Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks...Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks. This study was conducted at a station and in seven villages in the Maradi and Tahoua regions. It aimed to test the effectiveness of neem seed biopesticides [Azadirachta indica A. Juss] and sanitized human urine for integrated insect pest management. The cowpea variety UAM09 1055-6 was used for the experiments. The experimental trial was a Fisher block design consisting of five treatments: neem oil, neem seed extract (NSE), hygienized human urine (HHU), chemical pesticide, and a control, replicated five times at the station and twice in farmers’ environments. The study shows that Megalurothrips sjostedti Trybom, Clavigralla tomentosicollis Stål and Maruca vitrata Fabricius are the main insect pests. Plots treated with synthetic pesticides were the least infested by C. tomentosicollis. They were followed by neem seed extract and HHU treatments, which recorded an infestation level of 2.44 and 20.5 times lower than controls at the station and in farming environments. The density of thrips was 1.06 to 32.6 times lower in treated plots compared to controls. The proportion of pods damaged by M. vitrata was 1.95, 2.55, and 2.77 times lower in plots treated with HHU, NSE, and synthetic pesticide, respectively, compared to controls. Grain yields were 1.80 and 2.62 times higher in UHH and NSE treatments compared to control plots, both at the station and in farmers’ environments. A yield increase of 44.58% and 61.92% was noted for these treatments at the station and in farmers’ environments, respectively. These results may promote the dissemination of NSE and HHU biopesticide technologies in rural areas as an alternative method for integrated pest management of cowpeas.展开更多
Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests....Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests. A trial was conducted during the 2020 and 2022 cropping seasons at the INRAN station in the Maradi region. A Fischer experimental design with 6 repetitions was used to compare 4 treatments: synthetic chemical pesticide;the entomopathogenic fungus Beauveria bassiana;aqueous extracts of neem seeds, and control. Observations were carried out every three days. The cowpea pod-sucking bug, pod borer, and thrips were the main insect pests recorded. In terms of effectiveness, the synthetic pesticide was the best treatment. It reduced insect pest densities by 71.35% to 90.40% in 2020 and by 35.11% to 42.13% in 2022. Grain yields varied between treatments. Neem seed extract followed the synthetic pesticide and significantly reduced insect infestations in both years. The synthetic pesticide and neem seed extract resulted in yields 3 to 5 times higher than the control treatment in 2020. By contrast, B. bassiana 115 and neem seed extract produced similar yields in 2022. Therefore, the results of this study showed that B. bassiana 115 and neem seed extract have insecticidal potential and could be used as an ecological alternative for managing cowpea insect pests in the Sahel.展开更多
Targeting of the synthesized polypeptide in the cells is an important research field in modern cell biology. Cowpea trypsin inhibitor (cpti) gene has been modified and a fusion protein gene (sck) was produced by fusin...Targeting of the synthesized polypeptide in the cells is an important research field in modern cell biology. Cowpea trypsin inhibitor (cpti) gene has been modified and a fusion protein gene (sck) was produced by fusing a signal peptide sequence at cpti 5' end and an endoplasm reticulum (ER) retention signal peptide at cpti3' end respectively. The signal peptide can direct the newly synthesized polypeptide into ER, while ER retention signal can make the protein retained in the ER and its derivative protein body. ELISA test indicated that the accumulation level of foreign CpTI protein in sck transgenic tobacco (Nicotiana tabacum L.) was two times higher than cpti transgenic tobaccos and some individuals were four times higher. At the same time, sck transgenic tobacco has a high resistance to Lepidoptera pest due to the increased accumulation level of foreign CpTI protein. The strategy of foreign protein targeting can be used to increase the accumulation level of foreign protein in transgenic plants and can be widely applied to other related research field in plant genetic engineering.展开更多
