ISHS Acta Horticulturae 508: XIX International Symposium on Improvement of Ornamental Plants
MOLECULAR CYTOGENETIC ANALYSIS OF GENOME ORGANISATION IN ALSTROEMERIA |
| Authors: | A.G.J. Kuipers, S.A. Kamstra, M.J. De Jeu, M.S. Ramanna |
| Abstract:
Alstroemeria is a rhizomatous perennial ornamental species cultivated in greenhouses for cut flower production. Alstroemeria is endemic to South-America, mainly Chile and Brazil. For cultivar development interspecific hybrids are produced between Chilean and Brazilian species by using embryo rescue techniques. In order to define the genome organisation in the interspecific hybrids the following study was carried out using genomic in situ hybridisation (GISH) and fluorescent in situ hybridisation (FISH) with satellite DNA sequences as probe (De Jeu et al., 1995, De Jeu et al., 1997, Kuipers et al., 1997). Four Chilean species: A. aurea and A. ligtu (both with pronounced heterochromatic regions according to the Giemsa C-bands), A. pelegrina and A. magnifica (with minor C-bands) and two Brazilian species: A. inodora and A. psittacina (both with minor C-bands) were studied with GISH and FISH. A. aurea and A. ligtu genomes contained highly repetitive species-specific DNA sequences that, after localisation with FISH, were found to coincide with the Giemsa C-banding patterns. The repetitive DNA sequences isolated from the Brazilian species A. inodora and A. psittacina contained several homologous repeats. Using these repeats in FISH of A. inodora and A. psittacina chromosomes resulted in the same localisation patterns as found in A. aurea and A. ligtu, despite the fact that in the Brazilian species no or minor Giemsa-C banding patterns were present. It seems that the molecular organisation of the genomes of Alstroemeria with the presence of highly repetitive DNA sequences is similar in the two Chilean and two Brazilian species whereas other factors may influence the occurrence of heterochromatic regions. In conclusion both GISH and FISH are applicable in Alstroemeria hybrids for the identification of the parental genomes. The highly repetitive species-specific DNA sequences are localised in specific regions of the chromosomes; in A. aurea these regions coincided with heterochromatic regions. The repetitive DNA sequences isolated from A. inodora and A. psittacina contained homologous sequences indicating that they are closely related to each other. | |
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