Articles
COMPARISON OF HOMOEOLOGOUS RECOMBINATION FREQUENCY BETWEEN MITOTIC AND MEIOTIC POLYPLOIDIZATION IN BC1 PROGENY OF INTERSPECIFIC LILY HYBRIDS
Article number
552_6
Pages
65 – 72
Language
English
Abstract
Wide interspecific hybrids of lily generally show F1-sterility.
For overcoming this crossing barrier mitotic polyploidization (artificial chromosome doubling) or meiotic polyploidization through unreduced gametes can be applied.
For introgression of the desirable characters from a donor into the recipient, homoeologous recombination is essential. 2x-gametes and 2n-gametes were compared with respect to the frequency of homoeologous recombination between parental chromosomes, in the F1-hybrids as well as in BC1 progenies.
GISH (genomic in situ hybridization) revealed that the LR and LA hybrids (2n=2x=24) composted of each genome set of parental chromosomes.
These two types of F1-hybrids (LR and LA) were used as a male parent to L. longiflorum and Asiatic hybrids.
Since the LR-hybrid was absolute sterile, the chromosome number of this hybrid was doubled artificially, which recovered its fertility.
GISH results revealed that the BC1 individuals (2n=3x=36), LLR and ALA, differed on homoeologous recombination frequency.
Recombinant chromosomes were not be demonstrated in the mitotic chromosome complements of the LLR-hybrids.
This lack of exchange between homoeologous chromosomes caused by complete preferential pairing of the L-L and R-R chromosomes during the meiosis of F1-hybrid (LLRR). On the contrary, ALA-hybrids derived from functioning of 2n-gamete of LA hybrids showed a range of homoeologous recombinations between L and A chromosomes.
Homoeologous recombinations were obtained by homoeologous pairing between L and A chromosomes during meiosis.
As a conclusion, 2n-gametes producing F1 interspecific hybrids have a high potential to introgress certain characteristics selectively.
For overcoming this crossing barrier mitotic polyploidization (artificial chromosome doubling) or meiotic polyploidization through unreduced gametes can be applied.
For introgression of the desirable characters from a donor into the recipient, homoeologous recombination is essential. 2x-gametes and 2n-gametes were compared with respect to the frequency of homoeologous recombination between parental chromosomes, in the F1-hybrids as well as in BC1 progenies.
GISH (genomic in situ hybridization) revealed that the LR and LA hybrids (2n=2x=24) composted of each genome set of parental chromosomes.
These two types of F1-hybrids (LR and LA) were used as a male parent to L. longiflorum and Asiatic hybrids.
Since the LR-hybrid was absolute sterile, the chromosome number of this hybrid was doubled artificially, which recovered its fertility.
GISH results revealed that the BC1 individuals (2n=3x=36), LLR and ALA, differed on homoeologous recombination frequency.
Recombinant chromosomes were not be demonstrated in the mitotic chromosome complements of the LLR-hybrids.
This lack of exchange between homoeologous chromosomes caused by complete preferential pairing of the L-L and R-R chromosomes during the meiosis of F1-hybrid (LLRR). On the contrary, ALA-hybrids derived from functioning of 2n-gamete of LA hybrids showed a range of homoeologous recombinations between L and A chromosomes.
Homoeologous recombinations were obtained by homoeologous pairing between L and A chromosomes during meiosis.
As a conclusion, 2n-gametes producing F1 interspecific hybrids have a high potential to introgress certain characteristics selectively.
Publication
Authors
K.B. Lim, M.S. Ramanna, J.M. van Tuyl
Keywords
unreduced gametes, homoeologous recombination, Lilium rubellum, L. longiflorum, genomic in situ hybridization (GISH)
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