A Linear-Transformer Hybrid for SNP-Based Genotype-to-Phenotype Prediction in Grapevine
Predicting complex phenotypes such as grapevine leaf trichome density from SNP data remains challenging in variable field environments and across years due to limited model robustness. This work proposes LiT-G2P, a novel framework that uniquely integrates linear models—capturing additive genetic effects—with a Transformer architecture to model nonlinear SNP–SNP interactions. Leveraging genome-wide SNP data, attention mechanisms, and genotype-stratified analysis, LiT-G2P achieves single-year and cross-year root mean square errors (RMSE) of 0.469 and 0.454, respectively, corresponding to prediction accuracies of 79.2% and 74.6%, outperforming existing baselines. Moreover, the model’s attention weights enable identification of biologically interpretable candidate functional SNP markers, enhancing both predictive performance and genomic interpretability in perennial crop breeding.