Genetic diversity and phylogenetic relationships of a potential cotton collection for European breeding research

An understanding of the genetic diversity of any plant collection is essential for initiating future plant breeding strategies. Throughout the cotton regions in Europe (mainly Greece and Spain), there is an expanding need for new yielding varieties with shorter crop cycles and high quality fiber. Although cotton is decisive to many rural economies, it is surprising that there is a lack of public information available regarding genetic diversity of European cotton varieties. Thus, we began an examination of variability heritage by evaluating a subset of 48 commercial and experimental cotton varieties (36 Gossypium hirsutum, 10 G. barbadense, 1 G. arboreum, and 1 unknown species) using 67 microsatellite markers (SSRs). Sixty-two SSRs (92.54%) showed polymorphism and revealed 464 alleles. The total polymorphism information content value was 0.7 (0.57 in G. hirsutum and 0.54 in G. barbadense), which indicates a high informative content of our SSR set compared to that obtained in previous cotton studies and plant collections. Cluster analysis was performed to analyze diversity results and phylogenetic relationships between and within species. These results established a foundation for the future development of improved commercial cotton varieties and can thereby help the European cotton industry meet pressing needs.