Comparative karyotype analysis in populations of Alstroemeria ligtu subsp. ligtu and A. ligtu subsp. simsii (Alstroemeriaceae) from Chile

Abstract

Alstroemeria (Alstroemeriaceae) is a genus endemic to South America. In Chile, this genus is distributed from the northern end to Patagonia, with a diversification center in central Chile. Precisely in this central zone grows Alstroemeria ligtu with its three subspecies: A. ligtu subsp. incarnata, A. ligtu subsp.  simsii and A. ligtu subsp.  ligtu. A comparative study of the karyotype with DAPI or acetic orcein of 5 populations of A. ligtu subsp. ligtu from the VIII Region, and one population of A. ligtu subsp. simsii from the V Region was made. The karyotype observed in these six studied populations was asymmetric, with 2n=2x=16 chromosomes. The populations of A. ligtu subsp.  ligtu presented a haploid formula conformed by four metacentric chromosomes (pairs 1 and 2 with microsatellites), one submetacentric chromosome with a microsatellite, and three telocentric chromosomes with microsatellites. The haploid formula of A. ligtu subsp. simsii was: five metacentric chromosomes (pair 2 with a microsatellite, and pair 6 with a secondary constriction) and three telocentric chromosomes with satellite. Therefore, the karyotype of A. ligtu is variable, and changes at chromosomal level have probably contributed to the diversification of this species.