scholarly journals Nodulation Compatibility and Symbiotic Performance of Rhizobia spp. With Different Landraces of Bambara Groundnut (Vigna Subterranea (L.) Verdc.) Collections

2022 ◽  
Author(s):  
Ahmed Idris Idris Hassen ◽  
Ansa van Vuuren ◽  
Francina Lebogang Bopape ◽  
Abe Shegro Gerrano
Keyword(s):  
South African ◽  
Plant Biomass ◽  
Principal Component ◽  
Culture Collection ◽  
Bambara Groundnut ◽  
Cyamopsis Tetragonoloba ◽  
Screening Assay ◽  
River Sand ◽  
Nodule Number ◽  
Inoculation Group

Abstract The symbiosis of the legume bambara groundnut (Vigna subterranean L.Verde) with its rhizobial partners has not been studied sufficiently compared to several other legumes throughout Africa. In this study, a nodulation compatibility screening was conducted on 16 different landraces of this legume using five Rhizobia strains previously isolated from active nodules of Desmodium uncinatum, Arachis hypogaea, Cyamopsis tetragonoloba, Glycine max and Phaseolus vulgaris and deposited at the South African Rhizobium Culture Collection (SARCC). A screening assay was conducted under glasshouse to select compatible rhizobia strains that nodulate and enhance growth in one or more genotypes of V. subterranean (L.) Verdc. Pre-germinated seeds of each landraces planted in sterile river sand medium were inoculated with 108 cfu ml-1 of the rhizobial strains (2ml/seed) and monitored with regular watering for six weeks. Parameters such as nodule number, nodule color and positions, plant biomass were determined in test genotypes. Significant differences were observed among landraces in nodule number and plant biomass, and among rhizobial strains in nodule number. Principal component analysis (PCA) showed that root nodule rhizobia strains SARCC-388 and SARCC-578 characterized as Bradyrhizobium zhangiangens and Bradyrhizobium centrosematis, respectively exhibited the highest nodulation compatibility with one or more bambara groundnut landraces. This study demonstrated that many of the bambara landraces did not show nodulation preference to a unique group of rhizobia, confirming that V. subterranean (L) Verdc can be nodulated by more than one species of rhizobia, especially by rhizobia belonging to the cowpea miscellany cross inoculation group.

scholarly journals Soil Nutrient and Vegetation Diversity Patterns of Alpine Wetlands on the Qinghai-Tibetan Plateau

2021 ◽  
Vol 13 (11) ◽  
pp. 6221
Author(s):  
Muyuan Ma ◽  
Yaojun Zhu ◽  
Yuanyun Wei ◽  
Nana Zhao
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Soil Properties ◽  
Soil Ph ◽  
Plant Biomass ◽  
Principal Component ◽  
Vegetation Diversity ◽  
Vegetation Biomass ◽  
Relative Contribution ◽  
The Relationship

To predict the consequences of environmental change on the biodiversity of alpine wetlands, it is necessary to understand the relationship between soil properties and vegetation biodiversity. In this study, we investigated spatial patterns of aboveground vegetation biomass, cover, species diversity, and their relationships with soil properties in the alpine wetlands of the Gannan Tibetan Autonomous Prefecture of on the Qinghai-Tibetan Plateau, China. Furthermore, the relative contribution of soil properties to vegetation biomass, cover, and species diversity were compared using principal component analysis and multiple regression analysis. Generally, the relationship between plant biomass, coverage, diversity, and soil nutrients was linear or unimodal. Soil pH, bulk density and organic carbon were also significantly correlated to plant diversity. The soil attributes differed in their relative contribution to changes in plant productivity and diversity. pH had the highest contribution to vegetation biomass and species richness, while total nitrogen was the highest contributor to vegetation cover and nitrogen–phosphorus ratio (N:P) was the highest contributor to diversity. Both vegetation productivity and diversity were closely related to soil properties, and soil pH and the N:P ratio play particularly important roles in wetland vegetation biomass, cover, and diversity.

