High-throughput phenomic survey of seed morphological diversity in common and tartary buckwheat germplasm

Buckwheat (Fagopyrum spp.) germplasm represents an underutilized source of morphological diversity for crop improvement. This study presents a high-throughput phenomic survey quantifying five seed morphological traits (area, length, width, circularity, roundness) across 563 RDA genebank accessions (519 common buckwheat (F. esculentum), 44 Tartary buckwheat (F. tataricum) using standardized imaging. Common buckwheat exhibits larger seeds (area: 21.12 ± 4.04 mm²) with lower coefficients of variation (CVs: 17.9%), while Tartary buckwheat shows smaller seeds (14.80 ± 3.23 mm²) with higher CVs (20.1%) and greater shape dispersion (PC2 variance: 3.73 vs. 1.06). Principal component analysis confirms species-level morphological separation and documents exploitable polymorphism, including notched/slender/round/rice morphotypes in F. tataricum. These standardized phenotypic baselines support genebank curation, accession ranking by seed size/shape extremes, and prioritization for multi-environment trials and genetic studies.