Karyotype and Meiotic Behaviour in Zephyranthes (Amaryllidaceae) from South America

Abstract

The karyotype of five species of the genus Zephyranthes Herb. was analyzed: Z. aff. mesochloa, 2n=12; Z. aff. stellaris, 2n=20; Zephyranthes sp. (accession 1), 2n=30 and 2n=31; Zephyranthes sp. (accession 3), 2n=40 and Zephyranthes sp. (accession 4), 2n=50. The karyotype found in the five species studied is in general symmetric except for Z. aff. mesochloa. Chromosome pairing at metaphase I of three species was studied. The results showed that Zephyranthes sp. (accession 1) and Zephyranthes sp. (accession 4) are allopolyploid and that a new basic number in the genus might well be x=5. The presence of associations with more than two chromosomes in Zephyranthes sp. (accession 4) suggests that this species is a segmental allopolyploid since the genomes which participated in their origin are homoeologous. © 1989, Japan Mendel Society, International Society of Cytology. All rights reserved.