GENOTYPIC VARIATION AND ALTERNATING DNA LEVELS AT CONSTANT CHROMOSOME NUMBERS IN THE LIFE HISTORY OF THE BROWN ALGA HAPLOSPORA GLOBOSA (TILOPTERIDALES) 1
ABSTRACT The brown algal order Tilopteridales contains three monospecific genera with reduced life histories, Which are assumed to have been derived form ancestors with oogamous reproduction and alternation of generations. The Newfoundland population of Haplospora globosa Kjellman still shows an alt...
| Published in: | Journal of Phycology |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1993
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/j.0022-3646.1993.00377.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-3646.1993.00377.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-3646.1993.00377.x |
| Summary: | ABSTRACT The brown algal order Tilopteridales contains three monospecific genera with reduced life histories, Which are assumed to have been derived form ancestors with oogamous reproduction and alternation of generations. The Newfoundland population of Haplospora globosa Kjellman still shows an alternation of gametophytes and sporophytes, but the chromosome Numbers remain equal because of parthenogenesis and apomeiosis, However, DNA fluorometry showed that the DNA level is twice as high in the Sporophytes as in the gametophytes, The DNA variation at constant chromosome numbers is presumably due to endomitosis combined with a law degree of polyteny. A genotypic variant of Haplospora is represented by the population at Helgoland (F.R.G.) where only sporophytes exist, Spores develop into sporophytes instead of gametophytes, and the plants have reduced chromosome number but the same DNA level as the Newfoundland sporophytes |
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