Chromosome Elimination and Phenotypic Variability in a Trispecific Nicotiana Hybrid

Abstract

The F₁ plants of the three species cross (Nicotiana glutinosa×N. trigonophylla) ×N. megalosiphon exhibited a high amount of interplant morphological variation.
Cytological examination of some of the hybrids showed that 1 to 11 chromosomes were eliminated in different plants. One to three bivalents per PMC were observed in most of the plants. Spore formation was irregular resulting in low pollen fertility and the hybrids were completely sterile.
It is assumed that the elimination of chromosomes was random, taking place in the early stages of embryo development and that the loss of different chromosomes was responsible for the variability observed in the trispecific progeny.