HYPER-SEQ SNP GENOTYPING REVEALS CRITICALLY LOW GENETIC DIVERSITY IN THE ENDANGERED TREE MADHUCA PASQUIERI (SAPOTACEAE)

Wild populations of Madhuсa pasquieri, a nationally protected tree, have become highly fragmented in Guangxi, China.To establish a genomic baseline for conservation, we genotyped 35 individuals from four populations using Hyper-seq genotyping.Hyper-seq genotyping is a low-cost, highthroughput approach that constructs barcoded, reduced-representation libraries in a single PCR, enabling flexible marker density without restriction digestion.Across populations, mean observed heterozygosity (HO = 0.4318), expected heterozygosity (HE = 0.2548) and nucleotide diversity (π = 0.4423) fall within the range documented for fragmented subtropical tree species.Tajima's D was positive in three populations, consistent with recent contraction and small effective size.Population-pair FST averaged 0.062, pointing to moderate genetic differentiation that was unrelated to geographic distance.ADMIXTURE and PCA resolved two genetic clusters; TXLJZ and JXCDX showed comparatively higher within-population diversity.These genomic baselines reveal a species already experiencing heterozygote surplus and signals of demographic contraction.These results provide a genomic baseline and actionable guidance for monitoring and conservation planning in Madhuсa pasquieri.