To study the genetic diversity of Guadua angustifolia Kunth, the world's third largest bamboo species, 55 accessions were evaluated using microsatellite sequences of rice and sugarcane, crops genetically related to this species. Amplifications were obtained with 27 rice and 10 sugarcane microsatellite sequences. Six similarity groups were obtained. The first is formed mainly by individuals of G. angustifolia and biotypes from the coffee-growing region, as well as G. uncinata and G. macrospiculata. The second brings together other G. angustifolia accessions and biotypes from Antioquia, Cundinamarca, and Nariño. The third consists of G. angustifolia plants from Antioquia, Meta, and Santander and Guadua sp. 1. A fourth group is formed by G. angustifolia accessions from Santander; Antioquia, and Caldas and G superba from the Amazon. A fifth group is formed by G. amplexifolia acessions. G. angustifolia from Meta was grouped separately and presented the lowest similarity values
