Whole Genome Re-Sequencing Reveals Insights into the Genetic Diversity and Fruit Flesh Color of Guava

Guava (Psidium guajava L.), a perennial species native to tropical regions of the Americas, holds significant economic value and plays an important role in the global fruit industry. Although several reference genomes have been published, population-level genomic studies remain limited, hindering genetic improvement efforts. In this study, we conducted whole genome re-sequencing of 62 guava accessions, primarily from Southern China and Brazil. A total of 4,887,006 high-quality SNPs and 731,469 InDels were identified for population genomic analyses. Phylogenetic and population structure analyses revealed subgroupings that largely corresponded to geographic origins. The data indicated that extensive hybridization between accessions from Brazil and or within China has contributed to the development of many dominant commercial varieties. Genetic diversity analyses showed that Brazilian accessions exhibited higher nucleotide diversity and more rapid linkage disequilibrium decay than those from China. Environmental factors and artificial selection likely imposed selective pressures that shaped guava’s adaptability and agronomic traits. A preliminary genome-wide association study (GWAS) identified PgMYB4 as a candidate gene potentially associated with fruit flesh color. These findings provide novel insights into the genetic diversity, population history, and domestication of guava, and lay a valuable foundation for future breeding and improvement strategies.