Elizabeth Syowai Mutinda

Evolutionary relationships in Zanthoxylum L. and Vepris Comm. ex A. Juss. remain poorly resolved due to limited genomic resources and conflicting signals from individual markers, hindering efforts to understand their diversification and adaptation across tropical environments. In this study, we generated Angiosperms353 target‐capture data for 187 individuals representing 51 Zanthoxylum and Vepris species from East Africa. Using concatenated and multispecies coalescent analyses combined with concordance‐factor approaches, we recovered Zanthoxylum and Vepris as monophyletic clades. However, species‐level relationships within each genus exhibited substantial phylogenetic discordance. Concordance factor analysis revealed moderate genome‐wide site concordance (mean sCF = 46.64%) but markedly lower gene concordance (mean gCF = 28.76%), indicating widespread gene‐tree heterogeneity. Both sCF and gCF exhibited strong positive correlations with branch lengths; r = 0.698 and r = 0.687, respectively. Discordance patterns showed an almost perfect balance between alternative topologies (sDF1 = 24.9%, sDF2 = 24.8%), minimal mean asymmetry (3.5%–5.1%), and a high proportion of polyphyly (gDFP = 59.7%), all consistent with incomplete lineage sorting (ILS) as the primary source of phylogenomic conflict. A small fraction of branches (1.9%–4.7%) displayed significant asymmetry, which signals only limited evidence for processes beyond ILS and should be interpreted with caution pending explicit tests of introgression. Generally, our findings offer a comprehensive phylogenomic framework for East African Zanthoxylum and Vepris and demonstrate that ILS has played a major role in shaping genomic variation and phylogenetic discordance within these genera. Further analyses are required to investigate the extent to which hybridization or other reticulate processes have contributed to their evolutionary history.

The genus Sambucus belongs to the family Viburnaceae, and has long been a debatable taxon regarding its systematics and taxonomic assignment. It is known for its morphological and genetic variations and thus the taxonomic delimitation remains uncertain. Phenotypic and genotypic variations within plant species causes difficulties in the detection of species boundaries. In the present review, we compiled a set of studies that assessed species discrimination within Sambucus genus by morphological and molecular markers as well as the taxonomic uncertainties in the re-circumscription of the segregated genera i.e., Viburnum L., Sambucus L., and Adoxa L., (syn. Sinadoxa C.Y. Wu, Z.L. Wu & R.F. Huang/Tetradoxa C.Y. Wu) from Caprifoliaceae and their family assignment. The data was obtained from published journal articles and various online databases. Morphological and molecular diagnostic characters were employed to distinguish Sambucus species. Our findings indicated that high intraspecific variations within narrow-ranged populations and their widespread counterparts contribute to its taxonomic complications. Additionally, intraspecific variations within Sambucus species leads to misidentifications and the misapplication of names, occasioning the publication of many putative synonyms and ambiguous names. Possible interspecific hybridizations experienced between Sambucus species increases complexity in character evolution. A morphological analysis showed that the endocarp seed morphological characters can reliably support the segregation of Sambucus taxa into discrete taxonomic entities. In molecular analysis, the NeighborNet (NN) phylogenetic split network revealed three distinct genera including Viburnum, Sambucus, and Adoxa, which clustered separately. The Maximum Likelihood (ML) analysis indicated that the Sambucus species formed a monophyletic group and clustered into two major clades, a small clade containing S. maderensis, S. peruviana, S. nigra, and S. canadensis, and a large clade encompassing the rest of the species with significantly supported clades (Sambucus is Viburnaceae.

