Karyomorphological analysis of four species of Zingiberaceae from Thailand

Abstract

Somatic chromosome numbers and karyomorphological details of for four species of Thai Zingiberaceae belonging to the genera Alpinia, Elettariopsis and Kaempferia were determined using tissue samples from root tips. The chromosome numbers of both Alpinia siamensis and Elettariopsis biphylla were 2n = 48, for Kaempferia marginata it was 2n = 42, and that of Kaempferia rotunda was 2n = 30. We observed asymmetrical karyotypes, including metacentric (m), submetacentric (sm) and telocentric (t) chromosomes in some species. The karyotype formulae were as follows: A. siamensis 2n = 48 = 42m + 6sm; E. biphylla 2n = 48 = 18m + 26sm + 4t; K. marginata 2n = 42 = 28m + 14sm and K. rotunda 2n = 30 = 14m + 16sm. Telocentric chromosomes were observed in the 21st and 22nd chromosome pairs in E. biphylla. The karyotypes of K. rotunda and K. marginata detailed here are the first report. The chromosome analysis shows that these species differ in the chromosome number and the total chromosome length, albeit had similar chromosome morphology and asymmetry indexes.