In vitro antioxidant and antidiabetic potential of crude extracts from the seed coat and fruit pulp of Strychnos madagascariensis

Please read abstract in the article.The Research Office, University of Zululand, South Africahttps://www.phcogj.comhj2021Biochemistr

The threat of the combined effect of biotic and abiotic stress factors in forestry under a changing climate

Plants encounter several biotic and abiotic stresses, usually in combination. This results in major economic losses in agriculture and forestry every year. Climate change aggravates the adverse effects of combined stresses and increases such losses. Trees suffer even more from the recurrence of biotic and abiotic stress combinations owing to their long lifecycle. Despite the effort to study the damage from individual stress factors, less attention has been given to the effect of the complex interactions between multiple biotic and abiotic stresses. In this review, we assess the importance, impact, and mitigation strategies of climate change driven interactions between biotic and abiotic stresses in forestry. The ecological and economic importance of biotic and abiotic stresses under different combinations is highlighted by their contribution to the decline of the global forest area through their direct and indirect roles in forest loss and to the decline of biodiversity resulting from local extinction of endangered species of trees, emission of biogenic volatile organic compounds, and reduction in the productivity and quality of forest products and services. The abiotic stress factors such as high temperature and drought increase forest disease and insect pest outbreaks, decrease the growth of trees, and cause tree mortality. Reports of massive tree mortality events caused by “hotter droughts” are increasing all over the world, affecting several genera of trees including some of the most important genera in plantation forests, such as Pine, Poplar, and Eucalyptus. While the biotic stress factors such as insect pests, pathogens, and parasitic plants have been reported to be associated with many of these mortality events, a considerable number of the reports have not taken into account the contribution of such biotic factors. The available mitigation strategies also tend to undermine the interactive effect under combined stresses. Thus, this discussion centers on mitigation strategies based on research and innovation, which build on models previously used to curb individual stresses.The South African National Research Foundationhttp://frontiersin.org/Plant_Sciencepm2021BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Interactions of pod-zone pH and Ca concentrations on reproductive growth of groundnut (Arachis hypogaea L.)

Low soil pH and calcium (Ca) deficiency in both the root and pod-zone are important problems for groundnut (Arachis hypogaea L.) production world over on account of the light-textured nature of the soils suitable for its production. An experiment was conducted to examine the interaction of pH and Ca supply in the pod-zone on reproductive growth of groundnut. Attached gynophores were cultured singly in solutions at three pH levels (3.5, 5.0 and 6.5) in factorial combination with three solution Ca concentration levels (500, 1000 and 2000 µM). Generally, low pH had an adverse effect on the reproductive growth of groundnut. Approximately 58% of the gynophores cultured in treatment combinations with pH 3.5 produced normal pods, compared to 94% in combinations with pH 5.0 and 6.5. Both pod mass and seed mass were also severely depressed in treatment combinations with pH 3.5 compared to combinations with pH 5.0 and pH 6.5. Increasing Ca from 500 to 2000 µM Ca at low pH had limited ameliorative effect on pod-set, pod and seed mass whereas positive responses were higher at the intermediate pH of 5.0. A combination of high Ca and pH appeared to be detrimental to pod and seed growth. Pods formed at higher pH and Ca levels generally had dense cover of hairs

Transcriptional reprogramming during recovery from drought stress in Eucalyptus grandis

