Abstract
Interspecific hybridization between evergreen pot azalea (Tsutsusi) cultivars and genotypes of other Rhododendron subgenera or sections (Rhododendron, Hymenanthes, Pentanthera, Vireya) is significantly hampered by many prezygotic and postzygotic barriers. The objective of our work was to overcome spontaneous abortion and lack of endosperm formation and to increase germination rates by establishing an embryo rescue protocol. The optimal germination medium for immature Rhododendron seeds was a basal medium supplemented with 145 μM GA3. This medium induced germination of fertilized ovules after several sexual combinations of subgenera. Its use was clearly more efficient than in vivo sowing. The direction of the cross significantly influenced the occurrence of abortion, germination and albinism. The obtained seedlings were multiplied on Woody Plant Medium + 4.5 μM 2iP, and rooted afterwards. Finally, about 9% of the germinated ovules resulted in vigorously growing seedlings that were successfully acclimatized.
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Abbreviations
- 2iP:
-
Isopentenyladenine
- GA:
-
Gibberellic acid
- HY:
-
Subgenus Hymenanthes
- IAA:
-
Indole acetic acid
- MS:
-
Murashige & Skoog
- PE:
-
Subgenus Pentanthera
- RH:
-
Subgenus Rhododendron
- TS:
-
Subgenus Tsutsusi
- VI:
-
Section Vireya
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Acknowledgements
This work was financed by DWTC-Belgium. The authors wish to thank Romain Uytterhaegen, Ronald Van den Oord, Kristien Janssens, Veerle Cools and Laurence Desmet for technical assistance.
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Eeckhaut, T., De Keyser, E., Van Huylenbroeck, J. et al. Application of embryo rescue after interspecific crosses in the genus Rhododendron . Plant Cell Tiss Organ Cult 89, 29–35 (2007). https://doi.org/10.1007/s11240-007-9209-4
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DOI: https://doi.org/10.1007/s11240-007-9209-4