多倍体化是开花植物进化分歧的普遍机制。多倍体谱系的生态分歧已被提出作为塑造自然界中细胞类型分布的关键过程(生态位转移假说);然而,仍然需要证据证明生态位分离在复制的二倍体-多倍体物种对中的作用。本研究旨在评估非生物因素对当前细胞类型分布的影响。为此,我们研究了在整个物种范围内以及伊比利亚半岛假定的接触区内,在二倍体-四倍体Jasionemaritima中识别的两个品种的分布和环境生态位。我们计数了染色体,筛选整个伊比利亚半岛的倍性,并使用生态位建模工具表征环境要求。我们找到了J.maritimavar.maritima由二倍体组成,分布在法国西海岸和伊比利亚半岛西北部,伊比利亚半岛的四倍体,而var.sabularia是四倍体。在伊比利亚半岛,沿线性沿海分布的两个副儿科接触区被检测到,二倍体和四倍体var之间的一个。maritima,另一个在两个品种的四倍体之间。法国二倍体种群的环境变量与南部二倍体种群的环境变量不同,更类似于四倍体。总的来说,生态位建模结果与观察到的分布模式一致,尽管结果表明品种和细胞类型之间有更广泛的接触区域。与二倍体对应物相比,两个品种的四倍体都显示出不同程度的环境差异。四倍体var。sabularia在环境上与二倍体不同,表明生态位差异。相比之下,四倍体var.maritima与二倍体环境生态位重叠,目前占据了整个预测范围,而二倍体仅限于其合适环境的北部地区。生态包络的差异有助于识别多倍体群体中生物多样性的功能单元,允许研究与多倍体化后分歧相关的因素。因此,而环境要求的变化可能允许四倍体var。sabularia在不利于二倍体的栖息地传播,二倍体和四倍体var的分布与其他因素有关。maritima.
Polyploidization is a widespread mechanism of evolutionary divergence in flowering plants. Ecological divergence of polyploid lineages has been proposed as a key process shaping the distribution of cytotypes in nature (niche shift hypothesis); however, evidence for the role of niche separation in replicated diploid-polyploid species pairs is still needed. This study aimed to assess the role of abiotic factors shaping current cytotype distributions. For that, we examined the distribution and environmental niches of two varieties recognized in diploid-tetraploid Jasione maritima across the species range and within a putative contact zone on the Iberian Peninsula. We counted chromosomes, screened for ploidy across Iberian Peninsula and characterized environmental requirements using niche modeling tools. We found that J. maritima var. maritima is composed by diploids with disjunct distribution in the west coast of France and northwest Iberian Peninsula, and by
tetraploids in Iberian Peninsula, while var. sabularia is tetraploid. In the Iberian Peninsula, two parapatric contact zones along a linear coastal distribution were detected, one between diploid and tetraploid var. maritima, and the other between
tetraploids of the two varieties. Environmental variables of diploid populations from France are distinct from those of southern diploid populations, which are more similar to
tetraploids. In general, niche modeling results are congruent with the observed distribution patterns, although the results suggest a wider contact zone between varieties and cytotypes.
Tetraploids of both varieties revealed different degrees of environmental divergence in comparison with their diploid counterpart. Tetraploid var. sabularia differed environmentally from diploids suggesting niche divergence. In contrast, tetraploid var. maritima overlapped with diploid environmental niche and currently occupies its entire predicted range, whereas diploids are restricted to northern areas of their suitable environment. Differences in ecological envelopes facilitate the recognition of functional units of biodiversity within polyploid groups, allowing the study of factors related to post-polyploidization divergence. Thus, whereas changes in environmental requirements may have allowed tetraploid var. sabularia to spread in habitats not favorable to diploids, other factors are involved with the distribution of diploid and tetraploid var. maritima.