Rhipsalis baccifera is the only cactus that naturally occurs in both the New World and the Old World, and has thus drawn the attention of most researchers. The complete chloroplast (cp) genome of R. baccifera is reported here for the first time. The cp genome of R. baccifera has 122, 333 base pairs (bp), with a large single-copy (LSC) region (81,459 bp), SSC (23,531 bp) and two inverted repeat (IR) regions each 8530 bp. The genome contains 110 genes, with 73 protein-coding genes, 31 tRNAs, 4 rRNAs and 2 pseudogenes. Twelve genes have introns, with loss of introns being observed in, rpoc1clpP and rps12 genes. 49 repeat sequences and 62 simple sequence repeats (SSRs) were found in the genome. Comparative analysis with eight species of the ACPT (Anacampserotaceae, Cactaceae, Portulacaceae, and Talinaceae) clade of the suborder Portulacineae species, showed that R. baccifera genome has higher number of rearrangements, with a 19 gene inversion in its LSC region representing the most significant structural change in terms of its size. Inversion of the SSC region seems common in subfamily Cactoideae, and another 6 kb gene inversion between rbcL- trnM was observed in R. baccifera and Carnegiea gigantea. The IRs of R. baccifera are contracted. The phylogenetic analysis among 36 complete chloroplast genomes of Caryophyllales species and two outgroup species supported monophyly of the families of the ACPT clade. R. baccifera occupied a basal position of the family Cactaceae clade in the tree. A high number of rearrangements in this cp genome suggests a larger number mutation events in the history of evolution of R. baccifera. These results provide important tools for future work on R. baccifera and in the evolutionary studies of the suborder Portulacineae.
Detailed morphological and molecular research has led to the conclusion that the majority of the species of the genus Brachiaria have to move to the much smaller genus Urochloa . Although many of the necessary new combinations were made, in Africa a fair number of accepted species still do not yet have a name within Urochloa . Following work on West Africa, Central Africa and Madagascar, this paper now provides these new combinations for the remaining sub-Saharan African species, as well as a full synonymy for all East African ones, including typification. In total, the paper deals with 40 species, for 12 of these new combinations are created, while 55 lectotypes and one neotype of both accepted names and synonyms are designated.
Climate change poses a serious long-term threat to biodiversity. To effectively reduce biodiversity loss, conservationists need to have a thorough understanding of the preferred habitats of species and the variables that affect their distribution. Therefore, predicting the impact of climate change on species-appropriate habitats may help mitigate the potential threats to biodiversity distribution.
Globally, endemic species and natural habitats have been significantly impacted by climate change, and further considerable impacts are predicted. Therefore, understanding how endemic species are impacted by climate change can aid in advancing the necessary conservation initiatives. The use of niche modeling is becoming a popular topic in biological conservation to forecast changes in species distributions under various climate change scenarios. This study used the Australian Community Climate and Earth System Simulator version 1 (ACCESS-CM2) general circulation model of coupled model intercomparison project phase 6 (CMIP6) to model the current distribution of suitable habitat for the four threatened Annonaceae species endemic to East Africa (EA), to determine the impact of climate change on their suitable habitat in the years 2050 (average for 2041-2060) and 2070 (average for 2061-2080). Two shared socio-economic pathways (SSPs) SSP370 and SSP585 were used to project the contraction and expansion of suitable habitats for Uvariodendron kirkii, Uvaria kirkii, Uvariodendron dzomboense and Asteranthe asterias endemic to Kenya and Tanzania in EA. The current distribution for all four species is highly influenced by precipitation, temperature, and environmental factors (population, potential evapotranspiration, and aridity index). Although the loss of the original suitable habitat is anticipated to be significant, appropriate habitat expansion and contraction are projections for all species. More than 70% and 40% of the original habitats of Uvariodendron dzombense and Uvariodendron kirkii are predicted to be destroyed by climate change, respectively. Based on our research, we suggest that areas that are expected to shrink owing to climate change be classified as important protection zones for the preservation of Annonaceae species.
