Karyotype analysis of Astragalus effusus Bunge (Fabaceae)

Abstract In this study, the karyotype analysis of Astragalus effusus Bunge species was studied using Image Analysis System. The protocol assayed consisted of the use of α-bromonaphthalene for pretreatment, Lewitsky solution for fixation, 1N NaOH for hydrolysis and finally, aceto iron-hematoxylin for staining stage. The species’ chromosome number was 2n = 4× = 32, chromosome lengths range from 1.57 to 2.99 μm and the length of the whole genome was 75.8 μm; also, the chromosome length and arm lengths showed this species was most likely natural autotetraploid and observed one pericentric inversion in chromosomes of the VIII group. Regarding the karyotypic symmetry, this species belongs to the 2A karyotypic symmetry class with a 7m + 2msat + 7sm karyotype formula. Asymmetrical parameters emphasize on rather symmetry karyotype in this species. In this paper, we assess the karyotype of this species for the first time.