ABSTRACT: Despite Macadamia's global economic importance as a nutrient-dense nut crop, the structural and evolutionary characteristics of its chloroplast genomes (plastomes) remain underexplored. Here, we present the first comprehensive plastomic analysis of 185 cultivated Macadamia accessions from a Chinese germplasm collection. These plastomes exhibited conserved quadripartite structures (159,195-159,726 bp), comprising a large single-copy (LSC, 87,651-88,107 bp), a small single-copy (SSC, 18,743-18,819 bp), and inverted repeats (IRs, 26,378-26,422 bp). All plastomes maintained 115 functional genes (81 protein-coding, 30 tRNA, 4 rRNA) and were classified into 23 unique haplotypes. We identified 573 SNPs, 577 long repeats, and five hypervariable regions (trnS-trnG-exon1, ndhD-psaC, trnH-psbA, petA-