[Objective] The aim was to study the effects of sound waves with different types and frequency characteristics on the growth of cowpea（Vigna unguiculata）during seedling stage.[Method] The insect-music mixed sound（M...[Objective] The aim was to study the effects of sound waves with different types and frequency characteristics on the growth of cowpea（Vigna unguiculata）during seedling stage.[Method] The insect-music mixed sound（MI）,cuckoo acoustic song,cricket acoustic song,single 400 Hz frequency sound wave,F5 and Fn sound waves composed of different frequencies were designed to investigate their effects on height and weight of cowpea seedling,and experimental data were statistically analyzed and multiple-compared by EXCEL.[Result] After treatment by sound waves with six different types and frequencies,the growth situations of cowpea were better than that in control.This indicated that sound waves could significantly promote height growth of plant.The treatments with good growth-promotion effect included 400 Hz frequency sound wave,cuckoo acoustic song and cricket acoustic song,followed by MI,Fn and F5.Cuckoo and cricket acoustic song treatment could promote the weight of cowpea seedling during seedling stage.[Conclusion] Sound waves with different types and frequency characteristics had significant growth-promotion effect on growth of cowpea during seedling stage,but their effects were different.展开更多
This study aimed to investigate the effects of different precooling treatments（0 ℃ ice water, 4 ℃ cold water and 4 ℃ refrigerator） on the physiological characteristics of post-harvest cowpea. The results showed t...This study aimed to investigate the effects of different precooling treatments（0 ℃ ice water, 4 ℃ cold water and 4 ℃ refrigerator） on the physiological characteristics of post-harvest cowpea. The results showed that precooling treatments could effectively maintain the sensory quality and slow the loss of nutrients of cowpea. Among the treatments, cold water precooling showed the best freshkeeping effect on post-harvest cowpea. It slowed the decline of sensory quality of post-harvest cowpea, inhibited the increase of weight loss rate, ethylene release amount, relative conductivity and malondialdehyde（MDA） content, and the degradation of total soluble solids（TSS）, vitamin C, chlorophyll and soluble protein, and improved the activities of catalase（CAT） and peroxidase（POD）.展开更多
Both non-transgenic hybrid triploid poplars [ (Populus tomentosa×P.bolleana)×P.tomentosa ] and transgenic ones expressing cowpea trypsin inhibitor were cut at the base of the stem to produce auxoblasts, an...Both non-transgenic hybrid triploid poplars [ (Populus tomentosa×P.bolleana)×P.tomentosa ] and transgenic ones expressing cowpea trypsin inhibitor were cut at the base of the stem to produce auxoblasts, and used as source of leaves for insect feeding trials performed on 3 major insect species of poplar, the forest tent caterpillar ( Malacosoma disstria L.), gypsy moth ( Lymantria dispar L.) and willow moth ( Stilpnotia candida Staudinger). The height and basal diameter of trees were measured by the end of that year (2000). The results indicated that the growth elements of transgenic poplars were not interfered by the incorporation of the CpTI gene. Intriguingly, the height and basal diameter of the clone TG04 were much greater than that of the control. The transgenic foliage consumed by insects induced the increase of larval mortality, and decrease of larval wet weight gain, faecal output, pupal weight and egg deposition. Among them 3 transgenic clones, TG04, TG07 and TG71 received special attention for their outstanding insect resistance compared with other transgenic clones, which showed that the CpTI gene in them was expressed more actively and stably than in others.展开更多
In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statisti...In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statistical analysis were conducted to study the control effect of biopesticide chitosan, biochemical compound Prochloraz-Chitosan and chemical pesticides difenoconazole and thifluzamide by field efficacy trials. The results showed that under serious occurrence of anthracnose in autumn greenhouse cowpea, when the 2% chJtosan AS （2 250 g/hm^2）, 46% Prochloraz-Chitosan EW （450 g/hm^2）, 10% difenoconazole WG （900 g/hm^2, CK） or 24% thifluzamide SC （360 ml/hm^2） were applied three times with an interval of 5-8 d, the control efficiency on day 7, 14 and 20 reached 83%, 78% and 73%, respectively. No significant difference was found in control efficiency among the four kinds of agents. These four kinds of agents, especially chitosan and Prochloraz-Chitosan, could be used as ideal agents for controlling anthracnose, as well as for modern agricultural demonstration zones, pollution-free agricultural products, green agricultural products and organic agricultural products,thereby meeting the develop- ment needs of ＇modern agriculture, green agriculture, organic agriculture and ecological agriculture.展开更多