Development of a Uniquely South African Leadership Questionnaire

2002 ◽  
Vol 32 (2) ◽  
pp. 9-25 ◽  
Author(s):  
Hermann H. Spangenberg ◽  
Callie C. Theron
Keyword(s):  
South African ◽  
Goodness Of Fit ◽  
Principal Component ◽  
Charismatic Leadership ◽  
Fit Indices ◽  
Confirmatory Factor Analyses ◽  
Leadership Model ◽  
Emerging Leadership ◽  
Confirmatory Factor ◽  
Unit Performance

This paper describes the development of a leadership questionnaire the aim of which is to assess the behaviours required to lead change and transformation, while at the same time managing organisational unit performance effectively. A Delphi technique was used to facilitate the identification and testing of emerging leadership dimensions and items, starting with a three-stage model of charismatic leadership, The resultant leadership model comprises four stages, measured as 21 dimensions. The research questionnaire consists of 235 items. The questionnaire was field tested by means of 360° assessment conducted amongst 189 unit managers from a diverse group of organisations. Seven hundred and fifty completed questionnaires were obtained. Unrestricted principal component analyses were performed on each of the sub-scales (dimensions) to examine the unidimensionality assumption. This procedure resulted in the formation of three additional sub-scales. Item analyses on each of the sub-scales produced highly satisfactory Cronbach Alpha values. Further confirmatory factor analyses using LISREL were conducted on each of the 24 sub-scales. A series of goodness-of-fit indices generally showed satisfactory results. Overall, results indicate that a 96-item questionnaire format consisting of 24 dimensions with four items each (selected on the basis of factor loadings) could be used with confidence. Recommendations are made for further research.

scholarly journals Thermal and mechanical behavior of composite mortars containing natural sorptive clays and fly ash

2019 ◽  
Vol 51 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Anja Terzic ◽  
Lato Pezo ◽  
Ljiljana Milicic ◽  
Nevenka Mijatovic ◽  
Zagorka Radojevic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Mechanical Behavior ◽  
Mechanical Performance ◽  
Thermal Characteristics ◽  
Principal Component ◽  
Effective Dosage ◽  
Factor Space ◽  
Ann Model ◽  
River Sand ◽  
Mineral Additives

Mineral additives are extensively applied as cement replacement materials in both construction concrete and mortar. Fly ash is one of the most commonly utilized additives which improve rheological properties, as well as thermal and mechanical behavior of mortar, and as such it has been widely investigated. This industrial byproduct comprises heavy metals in its composition; therefore further research is needed to optimize its effective dosage. Moreover, certain sorptive clays, such as natural zeolite and bentonite, can prevent migration of toxic elements from fly ash by immobilizing them in their structure. Ten experimental mortars are prepared with Portland cement, river sand and addition of fly ash, zeolite and/or bentonite in accordance with chemometric experimental design rules. The aim of the study was to investigate the effect of mineral additives on thermal and mechanical performances of mortar. Thermal characteristics were monitored via dilatometric analysis and DTA method. Principal component analysis was used on the results of physico-mechanical testing (workability, bulk density, water absorption, shrinkage, compressive and flexural strength) to enable the divisions of the observed samples into groups in the factor space. The performance of Artificial Neural Network was compared with the experimental data in order to develop rapid and accurate method for prediction of mechanical parameters of mortar. The ANN model showed high overall prediction accuracy (r2 = 0.989, during training cycle). The test results indicate that incorporation of the mineral additives gave cost effective mortars with sufficiently good properties. However, tools of analytical modeling highlighted mortar with zeolite and fly ash as the optimal composition regarding its mechanical performance.

scholarly journals Variation of Phenotypic Traits in Twelve Bambara Groundnut (Vigna subterranea (L.) Verdc.) Genotypes and Two F2 Bi-Parental Segregating Populations

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1451
Author(s):  
Xiuqing Gao ◽  
Aliyu Siise Abdullah Bamba ◽  
Aloyce Callist Kundy ◽  
Kumbirai Ivyne Mateva ◽  
Hui Hui Chai ◽  
...  
Keyword(s):  
Southern Africa ◽  
Negative Relationship ◽  
Principal Component ◽  
Bambara Groundnut ◽  
Structured Populations ◽  
Phenotypic Trait ◽  
Phenotypic Traits ◽  
Potential Contribution ◽  
Vigna Subterranea ◽  
East West

