SSR-based genetic diversity of traditional and perennial cotton (Gossypium spp.) populations collected in Burkina Faso

Abstract

Cotton (Gossypium) has a long history of cultivation in Africa, witnessed by the presence of traditional cotton plants conserved in the villages. A collection of traditional cotton accessions conserved as perennial plants by farmers was made throughout Burkina Faso. The collection represents a wide range of diversity within the genus. Although the species G. hirsutum is the only cultivated species in the region, the collection of traditional cotton identified four major domesticated species based on morphological and botanical traits. It included diploid species G. arboreum and G. herbaceum, the latter represented by a single specimen, tetraploid species G. barbadense and G. hirsutum. Within G. hirsutum, annuals and perennials were distinguished. The genetic diversity and population structure of 121 accessions of the collection as assessed by SSR markers polymorphism clearly identified the 3 species, G. arboreum, G. barbadense and G. hirsutum; the G. herbaceum specimen was not distinguishable within G. arboreum group. The perennials and annuals forms within G. hirsutum were clearly separated. The persistence of those anciently cultivated cotton species and their maintenance by villagers is remarkable and fairly unique as they were introduced in the continent in the 16th century. This genetic resource could possess promising attributes related to environmental adaptation or to traditional uses and it needs to be properly characterized and preserved either in situ or ex situ.