In order to mitigate the occurrence and damage of cowpea whitefly, reduce chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design andstatistical analysi...In order to mitigate the occurrence and damage of cowpea whitefly, reduce chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design andstatistical analysis were used in field efficacy trials, to study the control effect of cowpea anthracnose by usingchemical pesticides dinotefuran, acetamiprid, pymetrozine, and bio-pesticide avermectin. The results showed that after applying 1.85% avermectin EC 375 g, 20% dinotefuran SP 600 g, 5% acetamiprid WP 600 g, and 25% pymetrozine WP 600 g （control pesticide） per hm2 once every 5-8 days, and 3 times continuously underserious autumn occurrence of greenhouse whitefly, the control efficacy was 90.9%, 97.0%, 88.0%, 93.9%respectively on the 7th day after the pesticides application; 97.4%, 92.1%, 84.2%, 89.4% respectively on the 14th day after the pesticides application; and 95.6%, 86.7%, 82.2%, 84.5%, respectively on the 20th day afterthe pesticides application. The control effects among avermectin, acetamiprid and pymetrozine were not significantly different, while the effects of avermectin and pymetrozine were significantly higher than that of acetamiprid on the 7th day. The control effects among avermectin, dinotefuran and pymetrozine were not significantly different, while significantly higher than that of acetamiprid on the 14th day. The control effect of avermectin was significantly higher than that of dinotefuran, acetamiprid and pymetrozine on the 20th day. Meanwhile, the control effect of avermectin was slightly lower, higher and much higher than that of dinotefuran on the 7th, 14th, 20th day respectively after the treatment. These results indicated that the four pesticides,especiaLly biopesticide avermectin, were ideal pesticides, which could not only be used for controlling cowpea whitefly, but also realize modern, green, organic and ecological agricultural production.展开更多
The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crop...The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crops in the local context has not been explored.Thus,an in-depth understanding of climate change in the local context may support the design of locally relevant adaptation responses to current and future climate risks.This study examined the impacts of climate variables(annual rainfall,annual average temperature,rainfall indices(rainfall onset,rainfall cessation,and the length of rainy days),and the number of dry days)on the yields of leguminous crops(groundnuts,cowpeas,and soybeans)in the Guinea Savanna agroecological zone of Ghana during the period of 1989-2020.The data were analysed using Mann-Kendall’s trend,Sen’s slope test,correlation analysis,and Multiple Regression Analysis(MRA).The findings revealed that annual rainfall,annual average temperature,rainfall onset,rainfall cessation,and the length of rainy days,and the number of dry days all showed varied impacts on the yields of groundnuts,cowpeas,and soybeans.The trend analysis detected a marginal decrease in the amount of rainfall,rainfall onset,and the number of dry days from 1989 to 2020(P>0.050).Annual average temperature and the length of rainy days substantially varied(P<0.050)from 1989 to 2020,showing an increasing trend.The findings also showed a marked upward trend for the yields of groundnuts,cowpeas,and soybeans during 2005-2020.The climate variables analysed above increased the yields of groundnuts,cowpeas,and soybeans by 49.0%,55.0%,and 69.0%,respectively.The yields of groundnuts,cowpeas,and soybeans fluctuated with the variability of 30.0%,28.0%,and 27.0%from 2005 to 2020,respectively.The three leguminous crops under study demonstrated unpredictable yields due to the variations of annual rainfall,annual average temperature,rainfall onset,rainfall cessation,the length of rainy days,and the number of dry days,which stressed the need for agricultural diversification,changing planting dates,using improved seed variety,and irrigation to respond to climate change.The results of this study implied that climate change considerably impacts crop production in the Guinea Savanna agroecological zone of Ghana,emphasizing the urgency of locally based and farmer-induced adaptation measures for food security and resilient agricultural systems.展开更多
Information about the type of gene action governing the inheritance of cowpea seed flavonoid content and antioxidant activity is prerequisite for starting an effective breeding program for developing improved varietie...Information about the type of gene action governing the inheritance of cowpea seed flavonoid content and antioxidant activity is prerequisite for starting an effective breeding program for developing improved varieties. For this purpose, half-diallel crosses among seven diverse parents were made. The homozygous parents and 21 F1 hybrids were evaluated at Maroua in the Sudano-Sahelian zone of Cameroon using a randomized complete block design with three replicates. Flour samples produced from decorticated seeds were used