Underutilised species such as bambara groundnut (Vigna subterranea (L.) Verdc.) have the potential to contribute significantly to meeting food and nutritional needs worldwide. We evaluated phenotypic traits in twelve bambara groundnut genotypes from East, West and Southern Africa and Southeast Asia and two F2 bi-parental segregating populations derived from IITA-686 ×Tiga Nicuru and S19-3 ×DodR to determine phenotypic trait variation and their potential contribution to the development of improved crop varieties. All phenotypic traits in twelve genotypes were significantly influenced (p < 0.01) by genotypes. Principal component analysis (PCA) showed that PC1 accounted for 97.33% variation and was associated with four genotypes collected from East and Southern Africa. PC2 accounted for 2.48% of the variation and was associated with five genotypes collected from East, West and Southern Africa. Transgressive segregation for a number of traits was observed in the two F2 bi-parental populations, as some individual lines in the segregating populations showed trait values greater or less than their parents. The variability between twelve genotypes and the two F2 bi-parental segregating populations and the negative relationship between plant architectural traits and yield related traits provide resources for development of structured populations and breeding lines for bambara groundnut breeding programme.

scholarly journals Bioethanol Production from Biomass of Selected Sorghum Varieties Cultivated as Main and Second Crop

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6291
Author(s):  
Jolanta Batog ◽  
Jakub Frankowski ◽  
Aleksandra Wawro ◽  
Agnieszka Łacka
Keyword(s):  
Alternative Energy ◽  
Plant Biomass ◽  
Ethanol Yield ◽  
Principal Component ◽  
Temperate Climate ◽  
Chemical Components ◽  
Alternative Energy Sources ◽  
Detailed Statistical Analysis ◽  
Second Year ◽  
And Cluster Analysis

In recent years, there has been a dynamic development of alternative energy sources and the use of plant biomass for the production of bioenergy is one of the possibilities of improving the energy mix. Therefore, it is worth reaching for new, less popular and perspective solutions, which certainly include sorghum, a drought-resistant plant with a high yielding potential and various applications in the bioeconomy. The aim of the research was to determine the amount of bioethanol obtained from the biomass of three sorghum varieties (Rona 1, Santos, Sucrosorgo 506) grown in the main and second crop for three years in the temperate climate typical of Central and Eastern Europe. The yields of sorghum cultivars grown as main and second crops, chemical components of sorghum biomass (cellulose, hemicellulose, lignin) and the amount of ethanol per a ton of dry matter of straw and ethanol yield per hectare were evaluated. The experiments and research carried out show, especially in the second year, that the Sucrosorgo 506 variety can be recommended for the cultivation of biomass and its use for the production of lignocellulosic ethanol is effective, both in main and second crop cultivation. The discussed results were confirmed by detailed statistical analysis, incl. principal component analysis (PCA) and cluster analysis. To sum up, the production of bioethanol from sorghum biomass is possible in temperate climate and it does not compete with the production of food due to the possibility of growing sorghum after rye.

scholarly journals Effect of Biochar and Irrigation on Soybean-Rhizobium Symbiotic Performance and Soil Enzymatic Activity in Field Rhizosphere

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Ma ◽  
Egamberdieva ◽  
Wirth ◽  
Bellingrath-Kimura
Keyword(s):  
Plant Biomass ◽  
N Uptake ◽  
Critical Factor ◽  
Hydrolytic Activity ◽  
N Fertilizer ◽  
Nutrient Concentrations ◽  
Shoot Biomass ◽  
Soil Enzymatic Activity ◽  
Nodule Number ◽  
Soil Variables

