Comparative and Phylogenetic Analysis of Complete Chloroplast Genomes of Five Mangifera Species

<b>Background/Objectives</b>: Mango, which is known as the "King of Tropical Fruits", is an evergreen plant belonging to the Anacardiaceae family. It belongs to the genus <i>Mangifera</i>, which comprises 69 species of plants found in tropical and subtropical regions, including India, Indonesia, the Malay Peninsula, Thailand, and South China. However, research on the structural information of complete chloroplast genomes of <i>Mangifera</i> is limited. <b>Methods</b>: The rapid advancement of high-throughput sequencing technology enables the acquisition of the entire chloroplast (cp) genome sequence, providing a molecular foundation for phylogenetic research. This work sequenced the chloroplast genomes of six <i>Mangifera</i> samples, performed a comparative analysis of the cp genomes, and investigated the evolutionary relationships within the <i>Mangifera</i> genus. <b>Results</b>: All six <i>Mangifera</i> samples showed a single circular molecule with a quadripartite structure, ranging from 157,604 bp to 158,889 bp in length. The number of RNA editing sites ranged from 60 to 61, with ndhB exhibiting the highest number of RNA editing sites across all species. Seven genes-namely, <i>atpB</i>, <i>cemA</i>, <i>clpP</i>, <i>ndhD</i>, <i>petB</i>, <i>petD</i>, and <i>ycf15</i>-exhibited a Ka/Ks value > 1, suggesting they may be under positive selection. Phylogenetic analysis revealed that <i>Mangifera siamensis</i> showed a close relationship between <i>Mangifera indica</i> and <i>Mangifera sylvatica</i>. <b>Conclusions</b>: Our comprehensive analysis of the whole cp genomes of the five <i>Mangifera</i> species offers significant insights regarding their phylogenetic reconstruction. Moreover, it elucidates the evolutionary processes of the cp genome within the <i>Mangifera</i> genus.