Screening for Resistance Mechanisms in Cowpea Genotypes on <i>Alectra vogelii</i>

Parasitic angiosperm Alectra vogelii Benth is a growing problem in Malawi, particularly with current emphasis on legumes. Therefore, two studies were set in order to understand the possible mechanisms of resistance in cowpea genotypes on their reaction to the parasitic weed. In the first experiment, Mkanakaufiti, IT99K-7-21-2-2XIT82E-16, Sudan 1 and IT82E-16 were grown in Alectra infested and non-infested pots. The experiment (2*4 factorial treatment combination) was arranged in an RCBD and replicated eight times. The second experiment, involved Petri-dish techniques where 4 genotype roots were assessed on their ability to stimulate the germination of A. vogelii as a proxy for germination stimulant production. The experiment was arranged in an RCBD and replicated five times. In the first experiment, data was collected on;the number of days to first Alectra emergence, Alectra shoot counts at 6, 8, 10, and 12 weeks after planting (WAP), Alectra attachment at 5 and 12 WAP, Alectra biomass at 12 WAP, cowpea biomass parameters at 5 and 12 WAP, yield and yield components per pot. While in the second experiment, number of germinated Alectra seeds per Petri dishes was recorded. The results indicated that IT82E-16 (33.25 days) and Sudan 1 (34.25 days) were earlier infested whilst late on IT99K-7-21-2-2XIT82E-16 (38 days) which correlated to the number of Alectra attachments. There were significant differences (p = 0.05) in weekly Alectra counts between cowpea varieties from 6 up to 10 WAP. Mkanakaufiti and IT99K-7-21-2-2XIT82E-16 were observed with no and few Alectra shoots infestation respectively which was an indicator of resistance mechanism in the study. Number of pods, grain weight (g) and harvest index per pot were significantly affected by inoculation protocol with lower yield on infested cowpea genotypes. The same trend was observed on cowpea varieties where Mkanakaufiti (21.9 g/pot) shown higher yield followed by IT82E-16 (12.5 g/pot) which is susceptible but with tolerance ability to the parasitic weed. The study has shown that resistance mechanisms can be categorized as no or few Alectra shoots, death of Alectra shoots and late infestation. In the Petri dishes, only 3 WAP grown Mkanakaufiti root media failed to induce the germination of Alectra seeds while the opposite occurred on IT82E-16, Sudan 1 and IT99K-7-21-2-2XIT82E-16. On the contrary, 4 WAP grown root media of the four genotypes stimulated Alectra germination which shed more light on the seed behaviour in the soil. This is worth exploring as more could be known to what causes termination of Alectra shoots on Mkanakaufiti. Still, intensifying resistant genotypes should be a goal in order to reduce Alectra seed banks in the soil, thereby, increasing cowpea yield.

Methanol extract of Tephrosia vogelii leaves potentiates the contractile action of acetylcholine on isolated rabbit jejunum

Objective:To investigate the modulating role of methanol extract of Tephrosia vogelii leaves on acetylcholine(ACh)-induced contraction of isolated rabbit jejunum.Methods: Rabbit jejunum segment was removed and placed in an organ bath containing Tyrode's solution, and its contractions were recorded isometrically.Results: ACh(2.0 × 10-10 g/m L) and the extract(2.0 × 10-4 g/m L) individually increased the frequency of contraction(mean ± SEM) of the isolated smooth muscle tissue by 47.6% ± 9.5% and 77.8% ± 66.5%, respectively. When ACh and the extract were combined, the frequency of contraction of the tissue was increased by 222.2% ± 25.9%, representing a 366.7% increase(P < 0.001) over the effect of ACh alone. Similarly, ACh(2.0 × 10-9 g/m L) and the extract individually increased significantly(P < 0.001) the amplitude of contraction of the tissue by 685.7% ± 61.1% and 455.2% ± 38.1%, respectively. When ACh and the extract were combined, the amplitude of contraction of the tissue rose by 1263.8% ± 69.0%, representing 84.3% increase over the ef ect of ACh alone. Conclusions: The findings demonstrate that methanol extract of Tephrosia vogelii leaves potentiates the contractile ef ect of ACh on intestinal smooth muscle, supporting the traditional claim that the plant is purgative.

