Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of...Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.展开更多
Plantain bananas culture encounters the problems of seedlings quantity and quality unavailability. Black Sigatoka Disease (BSD) is one of the main pathological constraints of banana that can severely reduce the photos...Plantain bananas culture encounters the problems of seedlings quantity and quality unavailability. Black Sigatoka Disease (BSD) is one of the main pathological constraints of banana that can severely reduce the photosynthetic leaf area, leading to the losses of production of about 50% in banana plantation. The use of liquid extracts of Tithonia diversifolia could potentially induced the resistance of the PIF seedlings to BSD during the vegetative stages in the nursery. The aim of this work was to evaluate the effect of Tithonia diversifolia liquid extracts against the development of BSD on the PIF plantain bananas seedlings. The explants in the greenhouse and the seedlings in the shade were watered with liquid extracts of T. diversifolia during the process of PIF seedling production in sterile and non-sterile conditions. The treated seedlings show a more effective enhancement of seedlings quality parameters and also induce resistance against BSD. The vegetative stages parameters (the number of shoots, the diameter and the height of shoots, the foliar area, the length and weight roots) were improved in treated seedlings compared to controls ones. The treated seedlings showed maximum protection against BSD of up to 87% compared to controls. They also exhibited an increase in the accumulation of total proteins and total phenolics, as well as the activity of defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). The treatment seems to acts as a vital stimulator and could therefore be a useful tool for small holder farmers favouring an eco-friendly agriculture using fewer synthetic inputs.展开更多
Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species we...Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species weeds growing in its surroundings. The study consisted of two treatments (Tithonia diversifolia infested and Non-Tithonia diversifolia infested soils) and from the two media, the growth of A. hispidium, B. pilosa E. heterophylla, P. maximum and P. polystachion was significantly affected in soil infested by T. diversifolia. The number of weed seedling emergence afore mentioned was significantly lower than what was obtained in soil not infested with T. diversifolia and this accounted for about 38% of the tested weed species. Germination of four of these weeds species (23%) (A. spinosus, C. viscosa, T. procumbens and D. gayana) was enhanced by the presence of T. diversifolia. The study further revealed that weed counts in T. diversifolia infested soil is significantly lower than the ones in soil without T. diversifolia infestation. Likewise, the vegetative growth of some species (A. spinosus, C. viscosa, T. procumbens and D. gayana) was improved in this soil. This shows that T. diversifolia infested soil contains allelochemicals that performed both stimulatory and inhibitory functions.展开更多
Objective:To evaluate the antioxidant activity of extracts of dried flowers of Tithonia diversifolia(Hemsl) A.Gray(T.diversifolia) dry flower-a slirubby plant belonging to the Asteraceac family and very common in Braz...Objective:To evaluate the antioxidant activity of extracts of dried flowers of Tithonia diversifolia(Hemsl) A.Gray(T.diversifolia) dry flower-a slirubby plant belonging to the Asteraceac family and very common in Brazil,providing data to help prevent premature aging skin.Methods:The tests of phytochemical screening included total phenols,tannins,flavonoids,alkaloids and saponins.The active antioxidant was determined by 2,2-diphenyl-1-picrylhydrazyl method.Results:The phytoehemical screening of T.diversifolia dry flowers revealed the presence of phenolic compounds(tannins,flavonoids and total phenolsi,while alkaloids and saponins were not detected.The IC_(50) values showed a strong antioxidant activity of the plant extracts.Conclusions:Therefore,this study suggests the possibility of using dry flowers extracts of T.diversifolia for the prevention of cell aging,as was shown to have significant antioxidant activity.展开更多
Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline ext...Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline extract was prepared,with NaCl(0.15 M),by constant stirring of the dried and pulverized leaves,followed by volume reduction by lyophilization.The extract was phytochemical characterized using ultra-performance liquid chromatography,and total phenol and flavonoid analysis also was performed.The antioxidant capacity was determined through DPPH*radical,the antimicrobial property was evaluated against standard bacteria and fungi,and the viability assays were performed against mice splenocytes.Results:Fifteen compounds were identified belonging to two main classes terpenoids and phenolics.The extract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid.Moreover,extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule[(3.042±0.019)mg AAE/g and(4.12±0.10)mg AAE/g to saline extract and butylated hydroxytoluene,respectively].The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes,in concentrations lower than 50μg/mL,promoting higher proliferation in these cells.Conclusions:Saline extract from Tithonia diversifolia leaves presents potential antioxidant,antifungal properties and induces immunostimulation in mice splenocytes.展开更多
Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of see...Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of seedlings unavailability in quantity and quality, essential for the creation of new plantations. The advent and popularization of the plantlets from stem bits (PIF) in the 2000s raised hopes for solving this problem. However, after about ten years, the PIF has shown some problems limiting its adoption and should be improved for more efficiency. The amendment of PIF substrate production with Tithonia diversifolia could be an alternative to seedlings’ unavailability. This study aims to evaluate the potential stimulative effect of T. diversifolia mulch on plantain PIF seedlings growth and protection against black Sigatoka disease (BSD)caused by Mycosphaerella fijiensis. The parameters of vegetative growth stages and biomarkers accumulation were assessed in sterilized substrate and non-sterilized substrate conditions. T. diversifolia mulch treatment increases the germination rate, the number of shoots, the height and the diameter of shoots, the leaf area as well as the seedlings roots, but it also protects the seedlings against BSD up to about 81% compared to the control seedlings. It also enhances the accumulation of biomarkers such as proteins, polyphenols content and defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). T. diversifolia mulch seems to act in PIF seedlings production as a vital stimulator. It can therefore be taken as a tool for a more sustainable and resilient agriculture, and for poverty alleviation of poor small holder farmers.展开更多
To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native species.However,few studies have compared the photosynthetic dynamics between...To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native species.However,few studies have compared the photosynthetic dynamics between invasive and native species during light fluctuations.We compared photosynthetic induction,relaxation dynamics and leaf traits between the invasive species,Tithonia diversifolia and two native species,Clerodendrum bungei and Blumea balsamifera,in full-sun and shady habitats.The photosynthetic dynamics and leaf traits differed among species.T.diversifolia showed a slower induction speed and stomatal opening response but had higher average intrinsic water-use efficiency than the two native species in full-sun habitats.Thus,the slow induction response may be attributed to the longer stomatal length in T.diversifolia.Habitat had a significant effect on photosynthetic dynamics in T.diversifolia and B.balsamifera but not in C.bungei.In shady habitat,T.diversifolia had a faster photosynthetic induction response than in full-sun habitat,leading to a higher average stomatal conductance during photosynthetic induction in T.diversifolia than in the two native species.In contrast,B.balsamifera had a larger stomatal length and slower photosynthetic induction and relaxation response in shady habitat than in full-sun habitat,resulting in higher carbon gain during photosynthetic relaxation.Nevertheless,in both habitats,T.diversifolia had an overall higher carbon gain during light fluctuations than the two native species.Our results indicated that T.diversifolia can adopt more effective response strategies under fluctuating light environments to maximize carbon gain,which may contribute to its successful invasion.展开更多
