Cytogenetics of tropical bulbous ornamentals VI: Chromosomal polymorphism in cultivated zephyranthes

Abstract

Nineteen different chromosome numbers ranging from 2n = 18 to 96 have been obtained from an analysis of 8 species and 65 garden cultivars of the genus Zephyranthes. Since the related genus Habranthus, with which Zephyranthes freely hybridises, has 2n = 12 it is concluded that the basic number of the genus is 6. The numerical range within the genus thus extends from 3x to 16x and superimposed upon this polyploid series is a secondary aneuploidy. This poly-aneuploid system is confounded by a large degree of heteromorphism in chromosome morphology. A small part of this heteromorphism stems from the presence of a stable telocentric in three cultivars but the main cause for this lack of regular homology remains to be defined. © 1971 Taylor & Francis Group, LLC.