Genomic relationships between the cultivated peanut (Arachis hypogaea, Leguminosae) and its close relatives revealed by double GISH
Genomic relationships between the cultivated peanut (Arachis hypogaea, Leguminosae) and its close relatives revealed by double GISH
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DOI：
10.3732/ajb.94.12.1963
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发表时间：
2007-12-01
影响因子：
3
通讯作者：
Moscone, Eduardo A.
中科院分区：
文献类型：
--
作者：
Seijo, Guillermo;Lavia, Graciela I.;Moscone, Eduardo A.
花生是一种自然存在的异源四倍体(AABB)，其2n=40。然而，研究人员对二倍体基因组供体物种以及花生是由单个还是多个多倍化事件起源的问题存在分歧。在这里，我们利用双重GISH(基因组原位杂交)技术为花生的遗传起源和涉及的野生近缘提供证据。测试了7个野生二倍体物种(2n=20)，它们都含有A或B基因组。在所分析的所有基因组DNA探针组合中，杜兰木耳(A基因组)和伊帕木(B基因组)似乎是基因组供体的最佳候选者，因为当它们与山杨的相应染色体亚组进行杂交时，它们产生了最强烈和最均匀的杂交模式。在栽培原的所有品种中都观察到了类似的GISH模式，对蒙蒂科拉也是如此。这些结果表明，目前已知的所有亚种和变种都来自一个独特的异源四倍体植物种群，或者是来自同一两个二倍体物种的不同异源四倍体种群。此外，大部分数据表明这两个四倍体之间存在密切的基因组关系，并有力地支持了蒙古拉黑线姬松茸是黑曲霉的直接野生先驱者的假设。
Arachis hypogaea is a natural, well-established allotetraploid (AABB) with 2n = 40. However, researchers disagree on the diploid genome donor species and on whether peanut originated by a single or multiple events of polyploidization. Here we provide evidence on the genetic origin of peanut and on the involved wild relatives using double GISH (genomic in situ hybridization). Seven wild diploid species (2n=20), harboring either the A or B genome, were tested. Of all genomic DNA probe combinations assayed, A. duranensis (A genome) and A. ipaensis (B genome) appeared to be the best candidates for the genome donors because they yielded the most intense and uniform hybridization pattern when tested against the corresponding chromosome subsets of A. hypogaea. A similar GISH pattern was observed for all varieties of the cultigen and also for A. monticola. These results suggest that all presently known subspecies and varieties of A. hypogaea have arisen from a unique allotetraploid plant population, or alternatively, from different allotetraploid populations that originated from the same two diploid species. Furthermore, the bulk of the data demonstrated a close genomic relationship between both tetraploids and strongly supports the hypothesis that A. monticola is the immediate wild antecessor of A. hypogaea.