ECOLOGICAL FACTORS INFLUENCING TETRAPLOID SPECIATION IN SNOW BUTTERCUPS (RANUNCULUS ADONEUS): NICHE DIFFERENTIATION AND TETRAPLOID ESTABLISHMENT
ECOLOGICAL FACTORS INFLUENCING TETRAPLOID SPECIATION IN SNOW BUTTERCUPS (RANUNCULUS ADONEUS): NICHE DIFFERENTIATION AND TETRAPLOID ESTABLISHMENT
复制标题
影响雪毛茛（毛茛）四倍体形成的生态因素：生态位分化和四倍体建立
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
M. Stanton
中科院分区：
文献类型：
--
作者：
E. Baack;M. Stanton
摘要：染色体加倍在开花植物新物种的形成中起着重要作用。然而，新形成的四倍体植物与其二倍体祖先之间的生殖不相容性预计会对新多倍体种群的持续存在和建立造成重大障碍。生态分化可通过空间分离产生的合子前隔离来降低这一障碍。或者，新四倍体植物的更强生存能力或繁殖力可能弥补来自二倍体邻居的不相容花粉所带来的生殖成本。可以通过相互移植在各自的生境中评估两种细胞型植物的表现，尽管此类实验此前尚未用于四倍体物种形成的研究中。我们通过一系列种子和幼苗移植实验，评估了雪毛茛（Ranunculus adoneus）四倍体和二倍体形式在早期建立阶段的生态分化和竞争能力。在两个地点，二倍体和四倍体的种子具有相似的发芽概率。在受控环境室实验中，四倍体雪毛茛幼苗具有显著的生长优势。然而，在野外，二倍体和四倍体毛茛幼苗在存活或生长方面并没有始终表现出差异，两种细胞型在表现上也没有如生态分化发生时所预期的那种相互优势。在种子和幼苗阶段，生态位分化和四倍体竞争优势似乎都不足以解释在其二倍体祖先存在的情况下新四倍体的成功。
Abstract Chromosome doubling plays an important role in generating new species of flowering plants. However, reproductive incompatibilities between newly formed tetraploid plants and their diploid progenitors are expected to create a significant barrier to the persistence and establishment of neopolyploid populations. Ecological differentiation can reduce this barrier via prezygotic isolation arising from spatial separation. Alternatively, superior viability or fecundity of neotetraploid plants might compensate for the reproductive cost of incompatible pollen from diploid neighbors. The performance of plants of both cytotypes can be assessed in their respective habitats through reciprocal transplants, although such experiments have not been used previously in the study of tetraploid speciation. We used a series of seed and seedling transplant experiments to assess ecological differentiation and competitive ability during early establishment phases for tetraploid and diploid forms of the snow buttercup (Ranunculus adoneus). At two sites, seeds from diploids and tetraploids had similar germination probabilities. Tetraploid snow buttercup seedlings had a significant growth advantage in a controlled environment chamber experiment. However, in the field diploid and tetraploid buttercup seedlings did not differ consistently in survival or growth, nor did the two cytotypes show reciprocal advantages in performance, as expected if ecological differentiation has occurred. At the seed and seedling stages, neither niche differentiation nor tetraploid competitive superiority appears sufficient to explain neotetraploid success in the presence of their diploid progenitors.