Mechanisms of reproductive isolation of interspecific hybridization between Trillium camschatcense and T.tschonoskii (Melanthiaceae)
Mechanisms of reproductive isolation of interspecific hybridization between Trillium camschatcense and T.tschonoskii (Melanthiaceae)
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DOI：
10.1111/j.1442-1984.2012.00378.x
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发表时间：
2013-09-01
影响因子：
1.4
通讯作者：
Ohara, Masashi
中科院分区：
文献类型：
--
作者：
Ishizaki, Satomi;Abe, Tamayo;Ohara, Masashi
生殖隔离在防止不同植物物种之间的基因流动方面发挥着重要作用。隔离因素可能会有所不同，在合子前或合子后发挥作用。延龄草和延龄草是多年生草本植物，经常在日本北海道一起生长。这些物种之间的自然杂交 T.xhagae 很常见，并且以 T.camschatcense 作为母本和 T.tschonoskii 作为父本不对称地发生。在这里，我们检查了每个生殖隔离因素的效率，以阐明哪个因素导致杂交的频率和不对称性。我们发现，自体受精和同种花粉优先等合子前障碍是两个亲本物种的主要隔离因素，并且 T.tschonoskii 作为母本比 T.camschatcense 具有更有效的合子前障碍。此外，以T.tschonoskii为母本的杂交种未观察到达到开花期。我们得出的结论是，两个物种中的合子前隔离因子是阻止自然杂交的主要障碍，并且这些物种之间隔离屏障的不对称性将促进 T.camschatcense 作为杂种的母本。
Reproductive isolation plays a significant role in the prevention of gene flow between different plant species. Isolation factors can vary, acting either pre- or postzygotically. Trillium camschatcense and T.tschonoskii are herbaceous perennials which frequently grow together in Hokkaido, Japan. Natural hybrid formation, T.xhagae, between these species is common, and occurs asymmetrically with T.camschatcense as the maternal parent and T.tschonoskii as the paternal. Here, we examined the efficiency of each reproductive isolation factor to clarify which factor was responsible for the frequency and asymmetry of the hybridization. We found that prezygotic barriers, self fertilization and conspecific pollen precedence, are major isolation factors in both parental species, and that T.tschonoskii as a maternal parent has more effective prezygotic barriers than T.camschatcense. In addition, hybrids with T.tschonoskii as the maternal parent were not observed to reach the flowering stage. We concluded that prezygotic isolation factors in the both species act as main barriers to prevent natural hybridization, and that asymmetry of the isolating barriers between these species would promote T.camschatcense as the maternal parent of the hybrids.