Background: Calanthe(Epidendroideae, Orchidaceae) is a pantropical genus distributed in Asia and Africa. Its species are of great importance in terms of economic, ornamental and medicinal values. However, due to limited and confusing delimitation characters, the taxonomy of theCalanthealliance (Calanthe,Cephalantheropsis, andPhaius) has not been sufficiently resolved. Additionally, the limited genomic information has shown incongruences in its systematics and phylogeny. In this study, we used illumina platform sequencing, performed ade novoassembly, and did a comparative analysis of 8Calanthegroup species' plastomes: 6Calantheand 2Phaiusspecies. Phylogenetic analyses were used to reconstruct the relationships of the species as well as with other species of the family Orchidaceae.Results: The complete plastomes of theCalanthegroup species have a quadripartite structure with varied sizes ranging between 150,105bp-158,714bp, including a large single-copy region (LSC; 83,364bp- 87,450bp), a small single-copy region (SSC; 16,297bp -18,586bp), and a pair of inverted repeat regions (IRs; 25,222bp - 26,430bp). The overall GC content of these plastomes ranged between 36.6-36.9%. These plastomes encoded 131-134 differential genes, which included 85-88 protein-coding genes, 37-38 tRNA genes, and 8 rRNA genes. Comparative analysis showed no significant variations in terms of their sequences, gene content, gene order, sequence repeats and the GC content hence highly conserved. However, some genes were lost inC.delavayi(P. delavayi), includingndhC,ndhF, andndhKgenes. Compared to the coding regions, the non-coding regions had more sequence repeats hence important for species DNA barcoding. Phylogenetic analysis revealed a paraphyletic relationship in theCalanthegroup, and confirmed the position ofPhaius delavayiin the genusCalantheas opposed to its previous placement inPhaius.Conclusion: This study provides a report on the complete plastomes of 6Calantheand 2Phaiusspecies and elucidates the structural characteristics of the plastomes. It also highlights the power of plastome data to resolve phylogenetic relationships and clarifies taxonomic disputes among closely related species to improve our understanding of their systematics and evolution. Furthermore, it also provides valuable genetic resources and a basis for studying evolutionary relationships and population genetics among orchid species.

Blechnum L. is a genus belonging to the Blechnaceae family with 236 accepted species that grow in intertropical, subtropical, and southern temperate regions. Several species of the genus have long been used in folk medicines to treat a broad spectrum of ailments, including typhoid, urinary infections, influenza, wounds, pulmonary complaints, blisters, boils, and antihelmintic-related complications. So far, about 91 chemical compounds have been isolated from different parts of 20 Blechnum species. Among these metabolites, phenolic compounds, sterols, and fatty acids are the main constituents. Modern pharmacological investigations revealed several isolated compounds and extracts to exhibit exceptional biological properties including the antioxidant, antimicrobial, anti-inflammatory, anticancer, insecticidal, antitrematocidal and wound healing. In various tests, both quercetin-7′,3′,4′-trimethoxy and phytol metabolites showed potential antioxidant and antitrematocidal properties, while ponasterone exhibited insecticidal activity. Despite having a broad range of traditional medicinal benefits and biological properties, understanding the scientific connotations based on the available data is still challenging. This article presents a comprehensive review of the traditional uses, phytochemical compounds, and pharmacological aspects of the Blechnum species.

In the present study, two samples of Toddalia asiatica species, both collected from Kenya, were sequenced and comparison of their genome structures carried out with T. asiatica species from China, available in the NCBI database. The genome size of both species from Africa was 158, 508 base pairs, which was slightly larger, compared to the reference genome of T. asiatica from Asia (158, 434 bp). The number of genes was 113 for both species from Africa, consisting of 79 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. Toddalia asiatica from Asia had 115 genes with 81 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. Both species compared displayed high similarity in gene arrangement. The gene number, orientation, and order were highly conserved. The IR/SC boundary structures were the same in all chloroplast genomes. A comparison of pairwise sequences indicated that the three regions (trnH-psbA, rpoB, and ycf1) were more divergent and can be useful in developing effective genetic markers. Phylogenetic analyses of the complete cp genomes and 79 protein-coding genes indicated that the Toddalia species collected from Africa were sister to T. asiatica collected from Asia. Both species formed a sister clade to the Southwest Pacific and East Asian species of Zanthoxylum. These results supported the previous studies of merging the genus Toddalia with Zanthoxylum and taxonomic change of Toddalia asiatica to Zanthoxylum asiaticum, which should also apply for the African species of Toddalia. Biogeographic results demonstrated that the two samples of Toddalia species from Africa diverged from T. asiatica from Asia (3.422 Mya, 95% HPD). These results supported an Asian origin of Toddalia species and later dispersal to Africa and Madagascar. The maxent model analysis showed that Asia would have an expansion of favorable areas for Toddalia species in the future. In Africa, there will be contraction and expansion of the favorable areas for the species. The availability of these cp genomes will provide valuable genetic resources for further population genetics and biogeographic studies of these species. However, more T. asiatica species collected from a wide geographical range are required.