Salinity, not genetic incompatibilities, limits the establishment of the invasive hybrid cattail Typha × glauca in coastal wetlands

A single pair of co-existing species that can successfully hybridize may produce many more hybrids in some regions than in others. The reasons for this are not well understood, but could help explain processes such as species diversification or the range expansion of invasive hybrids.  The widespread cattails Typha latifolia and T. angustifolia seldom hybridize in some parts of their range, but in other areas produce the dominant hybrid T. × glauca.  We used a combination of field and greenhouse experiments to investigate why T. × glauca has invaded wetlands in the Laurentian Great Lakes region of southern Ontario, Canada, but is much less common in the coastal wetlands of NS in eastern Canada.  One potentially important environmental difference between these two regions is salinity.  We therefore tested three hypotheses: 1) T. latifolia and T. angustifolia in NS are genetically incompatible; 2) the germination or growth of T. × glauca is reduced by salinity; and 3) T. latifolia, a main...

一对可成功杂交的共存物种，在部分区域产生的杂交子代数量往往远多于其他区域。该现象的成因尚未完全明晰，但其相关机制或可解释物种多样化、入侵性杂交类群的范围扩张等生态学过程。广为分布的香蒲属植物宽叶香蒲（Typha latifolia）与狭叶香蒲（Typha angustifolia），在其分布范围的部分区域极少发生杂交，但在其他区域则会形成优势杂交种灰香蒲（Typha × glauca）。我们结合野外调查与温室控制实验，探究为何灰香蒲（Typha × glauca）能够成功入侵加拿大安大略省南部圣劳伦斯五大湖区域的湿地，却在加拿大东部新斯科舍省（NS）的滨海湿地中极为罕见。这两个区域间一项潜在的关键环境差异为盐度。因此我们验证了三项假说：1）新斯科舍省的宽叶香蒲与狭叶香蒲存在遗传不相容性；2）盐度会抑制灰香蒲的萌发或生长；3）宽叶香蒲作为主要……