期刊
ANNALS OF BOTANY
卷 105, 期 4, 页码 527-533出版社
OXFORD UNIV PRESS
DOI: 10.1093/aob/mcq008
关键词
Polyploidy; speciation; Spartina; nonaploid; nonaploid bridge; interspecific hybridization; GISH
资金
- French National Research Agency (ANR)
- Natural Environment Research Council [NE/C511964/1] Funding Source: researchfish
Background The genus Spartina exhibits extensive hybridization and includes classic examples of recent speciation by allopolyploidy. In the UK there are two hexaploid species, S. maritima and S. alterniflora, as well as the homoploid hybrid S. x townsendii (2n = 60) and a derived allododecaploid S. anglica (2n = 120, 122, 124); the latter two are considered to have originated in Hythe, southern England at the end of the 19th century. Methods Genomic in situ hybridization (GISH) and flow cytometry were used to characterize the genomic composition and distribution of these species and their ploidy levels at Eling Marchwood and Hythe, both near Southampton, southern England. Key Results GISH identified approx. 60 chromosomes each of S. maritima and S. alterniflora origin in S. anglica and 62 chromosomes from S. alterniflora and 30 chromosomes from S. maritima in a nonaploid individual from Eling Marchwood, UK. GISH and flow cytometry also revealed that most (94%) individuals examined at Hythe were hexaploid (the remaining two individuals (6%) were dodedcaploid; n = 34), whereas hexaploid (approx. 36% of plants), nonaploid (approx. 27 %) and dodecaploid (approx. 36 %) individuals were found at Eling Marchwood (n 22). Conclusions Nonaploid individuals indicate the potential for introgression between hexaploid and dodecaploid species, complicating the picture of polyploid-induced speciation within the genus. Despite the aggressive ecological habit of S. anglica, it has not out-competed S. x townsendii at Hythe (homoploid hybrids at a frequency of 94 %, n = 34), despite > 100 years of coexistence. The success of GISH opens up the potential for future studies of polyploid-induced genome restructuring in this genus.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据