The mitogenomes of Phytophthora meadii and P. palmivora: organization, evolution and phylogeny

Phytophthora meadii and P. palmivora are highly destructive plant pathogens, causing fruit and crown rot in arecanut and bud rot in coconut, respectively. In this study, we assembled and characterized the mitochondrial genomes of P. palmivora and P. meadii, analyzing their gene composition and structural organization. Additionally, we performed comparative analyses of mitochondrial genomes and investigated phylogenetic relationships among oomycete species. The complete mitochondrial genomes of P. palmivora (38,708 bp) and P. meadii (37,974 bp) were assembled, with coding regions accounting for approximately 74% and 72% of the total genome in P. palmivora and P. meadii, respectively, with G + C contents of 21.88% and 21.45%. Intergenic regions comprised approximately 11.3% of the P. palmivora mitogenome and 10.2% of the P. meadii mitogenome. While P. palmivora was predicted to encode 39 protein-coding genes (PCGs), P. meadii contained 37 PCGs. Both mitogenomes included two ribosomal RNA genes (rns and rnl) and 25 transfer RNA (tRNA) genes. Nucleotide composition analysis revealed a bias toward A/T over G/C. Phylogenomic analysis based on 34 protein-coding genes placed P. palmivora and P. meadii within the same clade, further supporting their close evolutionary relationship.