Wound healing effect of methanolic leaf extract of Napoleona vogelii(Family:Lecythidaceae) in rats

Objective:To investigate the wound healing properly of Napoleona vogelii leaf extract in folkloric medicine.Methods:Roth sexes of adult albino rats(n=25) were used in this study and another group(n=30) were subjected to acute toxicity test(LD_(50)) of the plant extract.For the LD_(50),three randomized groups of 5 rats were first treated with 10,100,1 000 mg/kg body weight(bw),orally.This w as followed by a second treatment of 1500,3000,and 5 000 mg/kg bw of the leaf extract with continual monitoring of the animals for mortality or non-mortality.Incision wounds(1.3cm) were created on the skin of five groups of 5 rals using surgical blade under anesthesia.The first group was topically treated with petroleum jelly alone,group 2 was topically applied 400 mg/mL w/v of the reference drug,Neobaein,while group 3-5 were topically treated with 5-50 mg/mL w/v of the plant extract,respectively.Results:The percentage yield of the extract was 49.80%w/w dry matter.The phytochemical analysis revealed several bioactive constituents including glycosides,tannins,alkaloids,perpenoids.saponins,steroids,proteins,and carbohydrates.The LD_(50) was beyond our experimental limit and was not determined.Increased concentrations(5,20,and 50mg/mL w/v) of the extract had significant(ANOVA,P<0.05) healing effect on the incision wounds giving rise to 125%-140% while treatmentawith Neobacin resulted in 150% healing effect on the third treatment regimen compared to the control(100%).Conclusions:These data indicate that Napoleona vogelii leaf extract contains potent bioactive compounds containing wound healing activity,substantiating its use as a wound healer in folkloric medicine.

Alectra vogelii: A Threat to Bambara Groundnut Production under Climate Change: A Review Paper

Bambara groundnut (BGN) is a protein-rich pulse with the ability to lead to more climate-resilient agriculture. The objective of this study was to review Alectra vogelii as a potential threat to BGN production as a result of climate change. However, the crop faces biotic and abiotic stresses. Alectra vogelii is a major biotic constraint to BGN production, especially in Africa’s non-fertile semi-arid regions. Alectra vogelii (L.) Benth is a parasitic weed in the Orobanchaceae family that causes major damage by forming haustoria attached to roots to enable absorption of nutrients from the BGN. Alectra vogelii produces a large number of minute seeds that can live in the soil for up to 20 years. Based on the reviewed literature, various control mechanisms for dealing with the harmful effects of Alectra vogelii have been proposed. The aim of this research was to reveal the effect of Alectra vogelii on BGN and possible control strategies. We discuss the different control methods such as cultural and mechanical management procedures, phosphorus fertilizers and resistant host crops, herbicide use, and integrated Alectra vogelii control methods. In adaptive methods, however, new techniques remain important. The life cycle of root parasitic weeds is inextricably linked to that of their host, making it an ideal target for such new control techniques, especially when aimed at the early stages of the host-parasite relationship. This review reveals additional information on the function of parasitic seed, strigolactones and how they can be used in breeding to management parasitic weeds.

Zootechnical, Pharmacological Uses and Chemical Composition of <i>Napoleonaea vogelii</i>Hook &Planch (Lecythidaceae) in West Africa<br/>—A Review

Napoleonaea vogelii, Lecythidaceae family is a tropical evergreen shrub widely distributed in the coastal regions of West African countries including Benin. It is a medicinal plant whose leaves and bark are of great utility in traditional medicine. Despite its importance, it is little used in ethnoveterinary medicine and its pharmacological basis in this field and especially in the treatment of parasitic diseases caused by Haemonchus contortus is very little documented. This review aims to synthesise existing data on the chemical composition, pharmacological and zootechnical usefulness of N. vogelii and to identify the gaps of these works in order to propose research perspectives. Google Scholar database was used to gather the majority of useful information available on N. vogelii. The results showed that of the 23 publications included in the present study, 60.87% dealt distinctly with the pharmacological properties of N. vogelii. These properties include anthelmintic, antidiabetic, wound healing, antimicrobial, antibacterial, anti-inflammatory, antioxidant properties and N. vogelii contains many secondary metabolites including alkaloids, tannins, flavonoids, saponins, glycosides which give it its pharmacological properties. The Correspondence Factor Analysis performed for the variables extracts and chemical compounds showed that the presence of a given chemical compound is not dependent on the type of extract. This work has gathered information on N. vogelii and found that the species has powerful therapeutic potentials but very little use in traditional veterinary medicine. More research is needed on this plant to make available ethnoveterinary pharmacological data to enable proper use in the treatment of animal diseases in general and gastrointestinal parasitosis of small ruminants in particular.