Many views, paradigms and concepts have been advocated in recent decades on soil fertility and soil conservation across the globe in order to provide sustainable solutions to the rising food and nutrition insecurity w...Many views, paradigms and concepts have been advocated in recent decades on soil fertility and soil conservation across the globe in order to provide sustainable solutions to the rising food and nutrition insecurity while preserving the natural resource base. Meanwhile, food and nutrition security in Sub-Saharan Africa (SSA) is mainly achieved through smallholder farming systems that are characterized by poor and declining soil fertility, which often leads to low crop yields and low income. Hence, a field trial was established to evaluate the impact of integrated soil fertility management (ISFM) practices on tomato yield and the farm-scale income in smallholder farming systems. The ISFM trial comprised a control with no input, mineral fertilizer, and organic treatments comprising sole Mucuna and Tithonia biomasses as well as their combination (Mucuna + Tithonia). Generally, tomato performance was better with organic plant biomass amendments, with significantly higher (P Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer compared to the control. Meanwhile in comparison to the control, Mucuna + Tithonia and sole Tithonia recorded 3.5 and 3.4 t ha-1 more yield, respectively, which was about twice the additional yield for sole Mucuna and mineral fertilizer with 1.8 and 1.5 t ha-1, respectively (Tukey’s HSD, P Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer, as compared to the control (Tukey’s HSD, P P P Mucuna + Tithonia biomass materials or their sole applications as basal mulch to improve tomato production. Thus, these organic amendments could be an alternative and sustainable integrated soil fertility management strategy to boost tomato production and farm-scale income without jeopardizing the sustainability of the environment. However, this requires more efforts to adapt the different ISFM techniques to the specific needs of smallholder farmers, coupled with effective dissemination strategies that facilitate knowledge transfer and technology adoption.展开更多
The efficacy of the flower, leaf, stem and root of Tithonia diversifolia as organic fertilizer was comparatively studied with NPK fertilizer in improving the performance of sweet pepper （Capsicum annum） in the green...The efficacy of the flower, leaf, stem and root of Tithonia diversifolia as organic fertilizer was comparatively studied with NPK fertilizer in improving the performance of sweet pepper （Capsicum annum） in the green house of the Department of Plant Science of Ekiti State University, Ado Ekiti, Nigeria. The different parts of Tithonia diversifolia were harvested, separately air dried and pulverized. 100 g each of the Tithonia parts and 10 g of NPK were respectively buried into each pot containing the pepper seedlings at two weeks after transplanting using the side dressing method. The study results showed that the leaf biomass of T. diversifolia was not significantly different from NPK fertilizer in improving the growth and yield of Capsicum annum. The stem and root biomass gave comparative growth and yield figures but higher than those recorded from the flower biomass. The control pots resulted to the lowest performance of capsicum annum. It is indicative in this study that Tithonia diversifolia plants ploughed into the soil at the tender stage before flowering will be useful in soil improvement for pepper production. It also revealed that the leave biomass contains nutrients in the required quantity that compared favourably with NPK for pepper production in the study area.展开更多
<em>Tithonia diversifolia</em> is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of <...<em>Tithonia diversifolia</em> is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of <em>Tithonia diversifolia</em> in the production of plantain vivoplants is a great opportunity for small holders’ farmers that cannot easily buy chemical inputs for yield improvement. All plant parts are used because of their richness in nutrients, mineral elements and phytochemicals without knowing which part is the most efficient. <em>Tithonia diversifolia</em> used as substrate amendment for plantain vivoplants production in nursery could promote their growth. This study aims to evaluate the effect of <em>T. diversifolia</em> leaves and stems as substrate amendment on plantain vivoplants growth promotion. The vivoplants were produced in substrates amended with <em>T. diversifolia</em> leaves, stems, combination of leaves and stems, and control without amendment. The vegetative growth parameters (number of shoots, height and diameter of shoots, area of shoots leaves) were assessed in sterilized substrate and unsterilized substrate conditions. <em>T. diversifolia</em> leaves and stems treatment increases the number of shoots, the height and the diameter of shoots as well as the area of shoots leaves compared to the control. <em>T. diversifolia</em> stems are the more efficient treatment, followed by the combination of <em>T. diversifolia</em> leaves and stems and finally the <em>T. diversifolia</em> leaves. They act as a biofertilizer promoting thus, the growth of plantain vivoplants in the nursery. All parts of <em>Tithonia diversifolia</em> can therefore be used by poor small holder farmers, as green manure for soil amendment in a green agriculture context.展开更多
