Chromosomal Changes in Prosopis glandulosa var. torreyana (Honey Mesquite) Species Widely Distributed in North America

A cytogenetic study using conventional surface-spread, air-dried, Giemsa-stained techniques were performed in somatic cells from six individuals of Prosopis glandulosa var. torreyana belonging to a population in northern Mexico. The results confirmed chromosome number 2n= 28 and its karyotype generally consistent with that shown in other species of mimosoid whose karyotypes are characterized by a predominance of chromosomes with a medium or slightly displaced centromere and few subterminal centromeres. However, there were differences in chromosomal morphology concerning other Prosopis species involving chromosome size and the location, shape, and size of the satellites on the SAT chromosomes. The evidence of chromosomal remodeling, not previously described in this genus, favors its possible participation as a genetic isolation mechanism that would prevent the formation of viable hybrids, as has been recorded in other studies.