Chromosome studies in Andean taxa of Alstroemeria (Alstroemeriaceae)

Abstract

Meiotic or mitotic chromosomes of seven Alstroemeria taxa, native in Argentina and Chile and with Andean distribution were studied: A. andina ssp. uenustula, A. hookeri ssp. cummingiana, A. hookeri ssp. recumbens, A. pallida, A. patagonica, A. pseudospathulata and A. pygmaea. AlI were diploid with 2n = 16. Karyotypes of A. andina ssp.venustula and A. pygmaea were analysed, revealing similarity to previously analysed species. Thus, to all existing arguments for not retaining Schickendantzia as a separate genus, we can add another one which merges A. pygmaea with other Alstroemeria species, and does not support its taxonomic uniqueness. In general, the meiotic behaviour was normal, with regular formation of eight bivalents except in A. hookeri ssp. cummingiana, in one plant of which meiotic irregularities at various stages were observed. At the tetrad stage a large percentage of the cells presented micronuclei. The presence of 0-2 supernumerary chromosomes in A. hookeri ssp. recumbens is recorded. The karyotype asymmetry presented by most Alstroemeria species is discussed.