for biochemical analysis. Analysis of variance showed significant differences(P < 0.001) among genotypes for the studied traits with ranges of 363.6–453.9 mg rutin equivalent per 100 g dry weight(DW) for total flavonoids, 13.38–30.73 mg ascorbic acid equivalent per 1 g DW for ferric iron reducing activity, 70.98–266.93 mg trolox equivalent per 100 g DW for 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity, and 90.93–370.62 mg trolox equivalent per 100 g DW for 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) free radical scavenging activity. Both additive and non-additive gene effects were significant in the genetic control of these traits, but dominance variance was greater than additive variance. The traits were mainly controlled by overdominance model suggesting a selection in the delayed generations.Broad- and narrow-sense heritability estimates varied from 0.90 to 0.99 and from 0.12 to 0.45,respectively. The variances due to both general and specific combining ability were highly significant for all studied traits. Recessive alleles had positive effects on DPPH and ABTS scavenging activities, whereas dominant alleles had positive effects on flavonoid content and ferric iron reducing activity. These results could help cowpea breeders to improve the antioxidant potential of cowpea seeds by appropriate selection.展开更多
The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in c...The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in cowpea using diallel analysis. For this purpose,half-diallel crosses were made among seven diverse parents. The amount of total soluble sugar was estimated by the phenol sulfuric acid reagent method and reducing sugar were measured by the DNS(3,5-dinitrosalicylic acid) reagent method. The total soluble sugar ranged from 11.12(VYA) to 40.79 mg g^(-1)(IT93 K-693-2) with a mean of 22.31 mg g^(-1).Reducing soluble sugar showed a mean value of 9.11 mg g^(-1) and ranged from 13.61(TVx3236) to 4.98 mg g^(-1)(Lori niebe). Diallel analysis showed that both additive and non-additive gene effects were significant in the genetic control of these traits. However,dominance variance was greater than additive variance for soluble sugar. The traits were controlled mainly by an overdominance model, suggesting the advantage of delaying selection to later generations. Soluble sugar content was found to be highly heritable, with broad-sense heritability ranging from 0.987 to 0.976. Narrow-sense heritability ranged from0.154 to 0.422 and revealed the lower importance of additive variance. Parents and F_1 hybrids differed significantly on the basis of their general and specific combining abilities,respectively. Recessive alleles had positive effects on total soluble sugar and reducing soluble sugar. These results could help cowpea breeders improve the acceptability of cowpea seeds and cowpea-based foods by appropriate selection.展开更多
[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, t...[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, to determine the inhibition rate of extract against enzyme. The influences of different sampiing methods and sampling parts on detection results were compared. [ Results] The positive rate of standard sampling was 18.18% higher than that of non-stand- ard sampling, and the positive rate of samples collected from cowpea tail was 16.67% higher than that collected from other parts. [ Condmions] Enzyme inhibi- tion rate method is suitable for rapid detection of organophosphorus and carbamate pesticides in cowpea.展开更多
Cowpea(Vigna imguicuiata) is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 10...Cowpea(Vigna imguicuiata) is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 100 genomic simple sequence repeat(SSR) markers were developed from cowpea unigene and genome sequences, respectively. Among them, 27 genic and 27 genomic SSR markers were polymorphic and were used for assessment of genetic diversity and population structure in 105 selected cowpea accessions. A total of 155 alleles and 2.9 alleles per marker were identified, and the average polymorphic information content(PIC) value was 0.3615. The average PIC of genomic SSRs(0.3996) was higher than that of genic SSRs(0.3235), and most of the polymorphic genomic SSRs were composed of di-and trinucleotide repeats(51.9% and 37.0% of all loci, respectively). The low level of detected genetic diversity may be attributed to a severe genetic bottleneck that occurred during the cowpea domestication process. The accessions were classified by structure and cluster analysis into four subgroups that correlated well with their geographic origins or collection sites. The classification results were also consistent with the results from principal coordinate analysis and can be used as a guide during future germplasm collection and selection of accessions as breeding materials for cultivar improvement. The newly developed genic and genomic SSR markers described in this study will be valuable genomic resources for the assessment of genetic diversity, population structure, evaluation of germplasm accessions, construction of genetic maps, identification of genes of interest,and application of marker-assisted selection in cowpea breeding programs.展开更多
