Genetic diversity and relationship of mango and its wild relatives (Mangifera spp.) based on morphological and molecular markers

Abstract

Mango and its wild relatives (Mangifera spp.) are essential for future mango breeding, including preservation programs, because they provide many beneficial genes (agronomic traits), particularly those related to resistance to biotic and abiotic stressors. However, there is a limited understanding of the genetic diversity and relationships of this germplasm. This study aimed to determine the diversity and relationship between endemic mango and its wild relatives (Mangifera spp.) from Borneo Island, Indonesia, using leaf morphology and the internal transcribed spacer (ITS) region. Fifteen samples of Mangifera, covering 12 species, were used. Morphologically, the endemic Mangifera had a low diversity of only 0.22. Based on the ITS sequence, Mangifera endemic to Borneo had a high level of genetic diversity (0.069). In addition, this sequence had a total variable number of 215 bp, of which 110 bp were singleton sites, 89 informative parsimony and 41 indels. Phylogenetic analysis showed that Mangifera was grouped into three clusters for leaf morphological traits and four clades for the ITS region. In this case, the furthest relationship was pointed out by ‘Hampalam’ (M. laurina) and ‘Tambusui’ (M. macrocarpa), as well as by ‘Rawa-Rawa’ (M. similis) and ‘Samputar’ (M. torquenda). In contrast, the closest relationship was shown by ‘Hambawang Damar’ (M. foetida) and ‘Hambawang Puntara’ (M. foetida), including ‘Samputar’ (M. torquenda) and ‘Pauh’ (M. quadrifida). In particular, the common mango (M. indica) was closely related to ‘Asam Buluh’ and ‘Hampalam’ (M. laurina) and distantly related to ‘Pauh’ (M. quadrifida) and ‘Rawa-Rawa’ (M. similis).