DATA AND MATERIALS AVAILABILITY : The data sets supporting the results of this manuscript are available on the National Centre for Biotechnology Information (NCBI) repository with the BioProject accession number of PRJNA896601 (https://www.ncbi.nlm.nih.gov/sra/PRJNA896601).The importance of drought as a constraint to agriculture and forestry is increasing with climate change. Genetic improvement of plants’ resilience is one of the mitigation strategies to curb this threat. Although recovery from drought stress is important to long-term drought adaptation and has been considered as an indicator of dehydration tolerance in annual crops, this has not been well explored in forest trees. Thus, we aimed to investigate the physiological and transcriptional changes during drought stress and rewatering in Eucalyptus grandis W. Hill ex Maiden. We set up a greenhouse experiment where we imposed drought stress on 2-year-old seedlings and rewatered the recovery group after 17 days of drought. Our measurement of leaf stomatal conductance (gs) showed that, while gs was reduced by drought stress, it fully recovered after 5 days of rewatering. The RNA-seq analysis from stem samples revealed that genes related to known stress responses such as phytohormone and reactive oxygen species signaling were upregulated, while genes involved in metabolism and growth were downregulated due to drought stress. We observed reprogramming of signal transduction pathways and metabolic processes at 1 day of rewatering, indicating a quick response to rewatering. Our results suggest that recovery from drought stress may entail alterations in the jasmonic acid, salicylic acid, ethylene and brassinosteroid signaling pathways. Using co-expression network analysis, we identified hub genes, including the putative orthologs of ABI1, ABF2, ABF3, HAI2, BAM1, GolS2 and SIP1 during drought and CAT2, G6PD1, ADG1 and FD-1 during recovery. Taken together, by highlighting the molecular processes and identifying key genes, this study gives an overview of the mechanisms underlying the response of E. grandis to drought stress and recovery that trees may face repeatedly throughout their long life cycle. This provides a useful reference to the identification and further investigation of signaling pathways and target genes for future tree improvement.The Technology Innovation Agency, Department of Science and Innovation of South Africa through the Forest Bioeconomy Innovation Cluster Program 1, Woldia University through the Woldia-UP PhD Scholarship Program, and the University of Pretoria Doctoral Research Bursary.https://academic.oup.com/treephys2024-02-26hj2024BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologySDG-15:Life on lan

Some observations on reproductive growth of groundnut (Arachis hypogaea L.) in simplified nutrient solutions

An observation study was conducted to assess if normal and healthy groundnut pods could be produced by attached gynophores cultured in a simple nutrient solution with the aim of using the nutrient solution for detailed studies on nutrient absorption by the reproductive organs of groundnut. Several gynophores of solution grown groundnut plants of a Virginia line Virginia bunch strain 1 (VB-1), Spanish line TMV-3 and Valencia line CBBR4 were cultured in 250 ml vials, each containing an aerated, simplified nutrient solutions consisting of 2 μM iron (Fe) and 0.5 μM zinc (Zn) with or without 100 μM calcium (Ca). In all three cultivars, all gynophores cultured in the nutrient solution containing Ca produced normal and apparently healthy pods and kernels. Pod growth was vigorous in this nutrient solution. In addition, three of CBRR4 gynophores cultured in this solution (in two plants) formed roots from a short distance (apporox. 2.5 cm) above the point of pod attachment that were typical of a tap root system. All three cultivars formed pods in the solution in which no Ca was added, but pod growth was severely restricted, especially in the Virginia line. Symptoms that could be attributable to Ca deficiency developed on all pods formed in the solution without Ca. It was concluded that a simplified solution containing only Ca, Zn and Fe could support groundnut pod growth

Some observations on reproductive growth of groundnut (Arachis hypogaea L.) in simplified nutrient solutions

An observation study was conducted to assess if normal and healthy groundnut pods could be produced by attached gynophores cultured in a simple nutrient solution with the aim of using the nutrient solution for detailed studies on nutrient absorption by the reproductive organs of groundnut. Several gynophores of solution grown groundnut plants of a Virginia line Virginia bunch strain 1 (VB-1), Spanish line TMV-3 and Valencia line CBBR4 were cultured in 250 ml vials, each containing an aerated, simplified nutrient solutions consisting of 2 μM iron (Fe) and 0.5 μM zinc (Zn) with or without 100 μM calcium (Ca). In all three cultivars, all gynophores cultured in the nutrient solution containing Ca produced normal and apparently healthy pods and kernels. Pod growth was vigorous in this nutrient solution. In addition, three of CBRR4 gynophores cultured in this solution (in two plants) formed roots from a short distance (apporox. 2.5 cm) above the point of pod attachment that were typical of a tap root system. All three cultivars formed pods in the solution in which no Ca was added, but pod growth was severely restricted, especially in the Virginia line. Symptoms that could be attributable to Ca deficiency developed on all pods formed in the solution without Ca. It was concluded that a simplified solution containing only Ca, Zn and Fe could support groundnut pod growth

Morphological diversity and fruit production of wild Salacia kraussii (Celastraceae) on the Northern Coast of KwaZulu-Natal, South Africa

