ISOLATION BARRIERS BETWEEN PETUNIA AXILLARIS AND PETUNIA INTEGRIFOLIA (SOLANACEAE)
ISOLATION BARRIERS BETWEEN PETUNIA AXILLARIS AND PETUNIA INTEGRIFOLIA (SOLANACEAE)
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DOI：
10.1111/j.1558-5646.2011.01279.x
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发表时间：
2011-07-01
期刊：
影响因子：
3.3
通讯作者：
Kuhlemeier, Cris
中科院分区：
文献类型：
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作者：
Dell'Olivo, Alexandre;Hoballah, Maria Elena;Kuhlemeier, Cris
限制种群或物种之间基因流动的隔离屏障对于理解生物物种如何产生以及如何维持至关重要。很少有研究探讨了整个范围内可能的隔离障碍，从地理隔离到下一代杂交的可行性。在这里，我们提出了一个详细的分析隔离障碍的两种开花植物属矮牵牛（茄科）。矮牵牛和腋花矮牵牛具有不同的授粉综合征，但在实验室中杂交时可以产生可育的杂种。这两种矮牵牛主要是孤立的空间，但似乎不杂交同域。我们的实验表明，传粉者隔离是非常高的，但不足以解释自然界中没有杂种。然而，传粉者隔离与雄性配子隔离（即，花粉-雌蕊相互作用）可以解释自然杂交的缺乏，而合子后隔离障碍很低或不存在。我们的研究支持这样的观点，即开花植物的生殖隔离主要是由前，而不是后合子隔离机制。
The isolation barriers restricting gene flow between populations or species are of crucial interest for understanding how biological species arise and how they are maintained. Few studies have examined the entire range of possible isolation barriers from geographic isolation to next generation hybrid viability. Here, we present a detailed analysis of isolation barriers between two flowering plant species of the genus Petunia (Solanaceae). Petunia integrifolia and P. axillaris feature divergent pollination syndromes but can produce fertile hybrids when crossed in the laboratory. Both Petunia species are primarily isolated in space but appear not to hybridize in sympatry. Our experiments demonstrate that pollinator isolation is very high but not strong enough to explain the absence of hybrids in nature. However, pollinator isolation in conjunction with male gametic isolation (i.e., pollen-pistil interaction) can explain the lack of natural hybridization, while postzygotic isolation barriers are low or nonexistent. Our study supports the notion that reproductive isolation in flowering plants is mainly caused by pre- rather than postzygotic isolation mechanisms.