Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Database
Language
Publication year range
1.
Heliyon ; 10(5): e26906, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38434263

ABSTRACT

The increased movement of humans throughout the world allowed the transportation of several species, such as Moringa oleifera Lam. (moringa), into biomes far away from their native habitation. Native to India, moringa is a versatile, drought-tolerant, and fast-growing tree that is easily adaptable to wide-ranging tropical and sub-tropical conditions around the world. It is used in cosmetics, as food and medicine for humans, livestock feed, crop biostimulant, and green manure. Even though moringa is an alien species to South Africa, its production is increasing, and its numerous uses are recognised by communities. Moringa forms part of a highly complex (social, ecological, and economic) system. This is because it is on the Species Under Surveillance for Possible Eradication or Containment Targets (SUSPECT) list under the National Environmental Management Biodiversity Act (NEM:BA) of South Africa. Listing species that are regarded as beneficial to communities on national regulations can cause conflicts and uncertainties among various stakeholders (i.e., environmental policymakers, farmers, rural communities, and government bodies). In this paper, a systems thinking approach was applied to address complex and conflicting issues linked to the production and overall status (economic, ecological, legal, and social) of moringa in South Africa. The Causal Loop Diagram (CLD) was developed to present a broad insight into the complexity of moringa in South Africa and assist in underscoring the feedback mechanisms within the system. Moreover, the CLD indicated that the position of moringa within the country comprised a variety of interdependent variables of government policies, environment, and society, which are interconnected into a multifaceted system. The potential conflict dimensions and types associated with allocating moringa an impact category within the South African context were identified, and this may serve as a useful tool for facilitating engagements and decision-making processes among stakeholders in resolving the status of moringa in South Africa.

2.
Biodivers Data J ; 12: e99555, 2024.
Article in English | MEDLINE | ID: mdl-38328409

ABSTRACT

Background: Ants are one of the most ubiquitous, widespread and abundant groups of animals on Earth. They are eusocial and are well noted for their important ecosystem services such as nutrient recycling, seed dispersal, engaging in mutualistic associations with other organisms, as well as serving as predators and scavengers. Although Africa has been recognised as a global hotspot for ant diversity, African ant genera are not as well-known when compared with other regions. The last checklist of Nigerian ants was compiled and published in the 1970s. To contribute to new knowledge on West African ant genera and Nigeria in particular, we conducted a review of the ant species of Nigeria using 132 scientific publications mostly compiled in the database www.antmaps.org, along with a survey of ant species of Lagos and Oyo States in Nigeria which was conducted between 2018 and 2020. The study aimed to ascertain the diversity of Nigerian ant genera, as well as to confirm the presence of previously recorded species and add new species to the current checklist of Nigerian ants, based on the 1970 survey. New information: As many as 106 species were recorded from the survey in the current study, of which 28 are new to Nigeria and additional 28 are identified to the morphospecies level. In total, 317 species from 10 subfamilies and 64 genera are now recorded from Nigeria, including 11 invasive ants, of which six are new to Nigeria. The following eleven species that were included in the 1970 checklist were excluded from the current list, mostly due to previous misidentifications: Aenictusrotundatus Mayr, 1901; Anochetusjonesi Arnold, 1926; Camponotusbarbarossamicipsa Wheeler, 1992; Camponotusforaminosusdorsalis Santschi, 1926; Camponotusrufoglaucus (Jerdon, 1851); Cardiocondylazoserka Bolton, 1982; Messorbarbarus (Linnaeus, 1767); Odontomachushaematodus (Linnaeus, 1758); Technomyrmexalbipes (Smith, 1861); Tetramoriumdecem Forel, 1913 and Tetraponerapenzigi (Mayr, 1907).

