Low dispersal and ploidy differences in a grass maintain photosynthetic diversity despite gene flow and habitat overlap
Low dispersal and ploidy differences in a grass maintain photosynthetic diversity despite gene flow and habitat overlap
复制标题
尽管基因流和栖息地重叠，草中的低扩散和倍性差异仍保持光合多样性
DOI：
10.1111/mec.15871
复制
发表时间：
2021
影响因子：
4.9
通讯作者：
P. Christin
中科院分区：
文献类型：
--
作者：
Jill K. Olofsson;E. Curran;Florence Nyirenda;Matheus E. Bianconi;L. Dunning;Vanja Milenković;Graciela Sotelo;O. Hidalgo;R. F. Powell;M. Lundgren;I. Leitch;P. Nosil;C. Osborne;P. Christin
地理隔离有利于出现不同的表型在一个单一的物种，但需要生殖障碍或选择，以保持多态性后，二次接触。在这里，我们探讨的过程中，保持种内变异的C4光合作用，一个复杂的性状，结果从多个基因的联合作用。半翼拟异翅草包括C4和非C4种群，它们作为多倍体系列在非洲的miombo林地共存了100多万年。使用群体基因组学，我们发现光合类型存在全基因组差异，但目前的地理分布并不能反映简单的栖息地迁移情况，因为遗传簇重叠，偶尔会在给定的栖息地内混合。尽管有证据表明非C4和C4群体之间存在反复的基因渗入，但在二倍体和多倍体中，不同的遗传谱系保留了它们的身份，这可能是因为对杂交种的选择。再加上每个遗传组内的距离隔离，这种选择创造了光合类型的地理镶嵌。二倍体C4和非C4类型从不生长在一起，来自混合种群的C4类型始终属于六倍体谱系。通过限制光合类型之间的生殖相互作用，倍性差异可能允许它们共存，加强了该物种内的功能多样性。总之，这些因素使持久的不同的生理特性的生态重要性在一个单一的物种，尽管基因流和栖息地重叠。
Geographical isolation facilitates the emergence of distinct phenotypes within a single species, but reproductive barriers or selection are needed to maintain the polymorphism after secondary contact. Here, we explore the processes that maintain intraspecific variation of C4 photosynthesis, a complex trait that results from the combined action of multiple genes. The grass Alloteropsis semialata includes C4 and non‐C4 populations, which have coexisted as a polyploid series for more than 1 million years in the miombo woodlands of Africa. Using population genomics, we show that there is genome‐wide divergence for the photosynthetic types, but the current geographical distribution does not reflect a simple habitat displacement scenario as the genetic clusters overlap, being occasionally mixed within a given habitat. Despite evidence of recurrent introgression between non‐C4 and C4 groups, in both diploids and polyploids, the distinct genetic lineages retain their identity, potentially because of selection against hybrids. Coupled with strong isolation by distance within each genetic group, this selection created a geographical mosaic of photosynthetic types. Diploid C4 and non‐C4 types never grew together, and the C4 type from mixed populations constantly belonged to the hexaploid lineage. By limiting reproductive interactions between photosynthetic types, the ploidy difference probably allows their co‐occurrence, reinforcing the functional diversity within this species. Together, these factors enabled the persistence of divergent physiological traits of ecological importance within a single species despite gene flow and habitat overlap.
影响因子：
18
作者：
Atkinson, Rebecca R. L.;Mockford, Emily J.;Osborne, Colin P.
通讯作者：
Osborne, Colin P.
影响因子：
3.7
作者：
Abbott, Richard J.
通讯作者：
Abbott, Richard J.