Nitrogen (N) in soybean (Glycine max L.) plants derived from biological nitrogen fixation was shown to be a sustainable N resource to substitute for N fertilizer. However, the limited water supply in sandy soil is a critical factor for soybean nodulation and crop growth. This study investigated the potential mechanism of the effect of biochar and irrigation on the soybean-Rhizobium symbiotic performance and soil biological activity in a field trial. In the absence of N fertilizer, 10 t ha−1 of black cherry wood-derived biochar were applied under irrigated and rainfed conditions on an experimental, sandy field site. The plant biomass, plant nutrient concentrations, nodule number, nodule leghemoglobin content, soil enzyme activities, and soil-available nutrients were examined. Our results show that biochar application caused a significant increase in the nodule number by 35% in the irrigated condition. Shoot biomass and soil fluorescein diacetate hydrolytic activity were significantly increased by irrigation in comparison to the rainfed condition. The activity of soil protease reduced significantly, by 8%, with the biochar application in the irrigated condition. Further, a linear correlation analysis and redundancy analysis performed on the plant, nodule, and soil variables suggested that the biochar application may affect soybean N uptake in the sandy field. Nodulation was enhanced with biochar addition, however, the plant N concentration and nodule Lb content remained unaffected.

scholarly journals Investigating South Africa’s Fresh Peach and Nectarine Value Proposition: Measuring Progress on Achieving Sustainable Consumption in Exports

2020 ◽  
Vol 12 (7) ◽  
pp. 2615
Author(s):  
Chiedza Zvirurami Tsvakirai ◽  
Teboho Jeremiah Mosikari
Keyword(s):  
Climate Change ◽  
South African ◽  
Sustainable Development Goals ◽  
Sustainable Consumption ◽  
Principal Component ◽  
The Sustainable Development ◽  
Composite Indices ◽  
Responsible Consumption ◽  
Value Propositions ◽  
Development Goals

The Sustainable Development Goals (SDGs) have shone a spotlight on the importance of adaption to climate change. However, progress in achieving SDG 12 which calls for, “responsible consumption and production” has been stalled by the unavailability of indicators that adequately capture and motivate increased responsible consumption. To fill this gap, this article presents an alternative indicator that makes use of cultivar characteristics and uses South African fresh peach and nectarine exports as a focus area. Principal component analysis is used to extract and summarize the product value propositions identified in composite indices that were constructed by weighting the proportional use of cultivars in exports between 1956 and 2017. The indices acquired from the analysis were found to measure the provisions for sustainable consumption, good-quality fruit and off-peak fruit supply. The study’s results show that progress was found in the provisions for sustainable consumption and this was mainly driven by improvements in cultivars’ climate change adaptability. However, the last two decades have been characterized by years of successive lower readings on this index. Improvements in fruit quality index were found to be attained at the expense of farm enterprise productivity. The study concludes that strategies be developed to encourage the use of cultivars that promote responsible consumption as, if left uninfluenced, market forces will spur unsustainable production.

Species reassignment of Geotrichum bryndzae, Geotrichum phurueaensis, Geotrichum silvicola and Geotrichum vulgare based on phylogenetic analyses and mating compatibility

2012 ◽  
Vol 62 (Pt_12) ◽  
pp. 3072-3080 ◽  
Author(s):  
Marizeth Groenewald ◽  
Teresa Coutinho ◽  
Maudy Th. Smith ◽  
J. P. van der Walt
Keyword(s):  
South African ◽  
Phylogenetic Analyses ◽  
Culture Collection ◽  
Rrna Gene ◽  
Yeast Culture ◽  
Centraalbureau Voor ◽  
Dna Reassociation ◽  
Nucleotide Divergence ◽  
26S Rrna

The present classification of Galactomyces and its anamorph, Geotrichum, is based on various studies that used morphology, ecology, biochemistry, DNA–DNA reassociation comparisons and gene sequencing. In this study, the identities of strains of the Centraalbureau voor Schimmelcultures yeast culture collection, as well as seven strains from South Africa, were examined by analyses of the nucleotide divergence in the internal transcribed spacer regions of the nuclear rRNA gene (nrRNA) operon, the D1/D2 domains of the 26S rRNA gene and partial actin gene sequences as well as compatibility studies. The South African strains were assigned to species in the genus Galactomyces. The phylogenetic analyses and mating studies revealed that Geotrichum silvicola and Geotrichum bryndzae are synonyms of Galactomyces candidus and that Geotrichum vulgare is a synonym of Galactomyces pseudocandidus.

