Molecular and Morphological Data Improve the Classification of Plantagineae (Lamiales)

Abstract

The tribe Plantagineae (Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy and still unresolved natural history. We describe the result of a broadly sampled phylogenetic study of tribe. The expanded sampling dataset is based on the trnL-F spacer, rbcL, and ITS2 markers across all three included genera (Aragoa, Littorella and Plantago) and makes this the most comprehensive study to date. The other dataset uses five markers and provides remarkably good resolution throughout the tree, including support for all of the major clades. In addition to the molecular phylogeny, a morphology database of 114 binary characters was assembled to provide comparison with the molecular phylogeny and to develop a means to assign species not sampled in the molecular analysis to their most closely related species that were sampled. Based on the molecular phylogeny and the assignment algorithm to place unsampled species, a key to sections is presented, and a revised classification of the tribe is provided. We also include the description of new species from North America.

Complete Mitogenomes of Two Aragoa Species and Phylogeny of Plantagineae (Plantaginaceae, Lamiales) Using Mitochondrial Genes and the Nuclear Ribosomal RNA Repeat

“…The nuclear and mitochondrial datasets examined here (Figure 2) represent the largest sets of nuclear and mitochondrial genes for Plantagineae phylogenetics. In general, the results of these analyses are consistent in several respects with previous analyses based on whole plastid genomes [8], single plastid genes, and/or the nuclear ITS [3][4][5]10], and a combined analysis of five mitochondrial, plastid, and nuclear loci [10]. Collectively, these studies demonstrate that Plantagineae is monophyletic, with Aragoa and Littorella as successive sisters to a monophyletic Plantago.…”

“…Based on analyses of nuclear ITS, various plastid genes, or the entire plastid genome [3][4][5][6][7][8], Aragoa was shown to be sister to Plantago (~250 species) and Littorella (three species), which altogether make up the Plantagineae [6]. Recently, whole plastome data [8,9] and combined 5-loci analyses from all three plant genomes [10] have shown promise for resolving relationships among Plantagineae and within Plantago. However, sampling of nuclear and mitochondrial loci has been limited to nuclear ITS [3][4][5][6]10] and single mitochondrial genes [10,11].…”

“…Recently, whole plastome data [8,9] and combined 5-loci analyses from all three plant genomes [10] have shown promise for resolving relationships among Plantagineae and within Plantago. However, sampling of nuclear and mitochondrial loci has been limited to nuclear ITS [3][4][5][6]10] and single mitochondrial genes [10,11]. Thus, it is currently unclear whether the plastome results are congruent with the phylogenetic signal in the mitochondrial and nuclear genomes.…”

Taxonomic fingerprints of Plantago atrata Hoppe – a Review

“…Phylogenetic studies supported by morphological and molecular data had assigned P. atrata to subgenus Albicans Rahn section Montana Barnéoud [3], [35], [36]. The species that were in a cluster with P. atrata Hoppe included P. nivalis Boiss., as well as P. cafra Decne.…”

“…Among the molecular markers, the nuclear ribosomal ITS2 and the plastid trnL-F intergenic spacer regions appeared as the most corresponding to the morphological characteristics of subg. Albicans [35], [36].…”