Traditional medicinal plants have been used for decades in folk medicines in the treatment and management of several ailments and diseases including diabetes, pain, ulcers, cancers, and wounds, among others. This study focused on the phytochemical and antidiabetic activity of the commonly used antidiabetic medicinal species in Kenya. Phytochemical profiling of these species revealed flavonoids and terpenoids as the major chemical classes reported which have been linked with strong biological activities against the aforementioned diseases, among others. However, out of the selected twenty-two species, many of the natural product isolation studies have focused on only a few species, as highlighted in the study. All of the examined crude extracts from thirteen antidiabetic species demonstrated strong antidiabetic activities by inhibiting α-glucosidase and α-amylase among other mechanisms, while nine are yet to be evaluated for their antidiabetic activities. Isolated compounds S-Methylcysteine sulfoxide, quercetin, alliuocide G, 2-(3,4-Dihydroxybenzoyl)-2,4,6-trihydroxy-3 (2H)-benzofuranone, Luteolin-7-O-D-glucopyranoside, quercetin, 1,3,11α-Trihydroxy-9-(3,5,7-trihydroxy-4H-1-benzopyran-7-on-2-yl)-5α-(3,4-dihydroxy-phenyl)-5,6,11-hexahydro-5,6,11-trioxanaphthacene-12-one and [1,3,11α-Trihydroxy-9-(3,5,7-trihydroxy-4H-1-benzopyran-7-on-2-yl)-5α-(3,4-dihydroxy-phenyl)-5,6,11-hexahydro-5,6,11-trioxanaphthacene-12-one]-4′-O-D-gluco-pyranoside from Allium cepa have been found to exhibit significant antidiabetic activities. With the huge number of adults living with diabetes in Kenya and the available treatment methods being expensive yet not so effective, this study highlights alternative remedies by documenting the commonly used antidiabetic medicinal plants. Further, the study supports the antidiabetic use of these plants with the existing pharmacological profiles and highlights research study gaps. Therefore, it is urgent to conduct natural products isolation work on the selected antidiabetic species commonly used in Kenya and evaluate their antidiabetic activities, both in vitro and in vivo, to validate their antidiabetic use and come up with new antidiabetic drugs.
The complete chloroplast genome sequence of Xerophyta spekei Baker was reported in this study. The complete chloroplast genome showed a stereotypical quadripartite structure as observed in other angiosperms with a length of 155,235 bp and divided into four parts; a pair of IRs (27,109 bp) which is separated by a small single copy (SSC) region (17,388 bp) and a large single copy (LSC) region (83,629bp). The chloroplast genome had 132 genes, including 85 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Seven protein-coding genes were identified to have RNA editing.
The genus Chlorophytum includes many economically important species well-known for medicinal, ornamental, and horticultural values. However, to date, few molecular genomic resources have been reported for this genus. Therefore, there is limited knowledge of phylogenetic studies, and the available chloroplast (cp) genome of Chlorophytum (C. rhizopendulum) does not provide enough information on this genus. In this study, we present genomic resources for C. comosum and C. gallabatense, which had lengths of 154,248 and 154,154 base pairs (bp), respectively. They had a pair of inverted repeats (IRa and IRb) of 26,114 and 26,254 bp each in size, separating the large single-copy (LSC) region of 84,004 and 83,686 bp from the small single-copy (SSC) region of 18,016 and 17,960 bp in C. comosum and C. gallabatense, respectively. There were 112 distinct genes in each cp genome, which were comprised of 78 protein-coding genes, 30 tRNA genes, and four rRNA genes. The comparative analysis with five other selected species displayed a generally high level of sequence resemblance in structural organization, gene content, and arrangement. Additionally, the phylogenetic analysis confirmed the previous phylogeny and produced a phylogenetic tree with similar topology. It showed that the Chlorophytum species (C. comosum, C. gallabatense and C. rhizopendulum) were clustered together in the same clade with a closer relationship than other plants to the Anthericum ramosum. This research, therefore, presents valuable records for further molecular evolutionary and phylogenetic studies which help to fill the gap in genomic resources and resolve the taxonomic complexes of the genus.
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 the Calanthe alliance (Calanthe, Cephalantheropsis, and Phaius) 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 a de novo assembly, and did a comparative analysis of 8 Calanthe group species' plastomes: 6 Calanthe and 2 Phaius species. Phylogenetic analyses were used to reconstruct the relationships of the species as well as with other species of the family Orchidaceae.The complete plastomes of the Calanthe group 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 in C. delavayi (P. delavayi), including ndhC, ndhF, and ndhK genes. 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 the Calanthe group, and confirmed the position of Phaius delavayi in the genus Calanthe as opposed to its previous placement in Phaius.This study provides a report on the complete plastomes of 6 Calanthe and 2 Phaius species 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.