Black Sigatoka disease (BSD) is a foliar disease caused by <em>Mycosphaerella fijiensis</em>, responsible of reduction of the photosynthetic area of banana plant and yield at harvest since it has an influe...Black Sigatoka disease (BSD) is a foliar disease caused by <em>Mycosphaerella fijiensis</em>, responsible of reduction of the photosynthetic area of banana plant and yield at harvest since it has an influence on fruit physiology. The control of BSD relies on the use of chemicals which are not affordable for the small holder farmers and increase the cost of production. Moreover, this chemical control is ineffective, negatively impacting the environment and human health, and is at the origin of strain resistance. <em>Tithonia diversifolia</em> is known as rich in many compounds such as mineral elements, defense metabolites, some phytochemicals;and it is increasingly used in agriculture. Recently, the protective effect of <em>Tithonia diversifolia</em> liquid extract against BSD development on plantain vivoplants in the nursery was highlighted. The aim of our study was to evaluate the efficacy of a biopesticide base on <em>Tithonia diversifolia</em> on the BSD development in a plantain field under high disease pressure. The effect of<em> Tithonia diversifolia</em> biopesticide on <em>Mycosphaerella fijiensis</em> mycelial growth<em> in vitro</em> was evaluated. An experimental field at the flowering stage was selected and treated with the biopesticide base on <em>Tithonia diversifolia</em> at three different concentrations: undiluted (100%), diluted at 1/2 (50%) and diluted at 1/4 (25%) for 17 weeks. The disease severity, the number of functional leaves, the youngest spotted leaf (YSL) and the youngest necrotic leaf (YNL) were evaluated in course of time. The biopesticide treatments significantly (P < 0.001) reduce the BSD severity in course of time, but it is more effective for the most diluted concentration (25%). The number of leaves increases in course of time as well as the rank of the YSL and the YNL confirming the efficiency of BSD control. The efficacy of this biopesticide base on <em>Tithonia diversifolia</em> could be a hopeful ecoresponsible solution for the plantain sector in general and in particular for poor small farmers.展开更多
【目的】研究外来入侵杂草肿柄菊Tithonia diversifolia A. Gray和金腰箭Synedrella nodiflora L. Gaertn.在中国的当前适生区和潜在适生区,以及影响肿柄菊和金腰箭分布的主要环境变量,为监测这2种杂草的入侵和掌握其扩散分布规律提供...【目的】研究外来入侵杂草肿柄菊Tithonia diversifolia A. Gray和金腰箭Synedrella nodiflora L. Gaertn.在中国的当前适生区和潜在适生区,以及影响肿柄菊和金腰箭分布的主要环境变量,为监测这2种杂草的入侵和掌握其扩散分布规律提供理论参考。【方法】对物种分布数据进行拟合分析,对环境变量进行相关性分析,使用ENMeval对物种分布数据进行模型优化,将得到的分布数据、环境变量、正则化参数(Regularization multiplier,RM)和特征组合参数(Feature combination multiplier, FC)导入MaxEnt模型进行分布预测,然后用ArcGIS软件绘制当前及潜在分布适生区。【结果】温度季节变化标准差、最冷季度平均温度是影响肿柄菊分布的主要环境变量,贡献率之和为70.8%;年均温度变化范围、年均降水量、最湿月降水量是影响金腰箭分布的主要环境变量,贡献率之和达76.7%。这2种植物的中、高适生区位于我国西藏南部、云南、广西、广东、福建、海南和台湾地区。【结论】已成功入侵中国的肿柄菊和金腰箭目前主要分布在中国南部热带亚热带一些区域,预测有向内陆逐步扩张的趋势,今后要加强防范。展开更多
基金Supported by the Institute of Research and Development,Walailak University,Thailand(Grant No.WU55304)
文摘Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions.
文摘Plantain bananas culture encounters the problems of seedlings quantity and quality unavailability. Black Sigatoka Disease (BSD) is one of the main pathological constraints of banana that can severely reduce the photosynthetic leaf area, leading to the losses of production of about 50% in banana plantation. The use of liquid extracts of Tithonia diversifolia could potentially induced the resistance of the PIF seedlings to BSD during the vegetative stages in the nursery. The aim of this work was to evaluate the effect of Tithonia diversifolia liquid extracts against the development of BSD on the PIF plantain bananas seedlings. The explants in the greenhouse and the seedlings in the shade were watered with liquid extracts of T. diversifolia during the process of PIF seedling production in sterile and non-sterile conditions. The treated seedlings show a more effective enhancement of seedlings quality parameters and also induce resistance against BSD. The vegetative stages parameters (the number of shoots, the diameter and the height of shoots, the foliar area, the length and weight roots) were improved in treated seedlings compared to controls ones. The treated seedlings showed maximum protection against BSD of up to 87% compared to controls. They also exhibited an increase in the accumulation of total proteins and total phenolics, as well as the activity of defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). The treatment seems to acts as a vital stimulator and could therefore be a useful tool for small holder farmers favouring an eco-friendly agriculture using fewer synthetic inputs.
