Cytological Studies on Narcissus

I. Karyotype and nucleolinus of Narcissus jonquilla

Abstract

1. A karyological study was made on Narcissus jonquilla. The chromosome number of the twenty clones collected from five different gardens were found to be 2n=14.
2. All clones studied showed similar karyotype, i.e., the chromosomes can be grouped into seven pairs.
3. The heterochromatin located in the distal end of the short arm of the shortest pair of chromosomes shows negative heteropycnosis. It has been observed for the first time that the heterochromatin forms a nucleolinus within the nucleolus during prometaphase and resting stage.