomical features associated with lodging resistance in maize [26,27]. The cross-sectional morphology of stalks including rind thickness and diameter were reported as the key determinants of stalk bending strength and lodging resistance in maize [19,[28][29][30]. The thickness of sclerenchyma is positively correlated with lodging resistance [31][32][33].…”