Genetic diversity of Zingiber officinale (Zingiberaceae) germplasm grown in urban and rural backyards in Mato Grosso, Brazil
Ginger (Zingiber officinale Roscoe) is a self-incompatible plant and has high rates of infertility; its genetic diversity only occurs via processes of mutation and natural selection. Since ginger is important as a condiment and as an herbal medicine, understanding its diversity to a greater degree can contribute both to its conservation and to its use in breeding programs. Considering the importance of the species and the characterization of material from on-farm conservation, this study aimed to evaluate, by means of ISSRs (Inter Simple Sequence Repeats) molecular markers of genetic diversity among individuals obtained in 19 urban and rural backyards in Alta Floresta, Mato Grosso state, Brazil. For the extraction of total DNA, the CTAB method was used and the amplifications were performed using nine ISSR primers. The UPGMA clustering method, when compared with the Ward and Nearest Neighbor methods, best showed genetic diversity, and the Bayesian analysis defined two distinct groups in the Z. officinale germplasm that was evaluated. The ISSR primers amplified a total of 78 fragments and revealed 88% polymorphism. The PIC varied between 0.40 and 0.87, with an average of 0.70, and was classified as median in the detection of polymorphism. The most dissimilar individuals were AF06 and AF12, while the least dissimilar were AF06 and AF04. The Nei (He) and Shannon (I) diversity indices demonstrated genetic variability within the two groups formed from the Bayesian analysis, and AMOVA indicated that the genetic diversity was greater within the groups (53.06%) than among them (46.94%). The absence of duplicates among the individuals analyzed indicates that they can be used to form an active germplasm collection with the aim of conserving and maintaining the genetic diversity of the species.