ORIGIN OF APOMICTIC RED ALGAE : OUTCROSSING STUDIES OF DIFFERENT STRAINS IN CALOGLOSSA MONOSTICHA (CERAMIALES, RHODOPHYTA)(1)
© 2008 Phycological Society of America.
| Publié dans: | Journal of phycology. - 1966. - 44(2008), 4 vom: 15. Aug., Seite 977-84 |
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| Auteur principal: | |
| Autres auteurs: | |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2008
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| Accès à la collection: | Journal of phycology |
| Sujets: | Journal Article apomeiosis apomixis asexual reproduction hybridization mixed-phase reproduction tetraspore recycling |
| Résumé: | © 2008 Phycological Society of America. Various red algae lack sexual reproduction and propagate by spore recycling, but it is still unknown how apomixis originates. In previous crossing experiments, we obtained an unusual hybrid of Caloglossa monosticha M. Kamiya through the outcrossing between a male from Australia and a female from Indonesia. This hybrid was morphologically identical to a normal tetrasporophyte, but its tetraspores grew into tetrasporophytes and repeated tetraspore recycling. During 5 years of culture, no sexual reproductive structures have formed on the tetrasporelings from this hybrid or its progenies. Further hybridization experiments revealed that all the five female strains from Indonesia successfully crossed with the male strain from the East Alligator River, Australia, and most of the F1 sporophytes demonstrated tetraspore recycling, though the germination rates of these tetraspores were quite low. The ploidy level of the hybrid tetrasporophyte was similar to the normal tetrasporophyte, rather than the parental gametophyte, based on the comparison of relative DNA contents of their nuclei. Single strand conformation polymorphism (SSCP) and sequence analyses of the internal transcribed spacer 1 (ITS1) region indicated that the alleles from both parents were present in all the hybrid tetrasporophytes examined. These results suggest that this hybrid does not carry out meiosis during sporogenesis, and heterozygous diploid sporophytes arose from tetraspores. Therefore, we believe that obligate apomixis was generated through outcrossing between genetically different entities of C. monosticha |
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| Description: | Date Completed 05.04.2016 Date Revised 09.01.2024 published: Print GENBANK: AB365320, AB365346 Citation Status PubMed-not-MEDLINE |
| ISSN: | 1529-8817 |
| DOI: | 10.1111/j.1529-8817.2008.00551.x |