文摘Pot experiment was carried out in the screen house, Ladoke Akintola University Technology Ogbomosho, Nigeria to determine the possible impact of Tithonia diversifolia on the growth of thirteen selected weed species weeds growing in its surroundings. The study consisted of two treatments (Tithonia diversifolia infested and Non-Tithonia diversifolia infested soils) and from the two media, the growth of A. hispidium, B. pilosa E. heterophylla, P. maximum and P. polystachion was significantly affected in soil infested by T. diversifolia. The number of weed seedling emergence afore mentioned was significantly lower than what was obtained in soil not infested with T. diversifolia and this accounted for about 38% of the tested weed species. Germination of four of these weeds species (23%) (A. spinosus, C. viscosa, T. procumbens and D. gayana) was enhanced by the presence of T. diversifolia. The study further revealed that weed counts in T. diversifolia infested soil is significantly lower than the ones in soil without T. diversifolia infestation. Likewise, the vegetative growth of some species (A. spinosus, C. viscosa, T. procumbens and D. gayana) was improved in this soil. This shows that T. diversifolia infested soil contains allelochemicals that performed both stimulatory and inhibitory functions.
基金Supported by Pro-Saude Ⅱ,Fundacao do ABC(Grant No.2261/2008)
文摘Objective:To evaluate the antioxidant activity of extracts of dried flowers of Tithonia diversifolia(Hemsl) A.Gray(T.diversifolia) dry flower-a slirubby plant belonging to the Asteraceac family and very common in Brazil,providing data to help prevent premature aging skin.Methods:The tests of phytochemical screening included total phenols,tannins,flavonoids,alkaloids and saponins.The active antioxidant was determined by 2,2-diphenyl-1-picrylhydrazyl method.Results:The phytoehemical screening of T.diversifolia dry flowers revealed the presence of phenolic compounds(tannins,flavonoids and total phenolsi,while alkaloids and saponins were not detected.The IC_(50) values showed a strong antioxidant activity of the plant extracts.Conclusions:Therefore,this study suggests the possibility of using dry flowers extracts of T.diversifolia for the prevention of cell aging,as was shown to have significant antioxidant activity.
文摘Objective:To evaluate antimicrobial and antioxidant properties of saline extract from Tithonia diversifolia leaves by phytochemical bioprospecting,and investigate its safety against animal cells.Methods:The saline extract was prepared,with NaCl(0.15 M),by constant stirring of the dried and pulverized leaves,followed by volume reduction by lyophilization.The extract was phytochemical characterized using ultra-performance liquid chromatography,and total phenol and flavonoid analysis also was performed.The antioxidant capacity was determined through DPPH*radical,the antimicrobial property was evaluated against standard bacteria and fungi,and the viability assays were performed against mice splenocytes.Results:Fifteen compounds were identified belonging to two main classes terpenoids and phenolics.The extract showed 22.185 mg GAE/g of total phenolic compounds and 3.220 mg QE/g of flavonoid.Moreover,extract showed higher antioxidant ability similar to butylated hydroxytoluene a standard molecule[(3.042±0.019)mg AAE/g and(4.12±0.10)mg AAE/g to saline extract and butylated hydroxytoluene,respectively].The antimicrobial assays demonstrated that the extract had a significant antifungal potential against Candida species and could be used with safety against mice splenocytes,in concentrations lower than 50μg/mL,promoting higher proliferation in these cells.Conclusions:Saline extract from Tithonia diversifolia leaves presents potential antioxidant,antifungal properties and induces immunostimulation in mice splenocytes.
