Single-seed LIBS spectra of isogenic diploid and tetraploid Arabidopsis thaliana seed stocks (CS69111, CS69112)

Raw single-shot laser-induced breakdown spectroscopy (LIBS) spectra of 153 whole seeds of the isogenic Landsberg erecta stocks CS69111 (diploid) and CS69112 (autotetraploid), acquired on 3–4 September 2026 with the two stocks alternated seed by seed. One tab-separated file per seed, 4,096 channels over 192.60–1104.93 nm. Includes the analysis code (preprocessing, PLS-DA classification, grouped, block-wise and session-wise validation, controls, line attribution and figures) and a script that reproduces the statistics added in revision. Data and code for the manuscript "Single-seed laser-induced breakdown spectroscopy discriminates isogenic diploid and tetraploid Arabidopsis thaliana seed stocks: acquisition design, controls and a seed-coat sodium signal", submitted to BMC Agriculture.