Karyotypic Analysis of Two Diploid Species of <i>Crotalaria</i> (Fabaceae, Papilionoideae) with Different Degrees of Floral and Foliar Specialization

An enzymatic maceration and Giemsa staining method was used to compare the karyotypes of Crotalaria laburnifolia (trifoliate) C. spectabilis (simple leaves) species belonging distinct morphological sections with different degrees floral specialization. Both taxa share a 2n=16, asymmetric chromosome complement, relatively similar karyotypic formulae. However, differences in chromosome-SAT, sizes, other related parameters stand out. Although secondary constrictions (SC) associated satellites are located on short arms metacentric chromosomes, their position size different. In laburnifolia, were detected second chromosomal pair not first, as is usual Crotalaria, representing less than half arm length. contrast, spectabilis, first occupies most arm. The role SCs nucleolus organizing regions (NORs) corroborated prometaphase cells, they frequently observed adjacent or even embedded single large nucleolus. Furthermore, possible relationship between specialization leaf morphology discussed concerning sizes obtained. It confirmed that characterization favorable diversity provides valuable information organization evolution its karyotypes.