This study aimed to assess morphological diversity within Salacia kraussii, a fruit and medicinal wild plant species, based on morphological features and compared the fruit production among morphological types (morphotype) that naturally occur on the northern coast of KwaZulu-Natal. Following one species plant survey, a description of the qualitative morphological features revealed that S. kraussii individuals mainly differed in their leaf shapes, having elliptic, oblong, or obovate leaves. That led us to the identification of three morphotypes, namely Salacia kraussii ‘elliptic’, Salacia kraussii ‘oblong’ and Salacia kraussii ‘obovate’. The analysis of variance (one-way ANOVA) of plant quantitative features indicated that plant height, stem diameter, branch number, leaf number and area, and fruit number were significantly different between plants from different sites (p-values < 0.05) and morphotypes (p-values < 0.01). Generally, S. kraussii grows in KwaZulu-Natal as a suffrutex with many stems and exhibits short plant height, small stem diameter, branches, and little foliage per stem. The average fruit number recorded per plant stem was likewise few. Plants growing in Sikhalasenkosi (site1) dominated in average plant height (35.58 cm), leaf number (45), number of branches (4), and number of fruits (5). Plants with elliptic leaves constantly dominated in average plant height (34.45 cm), foliage (36 leaves of 16.29 cm2 each), number of branches (4), and number of fruits (5). A few plants exhibited a strong vegetative vigor and produced more than 20 fruits. There was a highly positive correlation (CC = 0.8) between plant height and leaf number, branch number and leaf number, and branch number and fruit number. However, a negative correlation (CC = −0.1) was recorded between the leaf area and stem diameter. Overall, the study showed wide morphological diversity and fruit production within and between populations of S. kraussii, on the northern coast of KwaZulu-Natal

Performance of Pleurotus ostreatus mushroom grown on maize stalk residues supplemented with various levels of maize flour and wheat bran

Abstract Improving the performance of mushroom in terms of high production and fast growth rate is essential in mushroom cultivation. In the present study the performance of Pleurotus ostreatus was evaluated using varying levels of wheat bran (WB) and maize flour (MF). The results indicated that Pleurotus ostreatus was highly influenced by different levels of supplementation, with 8% WB, 18% WB and 2% MF having higher contamination rate. The low levels of supplementation gave significantly better mycelial growth rate (MGR) and shorter colonisation period as observed that the control had highest MGR whereby 20% MF had lowest MGR. The pinning time (TP) was shortest at the first flush with minimum of 3 days (12% MF). The higher levels of supplementation showed maximum biological efficiency (BE) such as 14% MF, 12% WB and 14% WB. The yield was also higher at high levels of supplementation such as 20% MF and 8% MF being the exception in the lower levels. Based on the results it was observed that for fast production of oyster mushroom there is no need to supplement the maize stalk substrate but for improved productivity supplements can be added up to certain limits such as 14% MF and 12 WB

Performance of Pleurotus pulmonarius mushroom grown on maize stalk residues supplemented with various levels of maize flour and wheat bran

Abstract The use of supplemented agricultural waste in mushroom cultivation can be one of the environmentally friendly strategies for poverty alleviation. The study evaluated the performance of Pleurotus pulmonarius mushroom grown on maize stalk supplemented with varying levels of wheat bran (WB) and maize flour (MF). A completely random design was used for the experiments. It was observed that Pleurotus pulmonarius was significantly affected by varying levels of supplementation, as 20% WB supplementation encountered higher contamination. The lower supplementation levels gave significantly shorter colonisation period with better mycelial growth rate (MGR). The 2% MF, 2% WB and 4% WB gave significantly higher MGR and faster colonisation. The shortest pinning time (TP) was observed at the first flush with the minimum of 2 days. Higher supplementation levels gave maximum yield and biological efficiency (BE). With further increase of supplementation above a 12% WB and 14% MF, the BE and yield declined. Lower supplementation levels resulted in quicker colonisation period and improved growth rate, whereas high supplementation gave better production in terms of yield and BE. Therefore, for the purpose of maximum production, 12% WB and 14% MF may be recommended while for fast production time, 2% MF and 2% WB are recommended