文摘Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of seedlings unavailability in quantity and quality, essential for the creation of new plantations. The advent and popularization of the plantlets from stem bits (PIF) in the 2000s raised hopes for solving this problem. However, after about ten years, the PIF has shown some problems limiting its adoption and should be improved for more efficiency. The amendment of PIF substrate production with Tithonia diversifolia could be an alternative to seedlings’ unavailability. This study aims to evaluate the potential stimulative effect of T. diversifolia mulch on plantain PIF seedlings growth and protection against black Sigatoka disease (BSD)caused by Mycosphaerella fijiensis. The parameters of vegetative growth stages and biomarkers accumulation were assessed in sterilized substrate and non-sterilized substrate conditions. T. diversifolia mulch treatment increases the germination rate, the number of shoots, the height and the diameter of shoots, the leaf area as well as the seedlings roots, but it also protects the seedlings against BSD up to about 81% compared to the control seedlings. It also enhances the accumulation of biomarkers such as proteins, polyphenols content and defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). T. diversifolia mulch seems to act in PIF seedlings production as a vital stimulator. It can therefore be taken as a tool for a more sustainable and resilient agriculture, and for poverty alleviation of poor small holder farmers.
基金financially supported by the National Natural Science Foundation of China(Grant number:32071661)。
文摘To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native species.However,few studies have compared the photosynthetic dynamics between invasive and native species during light fluctuations.We compared photosynthetic induction,relaxation dynamics and leaf traits between the invasive species,Tithonia diversifolia and two native species,Clerodendrum bungei and Blumea balsamifera,in full-sun and shady habitats.The photosynthetic dynamics and leaf traits differed among species.T.diversifolia showed a slower induction speed and stomatal opening response but had higher average intrinsic water-use efficiency than the two native species in full-sun habitats.Thus,the slow induction response may be attributed to the longer stomatal length in T.diversifolia.Habitat had a significant effect on photosynthetic dynamics in T.diversifolia and B.balsamifera but not in C.bungei.In shady habitat,T.diversifolia had a faster photosynthetic induction response than in full-sun habitat,leading to a higher average stomatal conductance during photosynthetic induction in T.diversifolia than in the two native species.In contrast,B.balsamifera had a larger stomatal length and slower photosynthetic induction and relaxation response in shady habitat than in full-sun habitat,resulting in higher carbon gain during photosynthetic relaxation.Nevertheless,in both habitats,T.diversifolia had an overall higher carbon gain during light fluctuations than the two native species.Our results indicated that T.diversifolia can adopt more effective response strategies under fluctuating light environments to maximize carbon gain,which may contribute to its successful invasion.
文摘Many views, paradigms and concepts have been advocated in recent decades on soil fertility and soil conservation across the globe in order to provide sustainable solutions to the rising food and nutrition insecurity while preserving the natural resource base. Meanwhile, food and nutrition security in Sub-Saharan Africa (SSA) is mainly achieved through smallholder farming systems that are characterized by poor and declining soil fertility, which often leads to low crop yields and low income. Hence, a field trial was established to evaluate the impact of integrated soil fertility management (ISFM) practices on tomato yield and the farm-scale income in smallholder farming systems. The ISFM trial comprised a control with no input, mineral fertilizer, and organic treatments comprising sole Mucuna and Tithonia biomasses as well as their combination (Mucuna + Tithonia). Generally, tomato performance was better with organic plant biomass amendments, with significantly higher (P Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer compared to the control. Meanwhile in comparison to the control, Mucuna + Tithonia and sole Tithonia recorded 3.5 and 3.4 t ha-1 more yield, respectively, which was about twice the additional yield for sole Mucuna and mineral fertilizer with 1.8 and 1.5 t ha-1, respectively (Tukey’s HSD, P Mucuna + Tithonia and sole Tithonia, followed by sole Mucuna and mineral fertilizer, as compared to the control (Tukey’s HSD, P P P Mucuna + Tithonia biomass materials or their sole applications as basal mulch to improve tomato production. Thus, these organic amendments could be an alternative and sustainable integrated soil fertility management strategy to boost tomato production and farm-scale income without jeopardizing the sustainability of the environment. However, this requires more efforts to adapt the different ISFM techniques to the specific needs of smallholder farmers, coupled with effective dissemination strategies that facilitate knowledge transfer and technology adoption.
