In a groundbreaking advance that fuses traditional crop modeling, genomic science, and machine learning, researchers have unveiled a sophisticated approach to predicting rice flowering time with unprecedented accuracy and robustness. This novel method integrates three established rice growth simulation models—ORYZA, CERES-Rice, and RiceGrow—with genome-wide association studies (GWAS), single nucleotide polymorphism (SNP)-based genomic predictions, and climate indices to create a powerful genotype-environment interaction (G×E) prediction framework. Published on February 25, 2025, in the open-access journal Plant Phenomics, this study spearheaded by Liang Tang’s team at Nanjing Agricultural University signals a transformative shift in precision agriculture and molecular breeding strategies.

Crop phenology, particularly flowering time, plays a vital role in determining rice yield and adaptability, especially under the increasing volatility introduced by climate change. Traditional process-based models effectively simulate plant growth dynamics by incorporating environmental factors such as temperature and photoperiod, yet they often fail to capture the intricate genetic architecture and complex nonlinear interactions governing flowering time across diverse genotypes and environments. Addressing this critical gap, Tang and colleagues leveraged genomic data to estimate genotype-specific parameters (GSPs) within crop models, thereby providing a mechanistic link between genotype and phenotype. However, the intrinsic complexity and nonlinearities in these interactions posed substantial challenges, limiting the predictive power of existing models when used in isolation.

The research team conducted a meticulous integration of multiple modeling layers. Initially, they estimated GSPs for each genotype within the three process-based models—ORYZA, CERES-Rice, and RiceGrow. They observed that key parameters related to photoperiod and temperature sensitivity exhibited both unimodal and bimodal distributions, reflecting considerable genetic diversity. Variability metrics such as coefficients of variation exceeded 60% for parameters like PhotoDCERES and IntriERiceGrow, indicative of the nuanced differentiation in genotypic response to environmental cues. Correlational analyses revealed substantial agreement among photoperiod-related parameters across the distinct crop models, underscoring that despite differences in model structure, key physiological sensitivities are consistently captured.

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On evaluating model performance, the researchers reported impressive accuracy in predicting flowering times using GSP-fitted models. Root mean square errors (RMSEs) ranged from 10.11 to 21.25 days, and Pearson correlation coefficients reached as high as 0.94, demonstrating strong congruence between observed and predicted phenotypes. Despite this progress, when SNP-based genomic predictions directly estimated GSPs via ridge regression and rr-BLUP methods, prediction accuracy initially declined. Notably, ridge regression surpassed rr-BLUP in predictive efficacy, particularly within test datasets, suggesting that penalized regression techniques may better handle the high-dimensional genomic data inherent in this context.

To enhance the predictive performance compromised by genomic estimation errors, the research introduced a secondary modeling stage harnessing state-of-the-art machine learning. Among various algorithms tested, XGBoost—a gradient boosting framework—emerged as the optimal choice to correct residual prediction errors. This ensemble learning approach effectively captured nonlinear G×E interactions and interactions within the genomic data, complementing the underlying mechanistic crop models. The integration of climate indices further elevated the model’s predictive capability; notably, growing degree days (GDD) measured 100 days post-sowing consistently surfaced as the most influential environmental variable across models, reinforcing its utility in phenological modeling.

An innovative feature of the study was the adoption of a multi-model ensemble (MME) strategy, whereby outputs from the three distinct crop models were combined. This ensemble approach yielded robust and stable predictions consistently on par with or surpassing the best-performing individual models. Such a strategy mitigates model-specific biases and leverages complementary strengths inherent in different simulation algorithms. Collectively, this multi-layered framework—spanning mechanistic crop modeling, genomic prediction, climate-informed machine learning, and model ensembles—constitutes a pioneering schema that enhances both the interpretability and transferability of phenotype predictions.

Beyond the immediate gains in predictive accuracy, the study’s methodology addresses several systemic challenges in modern breeding. The explicit modeling of G×E interactions through genomic-informed crop models facilitates the identification of molecular markers linked to phenotype-relevant parameters. In this context, GWAS pinpointed hundreds of quantitative trait nucleotides (QTNs) associated with particular GSPs. Remarkably, markers proximal to well-characterized flowering genes such as DTH2, DTH3, DTH7, and OsCOL15 were identified, reinforcing the biological validity of the approach and offering tangible targets for marker-assisted selection.

This integrative framework is particularly critical in the context of climate variability and environmental stress. By accurately modeling how specific genotypes respond to dynamic environmental conditions, breeders can tailor selections that optimize flowering time, directly impacting yield stability and resilience. Such precision breeding holds promise not only for rice but also extends to other essential crops confronting similar environmental uncertainties. The scalability and adaptability of this paradigm underline its strategic importance for global food security under the pressures of climate change.

Technical robustness is complemented by the study’s comprehensive experimental design, featuring extensive phenotypic, genomic, and environmental datasets. The use of advanced statistical genomics methods alongside cutting-edge machine learning algorithms exemplifies a data-driven yet biologically grounded approach. The rigorous validation through cross-model correlation, statistical metrics, and biological interpretation enhances confidence in the reproducibility and applicability of the findings.

The authors emphasize that this holistic G×E modeling approach transcends conventional methodologies by coupling biological insight with computational innovation. It enables breeders to move beyond phenomenological predictions towards mechanistically interpretable models that link DNA sequence variation to observable traits across fluctuating environmental gradients. Such interpretability is vital for the practical deployment of predictive breeding tools in decision-making processes, accelerating the development pipeline from lab to field.

In conclusion, the study by Liang Tang’s team presents a transformative pathway that integrates crop physiology, genomics, and environmental data through sophisticated machine learning, culminating in an accurate, interpretable, and transferable prediction system for rice flowering time. This hybrid approach exemplifies the future of precision agriculture, charting a course for molecular breeding programs to harness genomic and environmental complexity in a predictive, scalable manner. As climate challenges intensify, such innovations are poised to become indispensable in sustaining crop productivity and food security worldwide.

Subject of Research: Not applicable
Article Title: Integrating crop models, single nucleotide polymorphism, and climatic indices to develop genotype-environment interaction model: A case study on rice flowering time
News Publication Date: 25-Feb-2025
Web References: http://dx.doi.org/10.1016/j.plaphe.2025.100007
References: 10.1016/j.plaphe.2025.100007
Keywords: Applied sciences and engineering, Agriculture, Engineering

Tags: climate impact on rice growthcrop modeling and genomicsflowering time and climate changegenomic predictions in breedinggenotype-environment interactionGWAS and rice yieldmachine learning in agricultureNanjing Agricultural University researchORYZA and CERES-Rice modelsprecision agriculture advancementsrice flowering predictionSNP-based genetic analysis