North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the s...North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.展开更多
Falcaria vulgaris (sickleweed) is native to Eurasia and a potential invasive plant of the United States. No molecular markers have been developed so far for sickleweed. Characterization of molecular markers for this p...Falcaria vulgaris (sickleweed) is native to Eurasia and a potential invasive plant of the United States. No molecular markers have been developed so far for sickleweed. Characterization of molecular markers for this plant would allow investigation into its population structure and biogeography thereby yielding insights into risk analysis and effective management practices of the plant. In order to characterize the molecular markers, DNA samples were collected from eight populations in Iowa, Nebraska and South Dakota. Nuclear microsatellite markers developed for other Apiaceae taxa were screened and tested for intergeneric transferability to sickleweed. The chloroplast trnL intron and trnL-F intergenic spacer regions were sequenced and the sequences were used to design primers to amplify the microsatellites present within each region. We characterized eight polymorphic microsatellite markers for sickleweed that included six nuclear and two chloroplast markers. Our result showed intergeneric transferability of six nuclear microsatellite markers from Daucus carota to F. vulgaris. The markers we characterized are useful for population genetic study of F. vulgaris.展开更多
目的:分析比较石蒜属和近缘属植物中国水仙trnL基因的部分序列和trnL-trnF间隔区的完整序列,为石蒜属物种鉴别和种间亲缘关系分析提供分子佐证。方法:采用PCR产物直接双向测序法,用Clustal X 1.81,MEGA 2.0软件进行序列分析,采用最大简...目的:分析比较石蒜属和近缘属植物中国水仙trnL基因的部分序列和trnL-trnF间隔区的完整序列,为石蒜属物种鉴别和种间亲缘关系分析提供分子佐证。方法:采用PCR产物直接双向测序法,用Clustal X 1.81,MEGA 2.0软件进行序列分析,采用最大简约法(maximum parsimony,MP)构建系统发育树。结果:所测物种的序列全长在905～1036 bp,经排序后,两端切平,得到886 bp的整齐序列,所测物种的核苷酸变异位点14个,信息位点10个,主要在trnL内含子区,这些位点可用于区分石蒜属物种;4个碱基"ATAT"缺失/插入是区别石蒜属与其近缘植物水仙的显著特征。重建的系统发育树表明:供试的石蒜属物种聚成3类,除稻草石蒜、忽地笑、香石蒜的系统位置有所不同之外,与经典分类结果基本相符。水仙属2个种形成1个单系类群,表明属间trnL-F序列差异明显。结论:分子系统树支持安徽石蒜是长筒石蒜的变种或杂交种观点,换锦花可能是玫瑰石蒜、红蓝石蒜的杂交母本。石蒜属种间trnL-F序列存在一定变异,是物种鉴别的有效分子标记。展开更多
文摘North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.
文摘Falcaria vulgaris (sickleweed) is native to Eurasia and a potential invasive plant of the United States. No molecular markers have been developed so far for sickleweed. Characterization of molecular markers for this plant would allow investigation into its population structure and biogeography thereby yielding insights into risk analysis and effective management practices of the plant. In order to characterize the molecular markers, DNA samples were collected from eight populations in Iowa, Nebraska and South Dakota. Nuclear microsatellite markers developed for other Apiaceae taxa were screened and tested for intergeneric transferability to sickleweed. The chloroplast trnL intron and trnL-F intergenic spacer regions were sequenced and the sequences were used to design primers to amplify the microsatellites present within each region. We characterized eight polymorphic microsatellite markers for sickleweed that included six nuclear and two chloroplast markers. Our result showed intergeneric transferability of six nuclear microsatellite markers from Daucus carota to F. vulgaris. The markers we characterized are useful for population genetic study of F. vulgaris.
