Biosciences Research Division, Department of Environment and Primary Industries, AgriBio, The Centre for AgriBioscience 5 Ring Road, La Trobe University Research and Development Park, Bundoora, Victoria, 3083, Australia ; Dairy Futures Cooperative Research Centre Bundoora, Victoria, 3086, Australia.
Ecol Evol. 2013 Nov;3(13):4415-26. doi: 10.1002/ece3.828. Epub 2013 Oct 9.
In plant species, control of flowering time is an important factor for adaptation to local natural environments. The Vrn1 , CO , FT1 and CK2α genes are key components in the flowering-specific signaling pathway of grass species. Meadow fescue is an agronomically important forage grass species, which is naturally distributed across Europe and Western Asia. In this study, meadow fescue flowering-time-related genes were resequenced to assess nucleotide diversity in European and Western Asian subpopulations. Identified sequence polymorphisms were then converted into PCR-based molecular genetic markers, and a meadow fescue germplasm collection was genotyped to investigate global allelic variation. Lower nucleotide diversities were observed for the Vrn1 and CO orthologs, while relatively higher values were observed for the FT1 and casein kinase II α-subunit (CK2α) orthologs. The nucleotide diversity for FT1 orthologs in the Western Asian subpopulation was significantly higher than those of the European subpopulation. Similarly, significant differences in nucleotide diversity for the remaining genes were observed between several combinations of subpopulation. The global allele distribution pattern was consistent with observed level of nucleotide diversity. These results suggested that the degree of purifying selection acting on the genes differs according to geographical location. As previously shown for model plant species, functional specificities of flowering-time-related genes may also vary according to environmental conditions.
在植物物种中，开花时间的控制是适应当地自然环境的一个重要因素。Vrn1、CO、FT1 和 CK2α 基因是禾本科植物开花特异性信号通路的关键组成部分。草地羊茅是一种具有重要农艺价值的饲料草种，其自然分布于欧洲和西亚。在这项研究中，对草地羊茅开花时间相关基因进行了重测序，以评估欧洲和西亚亚群的核苷酸多样性。然后将鉴定出的序列多态性转化为基于 PCR 的分子遗传标记，并对草地羊茅种质资源进行基因型分析，以研究全球等位基因变异。Vrn1 和 CO 直系同源物的核苷酸多样性较低，而 FT1 和酪蛋白激酶 II α 亚基（CK2α）直系同源物的核苷酸多样性相对较高。西亚亚群 FT1 直系同源物的核苷酸多样性明显高于欧洲亚群。同样，在几个亚群组合之间，其他基因的核苷酸多样性也存在显著差异。全球等位基因分布模式与观察到的核苷酸多样性一致。这些结果表明，基因受到的纯化选择程度因地理位置而异。正如先前对模式植物物种的研究表明，开花时间相关基因的功能特异性也可能因环境条件而异。
