Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy?
Androdioecy is a rare reproductive system. <i>Fraxinus platypoda</i>, a woody canopy species in Japan’s mountainous riparian zones, is described as a morphologically androdioecious species. In this study, we tried to detect whether <i>F. platypoda</i> is also functionally and...
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MDPI AG
2022-03-01
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| Online Access: | https://www.mdpi.com/2223-7747/11/6/753 |
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| author | Hitoshi Sakio Takashi Nirei |
| author_facet | Hitoshi Sakio Takashi Nirei |
| author_sort | Hitoshi Sakio |
| collection | DOAJ |
| description | Androdioecy is a rare reproductive system. <i>Fraxinus platypoda</i>, a woody canopy species in Japan’s mountainous riparian zones, is described as a morphologically androdioecious species. In this study, we tried to detect whether <i>F. platypoda</i> is also functionally androdioecious. We analyzed its sexual expression, seed development, pollen morphology and germination ability, pollination systems, and mast flowering behavior. We found that the hermaphrodite trees are andromonoecious, with inflorescences bearing male and hermaphroditic flowers, whereas male individuals had only male flowers. Pollen morphology was identical in male flowers, in hermaphrodite flowers of an andromonoecious individual, and in male flowers of male individuals. Pollen from both types of individuals was capable of germination both ex vivo (on nutrient medium) and in vivo in pollination experiments. However, compared with pollen from andromonoecious trees, pollen from male trees showed a higher germination rate. The self-pollination rate of bagged hermaphroditic flowers was almost zero. The fruit set rate following cross-pollination with male pollen from a male tree was higher than that following natural pollination, whereas the rate with hermaphroditic pollen was the same. The flowering and fruiting of <i>F. platypoda</i> have fluctuated over 17 years; the flowering of the two types of sexual individuals exhibited clear synchronization during this period. The frequency of male individuals within the populations is 50%. The maintenance of such a proportion of males in populations of the self-incompatible <i>F. platypoda</i> is either indicative of a true androdioecious species with a diallelic self-incompatibility system or a cryptic-dioecious species. This alternative is discussed here. |
| first_indexed | 2024-03-09T12:56:28Z |
| format | Article |
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| language | English |
| last_indexed | 2024-03-09T12:56:28Z |
| publishDate | 2022-03-01 |
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| series | Plants |
| spelling | doaj.art-fed931f6a1cb4fd8a3bbdb5343a97ff62023-11-30T22:00:35ZengMDPI AGPlants2223-77472022-03-0111675310.3390/plants11060753Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy?Hitoshi Sakio0Takashi Nirei1Sado Island Center for Ecological Sustainability, Niigata University, Sado 952-2206, JapanSaitama Museum of Natural History, Nagatoro 369-1305, JapanAndrodioecy is a rare reproductive system. <i>Fraxinus platypoda</i>, a woody canopy species in Japan’s mountainous riparian zones, is described as a morphologically androdioecious species. In this study, we tried to detect whether <i>F. platypoda</i> is also functionally androdioecious. We analyzed its sexual expression, seed development, pollen morphology and germination ability, pollination systems, and mast flowering behavior. We found that the hermaphrodite trees are andromonoecious, with inflorescences bearing male and hermaphroditic flowers, whereas male individuals had only male flowers. Pollen morphology was identical in male flowers, in hermaphrodite flowers of an andromonoecious individual, and in male flowers of male individuals. Pollen from both types of individuals was capable of germination both ex vivo (on nutrient medium) and in vivo in pollination experiments. However, compared with pollen from andromonoecious trees, pollen from male trees showed a higher germination rate. The self-pollination rate of bagged hermaphroditic flowers was almost zero. The fruit set rate following cross-pollination with male pollen from a male tree was higher than that following natural pollination, whereas the rate with hermaphroditic pollen was the same. The flowering and fruiting of <i>F. platypoda</i> have fluctuated over 17 years; the flowering of the two types of sexual individuals exhibited clear synchronization during this period. The frequency of male individuals within the populations is 50%. The maintenance of such a proportion of males in populations of the self-incompatible <i>F. platypoda</i> is either indicative of a true androdioecious species with a diallelic self-incompatibility system or a cryptic-dioecious species. This alternative is discussed here.https://www.mdpi.com/2223-7747/11/6/753androdioecyandromonoecious treediallelic self-incompatibility (DSI)dioecy<i>Fraxinus platypoda</i>male tree |
| spellingShingle | Hitoshi Sakio Takashi Nirei Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? Plants androdioecy andromonoecious tree diallelic self-incompatibility (DSI) dioecy <i>Fraxinus platypoda</i> male tree |
| title | Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? |
| title_full | Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? |
| title_fullStr | Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? |
| title_full_unstemmed | Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? |
| title_short | Is the High Proportion of Males in a Population of the Self-Incompatible <i>Fraxinus platypoda</i> (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy? |
| title_sort | is the high proportion of males in a population of the self incompatible i fraxinus platypoda i oleaceae indicative of true androdioecy or cryptic dioecy |
| topic | androdioecy andromonoecious tree diallelic self-incompatibility (DSI) dioecy <i>Fraxinus platypoda</i> male tree |
| url | https://www.mdpi.com/2223-7747/11/6/753 |
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