An Insight of Parasitic Weeds in Africa and Scientific Developments:A Review

Parasitic weeds are a major threat to food security in Africa and control measures mostly done by smallholder farmers are not effective in eradicating the parasites.This results in a yield loss up to 100%.Parasitic weeds comprise Alectra vogelii,Striga spp.,Orobanche spp.,Rafflesia spp.,and Phoradendron spp.Parasitic attachment is successful when three necessary conditions have been fulfilled namely the compatible host,suitable environment,and parasitic weed.These species parasite plant species through special attachment features such as modified leaves,suckers,haus­toria,or modified roots.In Africa,the variability of parasitic weeds is largely driven by environmental factors such as temperature,rainfall,soil type,and crop husbandry practices.Warmer temperatures create more hospitable conditions for certain parasitic weeds,and allowing them to spread to new areas.Parasitic weed control is vital for effective crop production and the control strategies can be achieved through integrated weed control method that embraces mechan­ical,cultural,chemical,and biological methods.However,the most effective and crucial method is the cultivation of resistant varieties that provide long-term protection against parasitic weeds.Studies have been done on host-parasite attachment where dodder can send out new roots to infected neighbouring plants and spread their parasitic behaviour.More insight and knowledge should offer new goals for control within the life cycle of the parasitic weeds and their metabolic activities.Lastly,disciplines such as agronomy,plant breeding,nutrition,economics,and IT should play their roles effectively in combating parasitic weeds.

非洲山毛豆种子的物理特征、成分分析与油脂组成的研究

以非洲山毛豆Tephrosia vogeliiHook f.种子为材料,分析其部分物理特征和常量化学成分,并通过气相色谱-质谱(GC-MS)和液相色谱-电喷雾离子源-离子阱质谱技术(LC-MSD-Trap-XCT)测定其油脂的脂肪酸与甘油酯组成,并对油脂进行营养评价。实验结果:种子的长、宽、厚分别为4.63、4.01、1.92 mm,千粒质量为21.52 g,密度为659.8 g/L,自流角为25.89°,静止角为23.15°。各组成的质量分数为:水分及挥发物9.89%,粗脂肪13.33%,粗蛋白38.73%,碳水化合物33.21%(可溶性糖10.54%,淀粉10.76%,粗纤维11.91%),灰分4.84%。山毛豆种子油脂的酸价为2.7 mg/g,过氧化值为1.17 mmol/kg,皂化价为188 mg/g,碘价为每100 g样品吸收I2量为118 g,密度为859.9 g/L,折光系数为1.464 8。油脂各组成的体积分数为:十四酸0.15%,十五酸0.031%,十六酸(棕榈酸)18.68%,十六碳一烯酸0.023%,十七酸0.12%,十八酸(硬脂酸)6.46%,油酸19.26%,亚油酸38.76%,亚麻酸8.38%,二十酸1.90%,二十碳一烯酸0.52%,二十一酸0.12%,二十二酸4.09%,二十三酸0.16%,二十四酸1.35%。不饱和脂肪酸含量66.94%。干燥后的油脂含有各组成的质量分数为:脂肪酸单甘油酯0.132%,脂肪酸双甘油酯0.180%,脂肪酸三甘油酯99.687%。山毛豆种子的脂肪和蛋白质的质量分数较高,其油脂的各项指标均符合中国和其他国家食用大豆油标准(GB/T1535-2003;Codex-Stan 210),且富含人体必需的亚油酸和亚麻酸。

非洲山毛豆和山毛豆资源的研究与利用

对非洲山毛豆和山毛豆资源在环境生态修复与保护、土壤改良、杀虫活性及植物群落稳定性方面的研究与利用进行了概述,分析了非洲山毛豆和山毛豆资源的研究与利用过程中存在的问题,并对其研究与开发应用前景进行了展望.

紫外分光光度法测定非洲山毛豆总黄酮含量及方法评价

非洲山毛豆种子乙醇提取物与Mg-HCl、AlCl3的显色反应,以及提取物的紫外吸收光谱特征,证实非洲山毛豆种子中存在黄酮类化合物。根据提取物在λmax273nm的吸光度,利用紫外分光光度法测定样品的黄酮含量。结果表明：该方法测定出非洲山毛豆种子的黄酮质量比为7.777 mg/g,山毛豆油脂的黄酮质量浓度为17.172 mg/mL,山毛豆提取油脂后残余物的黄酮质量比为6.426 mg/g,加标回收率为99.7%-100.1%,相对标准偏差为0.31%-1.24%。此法简单、快捷、线性范围宽、准确,可以用于测定山毛豆总黄酮的含量。

