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Check, J. C.

Publications and source records attributed to Check, J. C..

3 recordsLinked to original sources

An industry perspective on whole genome-informed hybrid maize disease resistance characterization to improve breeding decisions

Characterizing hybrid maize disease resistance is a costly and labor-intensive effort in commercial breeding programs. Field trials are carefully inoculated and managed but remain error-prone due to spatial variability in disease pressure, microclimatic conditions and inter-rater variability. Quantitative ordinal disease rating scales are used to increase scoring speed at the expense of resolution, accuracy, and the ability to use conventional statistical methods. To improve traditional methods of disease resistance characterization, we propose to leverage readily available low-density SNP marker profiles to create genome-informed disease scores. Specifically, a whole genome ordered probit regression (WGOPR) model is used to deconstruct field-observed disease phenotypes into marker effects and reconstruct genome-informed disease scores. This approach is demonstrated in hybrid maize using data from Exserohilum turcicum-inoculated field trials across the central and northern U.S. and Canadian Corn Belt in 2024. Resulting Genomic Estimated Categorical Probabilities (GECPs) are compared to observed frequencies of disease scores to validate the methodology and evaluate the accuracy of regional hybrid maize disease resistance characterization. The benefit of a probabilistic output is demonstrated through two use cases: a comparison of hybrids with highly variable observed disease resistance scores at a single location, and a comparison of breeding selection schemes from a regional analysis. Because GECPs are the product of estimated marker effects, they better represent the expected behavior of a genotype independent of location-, rater- and plot-specific noise, and will therefore offer a step towards improving hybrid maize characterization and better informing breeding decisions.

pathology↗

The Euler Characteristic Transform Enables Classification of Complex Plant Shapes and Prediction of Leaf Venation from Blade Geometry

(1) RationaleQuantifying and predicting plant morphology is central to understanding development and evolution, yet many plant forms lack homologous features required for traditional morphometrics. We apply the Euler Characteristic Transform (ECT), an injective descriptor from topological data analysis, to encode 2D plant shapes. The ECT converts contours into image-like representations that preserve shape information while enabling deep learning. (2) MethodsWe computed ECTs for large datasets of leaf and pavement cell shapes and used convolutional neural networks (CNNs) for classification. We also trained CNNs to approximate the inverse mapping, predicting leaf shape masks from radial ECTs. (3) Key resultsECT-based models achieved high classification accuracy, surpassing previous approaches on millions of herbarium-derived leaves. Notably, grapevine leaf venation was predicted from blade geometry alone, demonstrating that vascular structure is encoded in the outline. (4) Main conclusionThe ECT provides a compact, information-preserving representation of biological shape that integrates naturally with deep learning. It enables both accurate classification and predictive reconstruction, revealing latent morphological information and offering new opportunities to study plant form across scales.

plant biology↗

Uncovering the Environmental Conditions Required for Phyllachora maydis Infection and Tar Spot Development on Corn in the United States for Use as Predictive Models for Future Epidemics

Phyllachora maydis is a fungal pathogen causing tar spot of corn (Zea mays L.), a new and emerging, yield-limiting disease in the United States. Since being first reported in Illinois and Indiana in 2015, P. maydis can now be found across much of the corn growing of the United States. Knowledge of the epidemiology of P. maydis is limited but could be useful in developing tar spot prediction tools. The research presented here aims to elucidate the environmental conditions necessary for the development of tar spot in the field and the creation of predictive models to anticipate future tar spot epidemics. Extended periods (30-day windowpanes) of moderate ambient temperature were most significant for explaining the development of tar spot. Shorter periods (14- to 21-day windowpanes) of moisture (relative humidity, dew point, number of hours with predicted leaf wetness) were negatively correlated with tar spot development. These weather variables were used to develop multiple logistic regression models, an ensembled model, and two machine learning models for the prediction of tar spot development. This work has improved the understanding of P. maydis epidemiology and provided the foundation for the development of a predictive tool for anticipating future tar spot epidemics.

plant biology↗