Phylogenetic Systematics of Convolvulaceae

The Convolvulaceae, a family of roughly 2,000 species across some 60 genera, encompasses ecologically and economically significant plants such as the sweet potato (Ipomoea batatas), ornamental morning glories, bindweeds and parasitic dodders (Cuscuta). Phylogenetic systematics seeks to reconstruct the evolutionary history and relationships within this diverse lineage by integrating molecular data—chiefly chloroplast and nuclear genomes—with morphological evidence. Early studies based predominantly on a handful of chloroplast markers provided a broad outline of major clades but left key relationships among subfamilies, tribes and genera unresolved. More recent genomic approaches, leveraging complete plastome sequencing and high‐throughput nuclear gene capture, have begun to resolve deep splits, confirm the placement of aberrant lineages such as Cuscuta within Convolvulaceae and reveal instances of reticulation and polyploidy. These insights underpin a revised framework for classification, inform divergence‐time estimates dating the radiation of major clades to the Oligocene–Miocene, and guide conservation priorities for rare and endemic species. Ongoing efforts unite global taxonomic sampling with phylogenomics to refine tribal delimitation, understand hybrid origins and support applications ranging from crop improvement to biodiversity management.

Research from Nature Portfolio

A recent chloroplast genome comparison of two Ipomoea species has provided a comprehensive view of plastome organisation and divergence within a key clade. Both genomes exhibit the typical quadripartite structure of inverted repeats separating large and small single‐copy regions, and reveal conserved gene content alongside hotspots of variation in accD, ndhA and ndhF coding regions and intergenic spacers. Analyses of simple sequence repeats and codon usage bias highlight selective pressures shaping plastid genes. Phylogenetic reconstruction using complete plastome and coding‐region datasets resolves sectional relationships within Ipomoea and, through molecular dating, estimates divergence times for major tribes (c. 30, 20 and 13 million years ago) as well as for splits among focal species around 10–17 Mya. These results strengthen the plastome backbone for subsequent phylogenomic studies.

Phylogenetic Systematics of Convolvulaceae publication trend

The graph below shows the total number of articles in phylogenetic systematics of convolvulaceae across all publications each year (not limited to Nature Index journals).

Technical terms

Phylogenetic systematics: The study of evolutionary relationships among organisms, using data to reconstruct lineage divergence and classification.

Chloroplast genome (plastome): The circular DNA within chloroplasts, often used in plant phylogenetics due to its conserved structure and gene content.

Inverted repeat (IR): Two identical sequences in reverse orientation that separate the large and small single-copy regions in plastid genomes.

Monophyly: A grouping of organisms that includes an ancestor and all its descendants, reflecting a single evolutionary lineage.

Allopolyploidy: The formation of a polyploid organism by hybridisation between two distinct species, combining divergent genomes.

References

1. The chloroplast genome sequences of Ipomoea alba and I. obscura (Convolvulaceae): genome comparison and phylogenetic analysis. Scientific Reports (2024).
2. A Bird’s Eye View of the Systematics of Convolvulaceae: Novel Insights From Nuclear Genomic Data. Frontiers in Plant Science (2022).
3. Cuscuta seeds: Diversity and evolution, value for systematics/identification and exploration of allometric relationships. PLOS ONE (2020).