响应面法优化山毛豆蛋白质提取工艺

通过响应面法优化山毛豆蛋白质碱溶酸沉法提取工艺。结果表明,碱溶酸沉法提取山毛豆蛋白质的优化工艺为碱溶pH=11.0、料液比为1∶36(g/mL)、提取温度40℃、提取时间143 min、酸沉pH=4.0;在此条件下山毛豆蛋白质的提取率为83.42%。

山毛豆油磷酸辅助脱胶工艺条件优化

目的:研究酸种类、酸添加量、加水量、脱胶温度、搅拌时间对山毛豆毛油脱胶率的影响。方法:在单因素试验基础上,利用响应面分析法对山毛豆毛油脱胶工艺进行优化。结果:得到山毛豆酸辅助脱胶最佳工艺条件为磷酸添加量2.47g/kg、加水量4.1%、脱胶温度62℃、搅拌时间45min。该条件下山毛豆毛油脱胶率为92.48%,与模型预测值91.5256%接近,脱胶山毛豆油中磷脂含量为0.095%。结论:磷酸辅助脱胶技术可对山毛豆毛油中的磷脂进行有效脱除。

非洲山毛豆油酸法与酶法脱胶工艺优化

以非洲山毛豆毛油为试验材料,研究了酸法脱胶与酶法脱胶工艺参数对其脱胶效果的影响。在单因素试验基础上,通过正交试验得出柠檬酸辅助脱胶的最佳条件为:柠檬酸添加量3.0 g/kg,脱胶温度70℃,加水量4.5%,脱胶时间30 m in。该条件下磷脂脱除率达93.95%,脱胶油的磷含量为28.91 mg/kg。利用均匀设计法确定了磷脂酶脱胶的最佳工艺参数为:脱胶时间5.5 h,酶添加量0.60 IU/g,脱胶温度57℃,加水量3.7%,pH 4.7。在此条件下脱胶油的磷含量为9.853 6mg/kg。试验证明,采用酶法可有效去除非水化磷脂,达到更好的脱胶效果。

西非灰毛豆中鱼藤素的分析

改进了植物中鱼藤素的HPLC检测方法 ;比较UV吸收光谱发现 ,检测波长设为260nm可以有选择地检测鱼藤素 ,减少鱼藤酮的干扰 ;CHCl3-MeOH(体积比9∶1)溶剂适于提取植物中鱼藤素 ,经C_18柱层析 ,用MeOH -H2O(体积比20∶80)洗脱能有效去除大部分杂质 ,而用MeOH -H2O(体积比85∶15～100∶0)洗脱可收集鱼藤素 ;对西非灰毛豆植株中鱼藤素的含量分析试验结果表明 ,该植物中的鱼藤素主要存在于叶中 ,平均含量为20.0×10-3(w) ,其中又以上部叶和新叶含量最多 ,分别为25.2×10-3 和22.0×10-3(w) ;根和枝条中含量很低 ,尤其是枝条仅含0.65×10 -3(w) ,基本上没有实用价值 ;鱼藤素的杀虫活性不如鱼藤酮 ,但由于其含量高 ,在制作杀虫剂时也不能忽视其作用。

响应面优化超声波提取山毛豆抑菌物质条件研究

考察料液比、提取时间、提取溶剂对超声波法提取山毛豆种子中抑菌物质的影响。在单因素试验基础上,利用响应面分析法对山毛豆抑菌物质的提取工艺进行优化。结果得到山毛豆抑菌活性物质的最佳提取工艺条件为液料比12:1(mL/g)、乙醇体积分数55%、超声波提取52min。该条件下质量分数为20%的山毛豆提取液对金黄色葡萄球菌的抑菌圈直径为20.24mm,与理论最优值20.70mm接近。

非洲山毛豆种子提取物对病原菌的抑制作用研究

以非洲山毛豆种子为研究对象,分别以水、乙醇水溶液为溶剂,从山毛豆中提取活性成分,用管碟法探讨了其对六种供试菌的抑菌作用。实验结果表明,山毛豆水提物对大肠杆菌、金黄色葡萄球菌、沙门氏菌的MIC均为50%;当提取剂为30%乙醇,山毛豆提取物对大肠杆菌、金黄色葡萄球菌的MIC为25%,对沙门氏菌的MIC为50%。其水提物、醇/水提取物对黑曲霉、荔枝炭疽、尖孢镰刀菌的抑制作用不明显,对供试细菌在高浓度下呈现较好的抑菌效果。另外,山毛豆抑菌活性成分抑菌pH范围广而且热稳定性强。

