Phylogenetic relationships of diploid and polyploid species in Ludwigia sect. Isnardia (Onagraceae) based on chloroplast and nuclear DNAs

in Sciences Citation Index(SCI), 科學引文索引資料庫(SCI)
標題Phylogenetic relationships of diploid and polyploid species in Ludwigia sect. Isnardia (Onagraceae) based on chloroplast and nuclear DNAs
出版類型SCI(Sciences Citation Index)
出版年度2009
AuthorsKuo-Hsiang Hung, 洪國翔, Barbara A. Schaal B. A. S., Tsai-Wen Hsu 許再文, Yu-Chung Chiang 江友中, Ching-I Peng 彭鏡毅, & Tzen-Yuh Chiang 蔣鎮宇
開始頁1216
頁數9
出版日期2009 / 11
其他編號0000
中文摘要

Ludwigia, a genus with rampant interspecific hybridization, is an ideal model for examining the impact of gene introgression and polyploidization on species diversification.We examined the evolution of the Ludwigia sect. Isnardia, which is a polyploid complex (x = 8) of five species distributed in North America. The phylogeny of L. sect. Isnardia was reconstructed based on sequences of cpDNA atpB-rbcL intergenic spacer and nrITS (internal transcribed spacer). Most L. sect. Isnardia species are polyphyletic at both loci, indicating possible recurrent hybridization, based on maximum likelihood trees rooted at L. sect. Microcarpium. A minimum spanning network was also constructed to examine genealogical relationships among haplotypes. In the cpDNA network, haplotypes of tetraploid L. spathulata are nested at the most interior nodes, suggesting a parental genome origin of an extinct diploid or an unsampled extant diploid with a DD cytotype. Allopolyploid L. arcuata contributed its cpDNA to hexaploid L. repens and L. brevipes. ITS haplotypes of diploid L. palustris were clustered with L. spathulata, suggesting L. palustris as the paternal genome donor. Ludwigia brevipes may have arisen via bi-directional hybridization between L. palustris and L. arcuata followed by polyploidy. Genetic and phylogenetic analyses using molecular markers with different inheritance modes provided sufficient insights into the reticulate evolution of the species of L. sect. Isnardia. Interspecific hybridization and polyploidy play a key role in the species evolution in L. sect. Isnardia.

期刊名稱Taxon
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