Genome constitution of Narcissus variety, 'Tete-a-Tete', analysed through GISH and NBS profiling

Résumé

The Narcissus variety, ‘Tête-à-Tête’, has been the most popular variety since 1949, and a well known allotriploid (2n = 3x = 24 + B) of spontaneous origin. Because the identity of one of the parents of this variety was uncertain, the genome constitution of ‘Tête-à-Tête’ was investigated by using genomic in situ hybridization (GISH) and NBS profiling. Both of these techniques confirmed that two different species of Narcissus, viz., N. tazetta (2n = 2x = 20) and N. cyclamineus (2n = 2x = 14) are the parents. GISH clearly identified 10 chromosomes of N. tazetta and 14 chromosomes of N. cyclamineus, the former has contributed one and the latter has contributed two genomes. One B chromosome was identically labelled as those of N. cyclamineus indicating the affinity of the special chromosome to this species. Due to its male and female sterility ‘Tête-à-Tête’ is unsuitable as a parent for utilizing in further breeding, it might be possible to re-synthesize a ‘Tête-à-Tête’ like variety using the now known parents and the original pathway