South African Adolescents' Explanations for Juvenile Delinquency

2002 ◽  
Vol 32 (3) ◽  
pp. 1-6 ◽  
Author(s):  
G.A. Tyson ◽  
C.R. Stones
Keyword(s):  
Secondary School ◽  
South African ◽  
Home Environment ◽  
Emotional Adjustment ◽  
Principal Component ◽  
Eastern Cape ◽  
Varimax Rotation ◽  
Juvenile Offending ◽  
Black And White ◽  
The World

Research in other parts of the world suggests that adolescents invoke a multiplicity of causes to explain juvenile offending. The extent to which the different explanations are endorsed appears partly to be a function of cultural and demographic characteristics. The aim of this study was to investigate South African adolescents' explanations for delinquency and to examine cultural differences in these explanations. A total of 554 secondary school pupils from two Eastern Cape high schools rated 39 explanations for juvenile offending on a Likert scale. Principal component analysis and a varimax rotation of the responses identified seven factors - Home Environment, Antisocial Tendency, Influencability, Social Control, Emotional Adjustment, Deprivation and Social Alienation. The results showed that there were large differences between the Black and White learners in terms of the perceived importance of a number of the explanatory causes.

Gyrodactylids (Gyrodactylidae, Monogenea) infecting Oreochromis niloticus niloticus (L.) and O. mossambicus (Peters) (Cichlidae): A pan-global survey

2010 ◽  
Vol 55 (3) ◽  
Author(s):  
Adriana García-Vásquez ◽  
Haakon Hansen ◽  
Kevin Christison ◽  
Miquel Rubio-Godoy ◽  
James Bron ◽  
...  
Keyword(s):  
South African ◽  
Oreochromis Niloticus ◽  
Dominant Species ◽  
Juvenile Fish ◽  
Principal Component ◽  
Oreochromis Mossambicus ◽  
Molecular Data ◽  
Molecular Analyses ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Two Populations

AbstractGyrodactylus infections in intensively-reared populations of Nile tilapia, Oreochromis niloticus niloticus, have been associated world-wide with high mortalities of juvenile fish. In this study, 26 populations of Gyrodactylus parasitising either O. n. niloticus or Mozambique tilapia, Oreochromis mossambicus, were sampled from fourteen countries and compared with type material of Gyrodactylus cichlidarum Paperna, 1968, Gyrodactylus niloticus (syn. of G. cichlidarum) and Gyrodactylus shariffi Cone, Arthur et Bondad-Reantaso, 1995. Representative specimens from each population were bisected, each half being used for morphological and molecular analyses. Principal component analyses (PCA) identified five distinct clusters: (1) a cluster representing G. cichlidarum collected from O. n. niloticus from 13 countries; (2) the G. shariffi paratype; (3) three specimens with pronounced ventral bar processes collected from two populations of Mexican O. n. niloticus (Gyrodactylus sp. 1); (4) four specimens collected from an Ethiopian population nominally identified as O. n. niloticus (Gyrodactylus sp. 2); (5) nine gyrodactylids from South African O. mossambicus (Gyrodactylus sp. 3). Molecular analyses comparing the sequence of the ribosomal transcribed spacer regions (ITS 1 and 2) and the 5.8S gene from the non-hook bearing half of worms representative for each population and for each cluster of parasites, confirmed the presence of G. cichlidarum in most samples analysed. Molecular data also confirmed that the DNA sequence of Gyrodactylus sp. 2 and Gyrodactylus sp. 3 (the morphologically-cryptic group of South African specimens from O. mossambicus) differed from that of G. cichlidarum and therefore represent new species; no sequences were obtained from Gyrodactylus sp. 1. The current study demonstrates that G. cichlidarum is the dominant species infecting O. n. niloticus, being found in 13 of the 15 countries sampled.

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