Polyploid origins in a circumpolar complex in Draba (Brassicaceae) inferred from cloned nuclear DNA sequences and fingerprints
Polyploid origins in a circumpolar complex in Draba (Brassicaceae) inferred from cloned nuclear DNA sequences and fingerprints
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DOI：
10.1016/j.ympev.2004.04.006
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发表时间：
2004-09-01
影响因子：
4.1
通讯作者：
Oxelman, B
中科院分区：
文献类型：
--
作者：
Grundt, HH;Popp, M;Oxelman, B
多倍体进化在北极植物群中具有重要意义，但很少在完整的环极尺度上讨论。在此，我们研究了异源多倍体的马蹄及其密切的盟友，形成了一个复杂的分类学北极高山复合体，包括二倍体，四倍体，和六倍体。基于从整个环极区的样品，我们推断在这个复杂的多倍体的起源使用克隆的DNA序列从两个核区域（一个内含子从一个基因编码的第二大亚基的RNA聚合酶家族，RPD2，和核糖体内部转录间隔区，ITS）和DNA指纹（随机扩增多态性DNA，RAPDs）。虽然D. lactea和其他的多倍体都是具有固定杂合性的遗传异源倍体，本研究所获得的数据表明，这里所分析的每一个多倍体都可能起源于一个二倍体谱系：六倍体D. lactea通过四倍体D. lactea从D. palanderiana谱系（不是D. fladnizensis和D. nivalis谱系），四倍体D. turczaninovii的D. fladnizensis谱系，四倍体D. porsildii来自D. lonchocarpa谱系，以及一个四倍体Draba spB。nivalis血统。在白令地区，可能起源于几次，并且没有必要像以前建议的那样，基于不同物种谱系的组合来援引复杂的起源。(C)2004爱思唯尔公司All rights reserved.
Polyploid evolution has been of major importance in the arctic flora, but rarely addressed on the full circumpolar scale. Herein we study the allopolyploid Draba lactea and its close allies, which form a taxonomically intricate arctic-alpine complex including diploids, tetraploids, and hexaploids. Based on samples from the entire circumpolar area, we inferred the origins of polyploids in this complex using cloned DNA sequences from two nuclear regions (one intron from a gene encoding a second largest subunit in the RNA polymerase family, RPD2, and the ribosomal internal transcribed spacer region, ITS) and DNA fingerprints (random amplified polymorphic DNAs, RAPDs). Although D. lactea and all other polyploids examined in Draba are genetic alloploids showing fixed heterozygosity, the data obtained in the present study suggest that each of the polyploids analyzed here may have originated from a single diploid lineage: hexaploid D. lactea via tetraploid D. lactea from the D. palanderiana lineage (not from the D. fladnizensis and D. nivalis lineages as previously hypothesized), the tetraploid D. turczaninovii from the D. fladnizensis lineage, the tetraploid D. porsildii from the D. lonchocarpa lineage, and a tetraploid here named Draba spB from the D. nivalis lineage. Draba lactea has probably originated several times in the Beringian area, and it is not necessary to invoke complex origins based on a combination of different species lineages as previously suggested. (C) 2004 Elsevier Inc. All rights reserved.