One or more species in the arctic grass genus Dupontia? -: a contribution to the Panarctic Flora project
One or more species in the arctic grass genus Dupontia? -: a contribution to the Panarctic Flora project
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作者：
Brysting, AK;Fay, MF;Aiken, SG
禾本科（Poaceae）是北极地区最大的维管植物家族。该科包括几个物种复合体，表现出高倍性水平，主要是无性繁殖，形态界限不清，并有可能起源于北极地区的网状进化。基于泛北极植物群研究的需要和目前分类学上的分歧，本研究采用分子和细胞遗传学方法对北极草属杜邦属进行了研究。相同的质体DNA（trnL-F）序列和非常相似的AFLP图谱表明，杜邦和Arctophila是密切相关的，后者可能参与了一个可能的属间杂交起源杜邦。尽管存在的个体内rDNA（ITS）的变化，表明异源多倍体杂交起源的属，它是不可能预测的第二个亲本物种的序列数据或荧光原位杂交（FISH）实验，使用基因组探针。由于缺乏序列的分歧Dupontia，AFLP指纹分析，以调查是否有任何遗传细分存在于该属。数据分类Dupontia首先根据地理，而不是倍性或形态特征，以前已被用来区分拟议的类群。研究结果表明，单种多态性的识别是解决杜邦属的最佳方案。
The grass family (Poaceae) is the largest family of vascular plants in the Arctic. The family includes several species complexes that show high ploidy levels, predominantly reproduce asexually, are poorly morphologically delimited, and have a possible origin within the Arctic area by reticulate evolution. Challenged by work on the Panarctic Flora project and apparent discrepancies in recent taxonomic treatments, we investigated the arctic grass genus Dupontia by molecular and cytogenetic methods. Identical plastid DNA (trnL-F) sequences and very similar AFLP profiles indicated that Dupontia and Arctophila are closely related and that the latter might have been involved in a possible intergeneric hybrid origin of Dupontia. Despite the presence of intraindividual rDNA (ITS) variation in Dupontia indicating an allopolyploid hybrid origin of the genus, it was not possible to predict the second parental species from sequence data or from fluorescent in situ hybridization (FISH) experiments using genomic probes. Due to lack of sequence divergence within Dupontia, AFLP fingerprinting was applied to investigate whether any genetic subdivision exists within the genus. The data sorted Dupontia first of all according to geography and not to ploidy or morphological characters that have previously been used to discriminate between proposed taxa. The results indicate that the recognition of a single polymorphic species is the best solution for the genus Dupontia.