PDF(Pubmed)
Abstract：
Angiosperms possess various strategies to ensure reproductive success, such as stylar polymorphisms that encourage outcrossing. Here, we investigate the genetic basis of one such dimorphism that combines both temporal and spatial separation of sexual function, termed flexistyly. It is a floral strategy characterised by the presence of two morphs that differ in the timing of stylar movement. We performed a de novo assembly of the genome of Alpinia nigra using high-depth genomic sequencing. We then used Pool-seq to identify candidate regions for flexistyly based on allele frequency or coverage differences between pools of anaflexistylous and cataflexistylous morphs. The final genome assembly size was 2 Gb, and showed no evidence of recent polyploidy. The Pool-seq did not reveal large regions with high FST values, suggesting large structural chromosomal polymorphisms are unlikely to underlie differences between morphs. Similarly, no region had a 1:2 mapping depth ratio which would be indicative of hemizygosity. We propose that flexistyly is governed by a small genomic region that might be difficult to detect with Pool-seq, or a complex genomic region that proved difficult to assemble. Our genome will be a valuable resource for future studies of gingers, and provides the first steps towards characterising this complex floral phenotype.
摘要：
被子植物拥有各种策略来确保生殖成功，例如鼓励异型杂交的风格多态性。这里,我们调查了一个这样的双态的遗传基础，结合了性功能的时间和空间分离，被称为flexistly。这是一种花卉策略，其特征在于存在两种变体，它们在样式运动的时间上有所不同。我们使用高深度基因组测序对黑姜基因组进行了从头组装。然后，我们使用Pool-seq根据等位基因频率或存在和存在的类群之间的覆盖差异来确定存在的候选区域。最终的基因组组装大小为2Gb，并且没有显示最近多倍体的证据。Pool-seq没有显示具有高FST值的大区域，这表明大的结构染色体多态性不太可能成为形态之间差异的基础。同样，没有区域具有1:2的映射深度比,这将表明半合子。我们建议flexistyly由一个小的基因组区域控制，该区域可能难以用Pool-seq检测到，或者是难以组装的复杂基因组区域.我们的基因组将是未来研究生姜的宝贵资源，并提供了表征这种复杂花卉表型的第一步。