3.
Data Brief ; 51: 109633, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37846331

ABSTRACT

A greenhouse tunnel in Stellenbosch, South Africa was used for testing a generic sensing system for monitoring and control of climatic conditions in the tunnel. Three temperature and humidity sensors were used to record data throughout the day in 5 min intervals. Bambara Nuts, a climate change-resilient and nutritious crop, were grown in a separate study in the tunnel using an aeroponics system. These were chosen as it is regarded as the norm in autonomous greenhouse temperature control in the region. During data collection, the sensors were placed at the front, middle, and back of the tunnel. At the front, there was an industrial extraction fan, and at the back, there was an evaporative cooling wet wall. The fan and wet wall were controlled using the middle sensor data that was averaged every minute to determine if the fan and wet wall should be on or off. The hysteresis band used as a threshold was to turn the fan on when the middle temperature reached 30 °C and to turn it off it was 22 °C. This data collection method extended from 31 December 2022 to 13 June 2023, collecting 162 days of temperature and humidity data for that period.

4.
Heliyon ; 9(3): e14675, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37101470

ABSTRACT

Global agricultural production is currently limited by negative climate-related hazards such as drought, uneven rainfall and rising temperatures. Many efforts have been put in place by government and non-government agencies to mitigate the challenges of climate change in the sector. However, the approaches do not seem feasible due to the growing demand for food. With these challenges, climate-smart agricultural technologies such as aeroponics and underutilised crops have been projected as the future of agriculture in developing African countries to reduce the risk of food insecurity. In this paper, we present the cultivation of an underutilised indigenous African legume crop, Bambara groundnut, in an aeroponics system. Seventy Bambara groundnut landraces were cultivated in a low-cost climate-smart aeroponics system and in sawdust media. The results showed that Bambara groundnut landraces cultivated in aeroponics performed better than those cultivated in a traditional hydroponics (sawdust/drip irrigation) technique in terms of plant height and chlorophyll content, where the landraces cultivated in sawdust had a higher number of leaves than those cultivated in aeroponics. This study also demonstrated the feasibility of introducing a generic Internet of Things platform for climate-smart agriculture in developing countries. The proof-of-concept and the successful cultivation of a hypogeal crop in aeroponics can be useful for cost-effective adaptation and mitigation plans for climate change, particularly for food security in rural African agricultural sectors.

5.
Sci Rep ; 9(1): 15114, 2019 10 22.
Article in English | MEDLINE | ID: mdl-31641159

ABSTRACT

The role of starch degradation in non-vascular plants is poorly understood. To expand our knowledge of this area, we have studied this process in Physcomitrella patens. This has been achieved through examination of the step known to initiate starch degradation in angiosperms, glucan phosphorylation, catalysed by glucan, water dikinase (GWD) enzymes. Phylogenetic analysis indicates that GWD isoforms can be divided into two clades, one of which contains GWD1/GWD2 and the other GWD3 isoforms. These clades split at a very early stage within plant evolution, as distinct sequences that cluster within each were identified in all major plant lineages. Of the five genes we identified within the Physcomitrella genome that encode GWD-like enzymes, two group within the GWD1/GWD2 clade and the others within the GWD3 clade. Proteins encoded by both loci in the GWD1/GWD2 clade, named PpGWDa and PpGWDb, are localised in plastids. Mutations of either PpGWDa or PpGWDb reduce starch phosphate abundance, however, a mutation at the PpGWDa locus had a much greater influence than one at PpGWDb. Only mutations affecting PpGWDa inhibited starch degradation. Mutants lacking this enzyme also failed to develop gametophores, a phenotype that could be chemically complemented using glucose supplementation within the growth medium.


Subject(s)
Bryopsida/growth & development , Bryopsida/metabolism , Germ Cells, Plant/growth & development , Glucans/genetics , Mutation/genetics , Phosphotransferases (Paired Acceptors)/genetics , Starch/metabolism , Water/metabolism , Amino Acid Sequence , Bryopsida/genetics , Genome, Plant , Isoenzymes/metabolism , Phosphorylation , Phosphotransferases (Paired Acceptors)/chemistry , Phylogeny , Plastids/metabolism , Solubility
6.
Syst Biol ; 64(4): 549-67, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25649930

