Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe)
The remarkable species diversity of the genus <i>Sorbus</i> is a result of polyploidization and frequent hybridization between interacting species of different cytotypes. Moreover, hybridization is possible between several parental taxa. Gametophytic apomixis, which is common among polyp...
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MDPI AG
2023-01-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/12/2/373 |
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| author | Vladislav Kolarčik Mária Mirková Vlastimil Mikoláš |
| author_facet | Vladislav Kolarčik Mária Mirková Vlastimil Mikoláš |
| author_sort | Vladislav Kolarčik |
| collection | DOAJ |
| description | The remarkable species diversity of the genus <i>Sorbus</i> is a result of polyploidization and frequent hybridization between interacting species of different cytotypes. Moreover, hybridization is possible between several parental taxa. Gametophytic apomixis, which is common among polyploid <i>Sorbus</i> taxa, indicates the role of clonal reproduction in the evolutionary stabilization of hybridogeneous genotypes. The precise determination of the origin of seeds and their quantitative evaluation may elucidate inter-cytotype interactions, the potential role of mixed-cytotype populations in evolutionary success, and the long-term survival of some hybrid species. We investigated the reproduction modes of selected species of <i>Sorbus</i> in mixed-cytotype populations in eastern Slovakia, Central Europe. We determined the pollen quality, seed production rate, and the ploidy level of mature trees, as well as the origin of the embryo and endosperm in seeds of the stenoendemics <i>S. amici-petri</i>, <i>S. dolomiticola</i>, and <i>S. hornadensis</i>. The tetraploids <i>S. amici-petri</i> and <i>S. hornadensis</i> are characterized by regular and highly stainable pollen grains and reproduce predominantly via pseudogamous apomixis. In contrast, triploid <i>S. dolomiticola</i> usually has oval, heterogenous, and weakly stainable pollen grains, suggesting male meiotic irregularities. Although seeds originate via pseudogamous apomixis in <i>S. dolomiticola</i> as well, the ploidy level of sperm cells participating in the fertilization of central cells is usually determined by co-occurring species of different cytotypes. This suggests that maintaining mating partners is necessary for the long-term survival of a triploid species. We documented rare B<sub>III</sub> hybrids and the residual sexuality in tetraploids. The distribution of seeds of meiotic and apomeiotic origins in <i>S. amici-petri</i> shows bimodal characteristics; however, genotypes with predominantly sexual seed types are rare. Reproduction modes documented in polyploid stenoendemics of <i>Sorbus</i> and inferred microevolutionary intercytotype relationships highlight the mixed-cytotype populations as the source of biodiversity in apomictic plant complexes. We suggest that conservation efforts should focus on maintaining the species and cytotypic diversity of <i>Sorbus</i> populations, especially when it comes to the conservation of triploid species. |
| first_indexed | 2024-03-09T11:24:41Z |
| format | Article |
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| last_indexed | 2024-03-09T11:24:41Z |
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| spelling | doaj.art-b3696d18e23044e7917d178bac54cbeb2023-12-01T00:05:49ZengMDPI AGPlants2223-77472023-01-0112237310.3390/plants12020373Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe)Vladislav Kolarčik0Mária Mirková1Vlastimil Mikoláš2Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, SlovakiaInstitute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University, Mánesova 23, SK-041 54 Košice, SlovakiaIndependent Researcher, Hanojská 4, SK-040 13 Košice, SlovakiaThe remarkable species diversity of the genus <i>Sorbus</i> is a result of polyploidization and frequent hybridization between interacting species of different cytotypes. Moreover, hybridization is possible between several parental taxa. Gametophytic apomixis, which is common among polyploid <i>Sorbus</i> taxa, indicates the role of clonal reproduction in the evolutionary stabilization of hybridogeneous genotypes. The precise determination of the origin of seeds and their quantitative evaluation may elucidate inter-cytotype interactions, the potential role of mixed-cytotype populations in evolutionary success, and the long-term survival of some hybrid species. We investigated the reproduction modes of selected species of <i>Sorbus</i> in mixed-cytotype populations in eastern Slovakia, Central Europe. We determined the pollen quality, seed production rate, and the ploidy level of mature trees, as well as the origin of the embryo and endosperm in seeds of the stenoendemics <i>S. amici-petri</i>, <i>S. dolomiticola</i>, and <i>S. hornadensis</i>. The tetraploids <i>S. amici-petri</i> and <i>S. hornadensis</i> are characterized by regular and highly stainable pollen grains and reproduce predominantly via pseudogamous apomixis. In contrast, triploid <i>S. dolomiticola</i> usually has oval, heterogenous, and weakly stainable pollen grains, suggesting male meiotic irregularities. Although seeds originate via pseudogamous apomixis in <i>S. dolomiticola</i> as well, the ploidy level of sperm cells participating in the fertilization of central cells is usually determined by co-occurring species of different cytotypes. This suggests that maintaining mating partners is necessary for the long-term survival of a triploid species. We documented rare B<sub>III</sub> hybrids and the residual sexuality in tetraploids. The distribution of seeds of meiotic and apomeiotic origins in <i>S. amici-petri</i> shows bimodal characteristics; however, genotypes with predominantly sexual seed types are rare. Reproduction modes documented in polyploid stenoendemics of <i>Sorbus</i> and inferred microevolutionary intercytotype relationships highlight the mixed-cytotype populations as the source of biodiversity in apomictic plant complexes. We suggest that conservation efforts should focus on maintaining the species and cytotypic diversity of <i>Sorbus</i> populations, especially when it comes to the conservation of triploid species.https://www.mdpi.com/2223-7747/12/2/373apomixisCentral Europeendemismfertilizationflow cytometryhybridization |
| spellingShingle | Vladislav Kolarčik Mária Mirková Vlastimil Mikoláš Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) Plants apomixis Central Europe endemism fertilization flow cytometry hybridization |
| title | Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) |
| title_full | Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) |
| title_fullStr | Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) |
| title_full_unstemmed | Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) |
| title_short | Reproduction Modes and Conservation Implications in Three Polyploid <i>Sorbus</i> Stenoendemics in Eastern Slovakia (Central Europe) |
| title_sort | reproduction modes and conservation implications in three polyploid i sorbus i stenoendemics in eastern slovakia central europe |
| topic | apomixis Central Europe endemism fertilization flow cytometry hybridization |
| url | https://www.mdpi.com/2223-7747/12/2/373 |
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