响应面法优化山毛豆抑菌物质提取条件的研究

以山毛豆种子为试验材料,对水浴浸提法提取山毛豆种子中抑菌物质的工艺进行研究,研究温度、提取时间、提取溶剂、提取pH对山毛豆种子中抑菌物质提取效果的影响。在单因素试验基础上,利用响应面分析法(RSM)优化山毛豆抑菌物质的提取条件。得到山毛豆抑菌活性物质的最佳提取工艺条件为:温度64℃,提取时间11 h、体积分数52%乙醇为溶剂,溶剂pH 6。该条件下体积分数为20%的山毛豆提取液对3种供试菌的抑菌圈直径均值为18.34 mm,与理论最优值18.42 mm接近。

植物离体培养物中鱼藤酮的分离与HPLC测定

毛鱼藤（Ｄｅｒｒｉｓ ｅｌｌｉｐｔｉｃａ（Ｒｏｘｂ．） Ｂｅｎｔｈ．）和西非灰毛豆（Ｔｅｐｈｒｏｓｉａ ｖｏｇｅｌｉｉ Ｈｏｏｋ．ｆ．）离体培养物经９：１ＣＨＣｌ３／ＭｅＯＨ溶剂提取，Ｃ－１８柱层析分离后，在室温条件下以６６：３４ＭｅＯＨ／Ｈ２Ｏ或４２：５８ ＣＨ３ＣＮ／Ｈ２Ｏ为流动相，对样品进行反相柱ＨＰＬＣ分析。结果表明，毛鱼藤和西非灰毛豆的愈伤组织均能合成鱼藤酮，但含量相当低，分别为 １７．４ ｕｇ／ｇ，１．８ ｕｇ／ｇ干重。经诱导生根分化的毛鱼藤愈伤组织鱼藤酮含量达１３６．２ ｕｇ／ｇ干重，为愈伤组织含量的７．８倍。西非灰毛豆悬浮培养物的鱼藤酮含量虽比愈伤组织有很大提高，但还不及毛鱼藤愈伤组织含量。结果表明，植物的基因类型在次生代谢上起重要作用，同时离体组织或细胞的分化有助于鱼藤酮的生物合成。

非洲山毛豆种子蛋白质组分分析

以山毛豆种子为原料,对其蛋白质进行分级分离,测定了各组分蛋白含量、等电点和溶解度。结果表明,脱脂山毛豆粉的总蛋白含量为47.11%(m/m)。其中,清蛋白、球蛋白、醇溶蛋白和谷蛋白的相对百分含量分别为64.04%、8.83%、11.06%和14.50%,另外含有1.57%难溶的复合蛋白。清蛋白、球蛋白和醇溶蛋白的等电点为pH4.3、pH5.1和pH4.7,谷蛋白的等电点为3.5～3.8。它们在等电点附近溶解度较小,偏离等电点之后即pH>5或pH<4清蛋白和球蛋白的溶解度增大,而醇溶蛋白和谷蛋白的溶解度增加较小。SDS-PAGE电泳表明,非洲山毛豆种子总蛋白的相对分子量差异较大,在20.1～97.2kDa及小于20.1kDa的均有分布,但其谱带分布不明显。清蛋白谱带变化范围为主要有6条,变化区域集中在20.1～66.4kDa及小于20.1kDa的范围。球蛋白在20.1～66.4kDa大约出现了10条谱带。醇溶蛋白在20.1、29.0、44.3kDa分别有3条明显的谱带。谷蛋白在20.1～97.2kDa大约有10条以上的谱带,说明非洲山毛豆种子总蛋白及各组分蛋白均有不同的分子组成。

非洲山毛豆蛋白质组成及其功能特性研究

以山毛豆种子为原料,研究其蛋白质组成及其功能特性。结果表明,脱脂山毛豆粉的总蛋白质量分数为47.11%,其中清蛋白、球蛋白、醇溶蛋白和谷蛋白的质量分数分别为64.04%、8.83%、11.06%和14.50%,另有1.57%的难溶复合蛋白。清蛋白和谷蛋白在pH4和球蛋白和醇溶蛋白在pH5溶解性、起泡性、乳化性均差,而泡沫稳定性和乳化稳定性较好。各蛋白组分的持水持油性均较好。在>pH5或<pH4的条件下,清蛋白和球蛋白的溶解性、起泡性和乳化性较好,其余蛋白组分相对较差。与大豆蛋白相比,山毛豆主要蛋白清蛋白有较好的溶解度、持水持油性、起泡性、泡沫稳定性、乳化性及乳化稳定性。