Environmental aridity is associated with cytotype segregation and polyploidy occurrence in Brachypodium distachyon (Poaceae).
Environmental aridity is associated with cytotype segregation and polyploidy occurrence in Brachypodium distachyon (Poaceae).
复制标题
DOI：
10.1111/j.1469-8137.2011.03988.x
复制
发表时间：
2012-02
期刊：
影响因子：
--
通讯作者：
Mitchell-Olds T
中科院分区：
文献类型：
--
作者：
Manzaneda AJ;Rey PJ;Bastida JM;Weiss-Lehman C;Raskin E;Mitchell-Olds T
植物多倍化的生态和适应意义尚未得到很好的理解，多倍体频率与环境之间也没有明确的关联模式。气候因素有望预测细胞型分布。然而，气候、细胞型分布和非生物耐逆性状变异之间的关系很少被研究。在这里，我们使用流式细胞术和根尖压片来研究分布在伊比利亚半岛干旱梯度上的57个自然种群中温带一年生草本植物Brachypodium disachyon的细胞型分布。我们进一步研究了环境干旱、倍性、耐旱性变异和避旱(开花时间)性状之间的联系。在本种中的二倍体(2n=10)和异源四倍体(2n=30)的分布在伊比利亚半岛的整个范围内的地理结构，并与干旱梯度有关。重要的是，在控制了地理和海拔影响之后，干旱和多倍化发生之间的联系仍然存在。水分利用效率因倍性水平而异，在水分限制条件下，四倍体的水分利用效率高于二倍体。我们的结果表明，干旱是多倍体发生的一个重要预测因子，这可能是细胞型分离的一个适应性起源。
The ecological and adaptive significance of plant polyploidization is not well understood and no clear pattern of association between polyploid frequency and environment has emerged. Climatic factors are expected to predict cytotype distribution. However, the relationship between climate, cytotype distribution and variation of abiotic stress tolerance traits has rarely been examined. Here, we use flow cytometry and root-tip squashes to examine the cytotype distribution in the temperate annual grass Brachypodium distachyon in 57 natural populations distributed across an aridity gradient in the Iberian Peninsula. We further investigate the link between environmental aridity, ploidy, and variation of drought tolerance and drought avoidance (flowering time) traits. istribution of diploids (2n = 10) and allotetraploids (2n = 30) in this species is geographically structured throughout its range in the Iberian Peninsula, and is associated with aridity gradients. Importantly, after controlling for geographic and altitudinal effects, the link between aridity and polyploidization occurrence persisted. Water use efficiency varied between ploidy levels, with tetraploids being more efficient in the use of water than diploids under water-restricted growing conditions. Our results indicate that aridity is an important predictor of polyploid occurrence in B. distachyon, suggesting a possible adaptive origin of the cytotype segregation.