Pollen competition among two species of Senecio (Asteraceae) that form a hybrid zone on Mt. Etna, Sicily
Pollen competition among two species of Senecio (Asteraceae) that form a hybrid zone on Mt. Etna, Sicily
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DOI：
10.3732/ajb.92.4.730
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发表时间：
2005-04-01
影响因子：
3
通讯作者：
Abbott, RJ
中科院分区：
文献类型：
--
作者：
Chapman, MA;Forbes, DG;Abbott, RJ
同种花粉优势（CPA）可以显著减少可育、同域或近域植物物种之间的杂交，由此同种花粉在胚珠受精方面比异种花粉具有优势。我们研究了千里光属两种可育种的CPA，S。aethnensis和S. chalcifolius（菊科），在Mt.西西里的埃特纳。这两个物种的个人授粉与花粉混合物含有0，25 - 50，75，或100%的异源花粉，后代进行基因分型，以确定他们是否是同种或异源花粉的产物。在S. Aethnensis植物与基于施加到花头上的异种花粉的比例所预期的没有显著不同。然而，S.白菊母株表现出中等的CPA，杂交后代的比例明显低于预期。种子的结实率和发芽率没有降低，因此，S.小叶章作用于胚珠受精前。CPA的不对称性对S. acethnensis的简要讨论，沿着与其他机制，可能发挥作用的混合区的维护山。埃特纳。
Hybridization between interfertile, sympatric or parapatric, plant species can be reduced significantly by conspecific pollen advantage (CPA), whereby conspecific pollen has an advantage over heterospecific pollen in terms of ovule fertilization. We examined CPA in two interfertile species of Senecio, S. aethnensis, and S. chrysanthemifolius (Asteraceae), which form a hybrid zone on Mt. Etna, Sicily. Individuals of both species were pollinated with pollen mixtures containing 0, 25 50, 75, or 100% heterospecific pollen, and offspring were genotyped to determine if they were products of conspecific or heterospecific pollen fertilizing the ovules. The mean proportion of hybrid offspring produced on S. aethnensis plants was not significantly different to that expected based on the proportion of heterospecific pollen applied to the flower head. However, S. chrysanthemifolius mother plants showed moderate CPA, with the proportion of hybrid offspring significantly less than expected. Seed set or seed germination was not reduced, hence the CPA found for S. chrysanthemifolius acts before ovule fertilization. The consequences of asymmetry in CPA on the reproductive isolation of S. aethnensis are briefly discussed, along with other mechanisms that may play a role in the maintenance of the hybrid zone on Mt. Etna.