This study determined the effects of genotype-by-environment(G × E) interaction and stability of yield among elite cowpea(Vigna unguiculata L.) selections derived by gamma irradiation. The study was conducted in ...This study determined the effects of genotype-by-environment(G × E) interaction and stability of yield among elite cowpea(Vigna unguiculata L.) selections derived by gamma irradiation. The study was conducted in Namibia at three selected sites: Bagani, Mannheim,and Omahenene, during 2014/2015 and 2015/2016. Thirty-four newly developed mutant genotypes and three local checks were evaluated using a randomized complete block design with three replications. Grain yield data were analyzed using the additive main effects and multiplicative interaction(AMMI) and the genotype main effect plus genotype-by-environment interaction(GGE) biplot methods. The AMMI and GGE biplot models explained 77.49% and 75.57% of total observed genotypic variation, respectively.Bagani and Omahenene were the environments best discriminating the test genotypes during 2014/2015 and 2015/2016, respectively. Four promising mutant genotypes: G9(Sh L3 P74), G10(Sh R3 P4), G12(Sh R9 P5), and G4(Sh L2 P4), showed wide adaptation and grain yields of 2.83, 2.06, 1.99, and 1.95 t ha^(-1), respectively. The novel mutant lines are useful genetic resources for production or future cowpea breeding programs in Namibia or similar environments.展开更多
Symbiotic and phenotypic characteristics of thirty rhiobial isolates obtained from root nodules of two cowpea （Vigna unguiculata L. Walp） cultivars that grown in different sites of Fezzan （Southern part of Libya） ...Symbiotic and phenotypic characteristics of thirty rhiobial isolates obtained from root nodules of two cowpea （Vigna unguiculata L. Walp） cultivars that grown in different sites of Fezzan （Southern part of Libya） were studied. Cultural characteristics and cross-nodulation with Arachis hypogega and Faidherbia albida showed that they were slow-growing rhizobia. Each isolate was found to coexist with non-symbiotic bacteria similar in their cultural characteristics to fast-growing rhizobia. All isolates formed symbiosis with the test plants, but different in their nitrogen-fixation efficiency. Numerical analysis of phenotypic characteristics showed that at boundary level of 70% average similarity, the isolates formed four distinguished groups and two isolates remained separate. Most isolates exhibited wide tolerance to acidity, alkalinity and extreme temperatures. They also resistant to some heavy metals such as mercury, copper, zinc, lead, cadmium and aluminum at low concentrations and antibiotics like polymyxin, colistin, bacitracin and nalidixic acid. Isolates displayed different response to salinity ranging from sensitive, which unable to grow in 1% NaCI to resistant and grow at 2% NaCl or above. Urea was hydrolyzed by most of them and carbohydrates utilizations were different. Sucrose and maltose were metabolized by most of the test isolates, whereas, monosaccharide and sugar alcohols were poorly utilized.展开更多
An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple ...An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple between 1995 and 1996. Four light intensities with nominal values of light transmission namely L0 = 100%, L 1 = 75%, L2 = 50%, L3 = 25% were provided by nylon netting materials which filtered sunlight to varying light percentages. The experiment was a split-plot on randomized complete block design, replicated four times. Growth measurements and yield were recorded at a regular interval in all crops. Leaf morphological characteristics were carried out only on sweet potato. Result on the leaf morphological characteristics showed light intensity strongly influenced growth and development of sweet potato. Specific leaf area values in full light were smaller than those in under heavy shade. The light intensity increased the cowpea seed yield significantly （P 〈 0.01） and the interaction between seasons （year） x light regimes was significant （P 〈 0.01）. In low intensity, pineapple flowered earlier and yielded more than in high intensity. These results have provided useful information in planning intercropping models in coconut based-farming systems in Tanzania.展开更多
