Phylogenetic relationships of tetraploid cotton species (Gossypium subsp.) and their genetic potential for breeding programs

Gossypium mustelinum, a rare wild cotton from Brazil, offers potential as a genetic resource for improving cultivated cottons. This study assessed its relationship with other cotton species via interspecific hybridization and genetic analysis. A total of 22 F1 hybrids were generated, exhibiting varied levels of compatibility. The var. marie-galante × G. mustelinum cross showed the highest seed set (87.2%), indicating good cross-compatibility. The F1 and F2 hybrids revealed strong potential for enhancing fiber traits. For instance, the cv. ‘Beshkahramon’ × G. mustelinum F1 hybrid had high heterosis (hp = 33.00) for fiber length. Its F2 population showed a mean fiber length of 36.2 mm (h2 = 0.62) and fiber yield of 41.2% (h2 = 0.61). SSR marker-based phylogenetic analysis confirmed a close relationship between G. mustelinum and two G. hirsutum subspecies: paniculatum (GD = 0.13) and var. marie-galante (GD = 0.17). The close relationship underscores the breeding potential of G. mustelinum.