In this work the in vitro culture response of six population samples of Brachypodium distachyon (two by each one of the cytotypes of 2n = 10 2n = 20; 2n = 30) has been analyzed. Immature zygotic embryos distachwere seeded for callus induction in nine culture media (BR1 to BR9), that were different to each other in the growth regulator kind of (2, 4-dichlorophenoxyacetic acid (2, 4-D), Picloran or Dicamba) and concentration (1, 2 or 4 mg/l), with four repetitions with 20 embryos per treatment. Results were subsequently analyzed using an ANOVA test for the following variables:TC = total calluses number / total embryos number; CC = compact calluses number / total calluses number; SC = soft calluses number/ total calluses number. A very different response among them, as much for the number as for the type of callus developed, has been observed, based on the genotype and culture medium used. Thus, the samples with 2n = 30 chromosomes gave rise to a greater number of total calluses and embryogenic calluses. The culture mediums that induced the best response were those that contained 2, 4-D in all the concentrations tested. The obtained calluses were distributed in four repetitions and they were seeded in the regeneration media containing N6-benzyl-aminopurine BAP (0.5 mg/l) and were transferred to a chamber growth with a photoperiod of 14 h light and a constant temperature of 22ºC. After a month, the number of developed buds (green or albinos) was counted and were estimated the following variables: TSV = total number of buds (green + albinos) / total number of calluses; TSVC = number of green buds / total number of calluses; SCC = number of green buds from compact calluses / total number of compact calluses; SSC = number of green buds from soft calluses /total number of soft calluses; Total green buds/total immature embryos (R). The ANOVA test for each one of the variables revealed significant differences between the populations. The study of the variable R, that summarizes the response of the in vitro culture, has allowed classifying the six populations based on its aptitude for the regeneration of plants from the in vitro culture of immature embryos. Thus, two populations of 2n = 30 chromosomes, Bd238 and Bd341 were those of the best behavior, whereas the populations Bd160 and `Zulema’ with 2n = 10 chromosomes, showed the lowest response