Protein sources in the diet of people living in semi-arid land of Kenya are lacking and if available it is costly to them. In terms of safe food and a healthy food supply, cowpeas (Vigna unguiculata.) are a significan...Protein sources in the diet of people living in semi-arid land of Kenya are lacking and if available it is costly to them. In terms of safe food and a healthy food supply, cowpeas (Vigna unguiculata.) are a significant source of protein, carbohydrates, and minerals especially for poor populations in the Kenya, it is said to be poor man’s meat. The aim of this study was to determine nutritional composition of newly bred ten cowpea lines and five varieties commonly grown in Eastern Kenya of Kitui, Machakos and Makueni counties to understand their potential utilization in curbing rising food and nutrition insecurity in arid and semi-arid lands ASALs and in any other food applications in Kenya. The experiment was arranged in Completely Randomized Design (CRD) whereby proximate composition and minerals were determined using standard AOAC and AACC methods and technological characteristics checked using modified methods used by other researchers. Collected data were subjected to Analysis of Variance (ANOVA) using SAS (2006) version 9.1, mean separation was done using Tukey’s Honestly Significant Difference (HSD) method at 5% level of significance. Cowpeas composition ranged from 12.28% - 13.35% for moisture content, 49.37% - 55.74% for total carbohydrates, 2.99% - 3.34% for crude ash, 0.13% - 0.81% for crude lipids, 23.37% - 29.70% for crude protein and 1.40% - 4.34% for crude fibers. Cowpea samples recorded highest percentage of essential amino acids (60.71%) and non-essential amino acids (39.29%). Minerals ranged from 1.97 - 2.69 mg/100g for calcium, 3.23 - 3.90 mg/100g for magnesium, 205.53 - 223.30 mg/100g for sodium, 0.80 - 1.23 mg/100g for zinc, 1071.15 - 1152.62 mg/100g for potassium and 0.62 - 1.06 mg/100g for phosphorus. For technological properties, lines absorbed water equivalent to their weights and they were comparable to varieties grown in the region. From the results it showed that cowpea line IT97K-1042-3, TEXAN PINKIYE, TX123, IT85F-867-5, IT82D-889-1 and IT82D-889 have desirable attributes such as high crude protein contents, good water absorption capacities and volumetric expansion. They compared well with existing K80 variety. These cowpea lines could possibly be bred and combined into a single cowpea line and further improved by breeders to have other good properties such as higher levels of water absorption during soaking hence reduced cooking times. Therefore, this work has shown that cowpea lines developed can be used as food security crop, industrial food applications and enriching foods of low protein like in complementary foods for healthy food supply in Eastern Kenya.展开更多
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...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.展开更多
Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Metho...Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.展开更多
Cowpea viruses are economically important diseases of cowpea in the major growing areas of Uganda and have inflicted negatively on food security, nutrition and income for many households. The objective of the study wa...Cowpea viruses are economically important diseases of cowpea in the major growing areas of Uganda and have inflicted negatively on food security, nutrition and income for many households. The objective of the study was to determine the prevalence and identity of viruses infecting cowpea in the growing districts of Uganda. Surveys were conducted in the field of grown cowpea, and virus symptoms were recorded on the basis of virus incidence and severity in the districts of Apac, Lira, Pader and Kumi. Symptomatic virus leaf samples were also collected from the same fields surveyed for serological test for detection of virus types using antibodies to cowpea aphid-borne mosaic virus (CABMV), cowpea mild mottle virus (CPMMV), cowpea severe mosaic virus (CPSMV), cowpea mosaic virus (CPMV), cowpea chlorotic mottle virus (CPCMV), cucumber mosaic virus (CMV) and cowpea chlorotic mosaic virus (CCMV) in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Results showed that there was the highest percentage of incidence and severity in Kumi (85.4% and 13.8%, respectively) with the lowest percentage of incidence and severity observed in Apac (55.9% and 4.7%, respectively). Serological test revealed the presence of CABMV, CPMMV, CPSMV and CMV in the leaf samples as the major virus types in the surveyed districts. However, CPCMV, CPMV and CCMV were not detected in the leaf samples surveyed in the cowpea growing districts. Serological test also revealed that among the virus types detected, single and multiple virus types occurred in the plant samples. The highest single virus type occurring in the plant samples was CPMMV (11.6%) and the lowest was CABMV (1.8%). The virus types namely CMV, CABMV, CPMMV and CPSMV occurred in combinations with proportion of 7.1% in the infected plant samples. Therefore, this information obtained on the virus types provides an opportunity for breeders to develop cowpea variety with multiple resistance genes to control several virus types infecting cowpea.展开更多
