Cytogenetic evidence of hybridization in Prosopis alba, P. hassleri, and P. fiebriggi in the semiarid-humid Chaco transition

VEGA C.; COSACOV A.; ACOSTA M. C.

PLANT BIOSYSTEMS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2023

1126-3504

Hybridization is a common and widespread phenomenon in vascular plants,leading to genetic exchange between related species. Interspecific hybridization hasbeen extensively reported in Prosopis, a key genus of the Gran Chaco Americano, whenspecies grow in sympatry or have adjacent distributions. Here, we performed acytogenetic study in a hybrid zone of Prosopis alba, P. hassleri, and P. fiebrigii insouthern South America. We characterized the karyotypes of pure species and theputative interspecific hybrids using chromosome fluorescent banding. Two karyotypesaccording to the heterochromatin pattern were identified, one corresponding to P. albaand the other to P. hassleri and P. fiebrigii; hybrid individuals presented P. alba or P.hassleri/P. fiebrigii karyotypes. The karyotypic formula and the number of nucleolarorganizer regions were the same for all the studied morphotypes. Chromosomesimilarity among different species of the genus allows a continued hybridization andintrogression between species and lends support to the hypothesis of a relatively recentdiversification of Prosopis. Studying karyotype variation within a population could be anovel approach to the cytogenetic study of hybrids in the future.