Articles
INTERSPECIFIC HYBRIDS IN LILY: VERIFICATION USING MOLECULAR MARKERS
Article number
900_30
Pages
243 – 250
Language
English
Abstract
In breeding programs of ornamental crops, interspecific hybridization is one of the most important ways to introduce new genetic variation.
The genus Lilium generally includes allogamous species with problems of self-incompatibility and the consequent inability to produce viable seeds when they are self-pollinated.
The intraspecific crosses produce a large quantity of seeds, whereas interspecific crosses create many problems.
A breeding program on Lilium was carried out at CRA-VIV with the aim to overcome barriers of interspecific incompatibility and to originate hybrids presenting new ornamental traits from various species.
Several crosses among Oriental hybrid (Lombardia) and L. longiflorum hybrid (White Heaven) were made by using the cut-style method.
Ovary and ovule culture have been applied to overcome post-zygotic barriers.
To confirm the hybrid origin of new bulblets obtained, two molecular methods have been tested: SCAR and PCR-RFLP markers.
For the first marker construction, a 700 bp band, that can differentiate male and female parental genotypes, have been selected from RAPD experiments, cloned and sequenced.
From the sequence three couples of primers have been depicted (software Primer3) and tested in all possible combinations.
The couple of P1-P6 primers gave the best result because it amplified male parental, White Heaven, and hybrid genotypes but not the female one.
For PCR-RFLP, genomic DNA of the Oriental hybrid Lombardia and L. longiflorum White Heaven have been amplified with primers SH013 and SH015 that amplified ITS1 region.
These amplicons have been sequenced and the resulting sequences have been used to construct maps of restriction enzyme sites using a restriction enzyme finder software.
These maps allow the choice of some restriction enzymes that cut differentially the two parental ITS1 amplicons.
However, when used to digest nrDNA amplicons of both parental and the hybrids, these enzymes did not give reliable results.
The genus Lilium generally includes allogamous species with problems of self-incompatibility and the consequent inability to produce viable seeds when they are self-pollinated.
The intraspecific crosses produce a large quantity of seeds, whereas interspecific crosses create many problems.
A breeding program on Lilium was carried out at CRA-VIV with the aim to overcome barriers of interspecific incompatibility and to originate hybrids presenting new ornamental traits from various species.
Several crosses among Oriental hybrid (Lombardia) and L. longiflorum hybrid (White Heaven) were made by using the cut-style method.
Ovary and ovule culture have been applied to overcome post-zygotic barriers.
To confirm the hybrid origin of new bulblets obtained, two molecular methods have been tested: SCAR and PCR-RFLP markers.
For the first marker construction, a 700 bp band, that can differentiate male and female parental genotypes, have been selected from RAPD experiments, cloned and sequenced.
From the sequence three couples of primers have been depicted (software Primer3) and tested in all possible combinations.
The couple of P1-P6 primers gave the best result because it amplified male parental, White Heaven, and hybrid genotypes but not the female one.
For PCR-RFLP, genomic DNA of the Oriental hybrid Lombardia and L. longiflorum White Heaven have been amplified with primers SH013 and SH015 that amplified ITS1 region.
These amplicons have been sequenced and the resulting sequences have been used to construct maps of restriction enzyme sites using a restriction enzyme finder software.
These maps allow the choice of some restriction enzymes that cut differentially the two parental ITS1 amplicons.
However, when used to digest nrDNA amplicons of both parental and the hybrids, these enzymes did not give reliable results.
Publication
Authors
B. Nesi, A. Haegi, J. Mori, S. Lazzereschi, S. Pecchioli, A. Grassotti
Keywords
ornamental bulbs, sexual barriers, SCAR marker, PCR-RFLP analysis
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