文摘The efficacy of the flower, leaf, stem and root of Tithonia diversifolia as organic fertilizer was comparatively studied with NPK fertilizer in improving the performance of sweet pepper （Capsicum annum） in the green house of the Department of Plant Science of Ekiti State University, Ado Ekiti, Nigeria. The different parts of Tithonia diversifolia were harvested, separately air dried and pulverized. 100 g each of the Tithonia parts and 10 g of NPK were respectively buried into each pot containing the pepper seedlings at two weeks after transplanting using the side dressing method. The study results showed that the leaf biomass of T. diversifolia was not significantly different from NPK fertilizer in improving the growth and yield of Capsicum annum. The stem and root biomass gave comparative growth and yield figures but higher than those recorded from the flower biomass. The control pots resulted to the lowest performance of capsicum annum. It is indicative in this study that Tithonia diversifolia plants ploughed into the soil at the tender stage before flowering will be useful in soil improvement for pepper production. It also revealed that the leave biomass contains nutrients in the required quantity that compared favourably with NPK for pepper production in the study area.
文摘<em>Tithonia diversifolia</em> is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of <em>Tithonia diversifolia</em> in the production of plantain vivoplants is a great opportunity for small holders’ farmers that cannot easily buy chemical inputs for yield improvement. All plant parts are used because of their richness in nutrients, mineral elements and phytochemicals without knowing which part is the most efficient. <em>Tithonia diversifolia</em> used as substrate amendment for plantain vivoplants production in nursery could promote their growth. This study aims to evaluate the effect of <em>T. diversifolia</em> leaves and stems as substrate amendment on plantain vivoplants growth promotion. The vivoplants were produced in substrates amended with <em>T. diversifolia</em> leaves, stems, combination of leaves and stems, and control without amendment. The vegetative growth parameters (number of shoots, height and diameter of shoots, area of shoots leaves) were assessed in sterilized substrate and unsterilized substrate conditions. <em>T. diversifolia</em> leaves and stems treatment increases the number of shoots, the height and the diameter of shoots as well as the area of shoots leaves compared to the control. <em>T. diversifolia</em> stems are the more efficient treatment, followed by the combination of <em>T. diversifolia</em> leaves and stems and finally the <em>T. diversifolia</em> leaves. They act as a biofertilizer promoting thus, the growth of plantain vivoplants in the nursery. All parts of <em>Tithonia diversifolia</em> can therefore be used by poor small holder farmers, as green manure for soil amendment in a green agriculture context.
文摘Black Sigatoka disease (BSD) is a foliar disease caused by <em>Mycosphaerella fijiensis</em>, responsible of reduction of the photosynthetic area of banana plant and yield at harvest since it has an influence on fruit physiology. The control of BSD relies on the use of chemicals which are not affordable for the small holder farmers and increase the cost of production. Moreover, this chemical control is ineffective, negatively impacting the environment and human health, and is at the origin of strain resistance. <em>Tithonia diversifolia</em> is known as rich in many compounds such as mineral elements, defense metabolites, some phytochemicals;and it is increasingly used in agriculture. Recently, the protective effect of <em>Tithonia diversifolia</em> liquid extract against BSD development on plantain vivoplants in the nursery was highlighted. The aim of our study was to evaluate the efficacy of a biopesticide base on <em>Tithonia diversifolia</em> on the BSD development in a plantain field under high disease pressure. The effect of<em> Tithonia diversifolia</em> biopesticide on <em>Mycosphaerella fijiensis</em> mycelial growth<em> in vitro</em> was evaluated. An experimental field at the flowering stage was selected and treated with the biopesticide base on <em>Tithonia diversifolia</em> at three different concentrations: undiluted (100%), diluted at 1/2 (50%) and diluted at 1/4 (25%) for 17 weeks. The disease severity, the number of functional leaves, the youngest spotted leaf (YSL) and the youngest necrotic leaf (YNL) were evaluated in course of time. The biopesticide treatments significantly (P < 0.001) reduce the BSD severity in course of time, but it is more effective for the most diluted concentration (25%). The number of leaves increases in course of time as well as the rank of the YSL and the YNL confirming the efficiency of BSD control. The efficacy of this biopesticide base on <em>Tithonia diversifolia</em> could be a hopeful ecoresponsible solution for the plantain sector in general and in particular for poor small farmers.
