The Chromosomes of Species, Hybrids and Cultivars of Narcissus L. (Amaryllidaceae)

Abstract

Chromosome counts are reported for 46 taxa, 8 F, hybrids and 230 cultivated varieties of Narcissus L. and the percentage pollen viability is given for most of them. B chromosomes were found in several species and cultivars. Chromosome numbers rise to the hexaploid level (2n = 42, 43) in species of the subgenus Narcissus, but the diploid (2n = 14) is the most commonly-occurring level of ploidy. In the subgenus Hermione diploid chromosome counts of 2n = 20 and 22 were obtained (x = 10, 11), in confirmation of reports by previous workers. In cultivars solely derived from the subgenus Narcissus euand aneu-tetraploids (2n = 28 + 2) greatly exceed diploids in frequency. Cultivars with complex ancestry involving x = 7 and x = 10 or 11 plants display a wide range of chromosome numbers, and the probable derivation of the chromosome complements of these cultivars and of other real and apparent aneuploids, together with those of some of the more interesting euploids, are given in the light of current knowledge. The levels of ploidy extant in Narcissus cultivars are compared and contrasted with those of a range of other genera in which many ornamental cultivars have also been produced.