ABSTRACT

Phylogenetic reconstruction, divergence time estimations and ancestral range estimation were undertaken for 66% of the Afrotropical freshwater crab fauna (Potamonautidae) based on four partial DNA loci (12S rRNA, 16S rRNA, cytochrome oxidase one [COI], and histone 3). The present study represents the most comprehensive taxonomic sampling of any freshwater crab family globally, and explores the impact of paleodrainage interconnectivity on cladogenesis among freshwater crabs. Phylogenetic analyses of the total evidence data using maximum-likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) produced a robust statistically well-supported tree topology that reaffirmed the monophyly of the Afrotropical freshwater crab fauna. The estimated divergence times suggest that the Afrotropical Potamonautidae diverged during the Eocene. Cladogenesis within and among several genera occurred predominantly during the Miocene, which was associated with major tectonic and climatic ameliorations throughout the region. Paleodrainage connectivity was observed with specimens from the Nilo-Sudan and East African coast proving to be sister to specimens from the Upper Guinea Forests in West Africa. In addition, we observed strong sister taxon affinity between specimens from East Africa and the Congo basin, including specimens from Lake Tanganyika, while the southern African fauna was retrieved as sister to the Angolan taxa. Within the East African clade we observed two independent transoceanic dispersal events, one to the Seychelles Archipelago and a second to Madagascar, while we observe a single transoceanic dispersal event from West Africa to São Tomé. The ancestral area estimation suggested a West African/East African ancestral range for the family with multiple dispersal events between southern Africa and East Africa, and between East Africa and Central Africa The taxonomic implications of our results are discussed in light of the widespread paraphyly evident among a number of genera.


Subject(s)
Animal Distribution , Brachyura/classification , Brachyura/physiology , Phylogeny , Africa , Animals , Brachyura/genetics , Electron Transport Complex IV/genetics , Fresh Water , Genes, rRNA/genetics , Geography , Histones/genetics , Time
7.
J Plant Physiol ; 171(17): 1609-18, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25151130

ABSTRACT

During P deficiency, the increased activity of malate dehydrogenase (MDH, EC 1.1.1.37) can lead to malate accumulation. Cytosolic- and nodule-enhanced MDH (cMDH and neMDH, respectively) are known isoforms, which contribute to MDH activity in root nodules. The aim of this study was to investigate the role of the cMDH isoforms in nodule malate supply under P deficiency. Nodulated lupins (Lupinus angustifolius var. Tanjil) were hydroponically grown at adequate P (+P) or low P (-P). Total P concentration in nodules decreased under P deficiency, which coincided with an increase in total MDH activity. A consequence of higher MDH activity was the enhanced accumulation of malate derived from dark CO2 fixation via PEPC and not from pyruvate. Although no measurable neMDH presence could be detected via PCR, gene-specific primers detected two 1kb amplicons of cMDH, designated LangMDH1 (corresponding to +P, HQ690186) and LangMDH2 (corresponding to -P, HQ690187), respectively. Sequencing analyses of these cMDH amplicons showed them to be 96% identical on an amino acid level. There was a high degree of diversification between proteins detected in this study and other known MDH proteins, particularly those from other leguminous plants. Enhanced malate synthesis in P-deficient nodules was achieved via increased anaplerotic CO2 fixation and subsequent higher MDH activities. Novel isoforms of cytosolic MDH may be involved, as shown by gene expression of specific genes under P deficiency.


Subject(s)
Lupinus/enzymology , Malate Dehydrogenase/genetics , Malates/metabolism , Phosphorus/deficiency , Amino Acid Sequence , Base Sequence , Cytosol/enzymology , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Plant/chemistry , DNA, Plant/genetics , Hydroponics , Isoenzymes , Lupinus/genetics , Malate Dehydrogenase/metabolism , Molecular Sequence Data , Nitrogen Fixation , Phosphorus/metabolism , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , RNA, Plant/genetics , Root Nodules, Plant/enzymology , Root Nodules, Plant/genetics , Sequence Alignment , Sequence Analysis, DNA
SELECTION OF CITATIONS
SEARCH DETAIL
...