文摘Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks. This study was conducted at a station and in seven villages in the Maradi and Tahoua regions. It aimed to test the effectiveness of neem seed biopesticides [Azadirachta indica A. Juss] and sanitized human urine for integrated insect pest management. The cowpea variety UAM09 1055-6 was used for the experiments. The experimental trial was a Fisher block design consisting of five treatments: neem oil, neem seed extract (NSE), hygienized human urine (HHU), chemical pesticide, and a control, replicated five times at the station and twice in farmers’ environments. The study shows that Megalurothrips sjostedti Trybom, Clavigralla tomentosicollis Stål and Maruca vitrata Fabricius are the main insect pests. Plots treated with synthetic pesticides were the least infested by C. tomentosicollis. They were followed by neem seed extract and HHU treatments, which recorded an infestation level of 2.44 and 20.5 times lower than controls at the station and in farming environments. The density of thrips was 1.06 to 32.6 times lower in treated plots compared to controls. The proportion of pods damaged by M. vitrata was 1.95, 2.55, and 2.77 times lower in plots treated with HHU, NSE, and synthetic pesticide, respectively, compared to controls. Grain yields were 1.80 and 2.62 times higher in UHH and NSE treatments compared to control plots, both at the station and in farmers’ environments. A yield increase of 44.58% and 61.92% was noted for these treatments at the station and in farmers’ environments, respectively. These results may promote the dissemination of NSE and HHU biopesticide technologies in rural areas as an alternative method for integrated pest management of cowpeas.
文摘Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests. A trial was conducted during the 2020 and 2022 cropping seasons at the INRAN station in the Maradi region. A Fischer experimental design with 6 repetitions was used to compare 4 treatments: synthetic chemical pesticide;the entomopathogenic fungus Beauveria bassiana;aqueous extracts of neem seeds, and control. Observations were carried out every three days. The cowpea pod-sucking bug, pod borer, and thrips were the main insect pests recorded. In terms of effectiveness, the synthetic pesticide was the best treatment. It reduced insect pest densities by 71.35% to 90.40% in 2020 and by 35.11% to 42.13% in 2022. Grain yields varied between treatments. Neem seed extract followed the synthetic pesticide and significantly reduced insect infestations in both years. The synthetic pesticide and neem seed extract resulted in yields 3 to 5 times higher than the control treatment in 2020. By contrast, B. bassiana 115 and neem seed extract produced similar yields in 2022. Therefore, the results of this study showed that B. bassiana 115 and neem seed extract have insecticidal potential and could be used as an ecological alternative for managing cowpea insect pests in the Sahel.
文摘Targeting of the synthesized polypeptide in the cells is an important research field in modern cell biology. Cowpea trypsin inhibitor (cpti) gene has been modified and a fusion protein gene (sck) was produced by fusing a signal peptide sequence at cpti 5' end and an endoplasm reticulum (ER) retention signal peptide at cpti3' end respectively. The signal peptide can direct the newly synthesized polypeptide into ER, while ER retention signal can make the protein retained in the ER and its derivative protein body. ELISA test indicated that the accumulation level of foreign CpTI protein in sck transgenic tobacco (Nicotiana tabacum L.) was two times higher than cpti transgenic tobaccos and some individuals were four times higher. At the same time, sck transgenic tobacco has a high resistance to Lepidoptera pest due to the increased accumulation level of foreign CpTI protein. The strategy of foreign protein targeting can be used to increase the accumulation level of foreign protein in transgenic plants and can be widely applied to other related research field in plant genetic engineering.
基金Supported by Major Scientific and Technological Special Projects in Zhejiang Province(2008C12056)~~
文摘[Objective] The aim was to study the effects of sound waves with different types and frequency characteristics on the growth of cowpea（Vigna unguiculata）during seedling stage.[Method] The insect-music mixed sound（MI）,cuckoo acoustic song,cricket acoustic song,single 400 Hz frequency sound wave,F5 and Fn sound waves composed of different frequencies were designed to investigate their effects on height and weight of cowpea seedling,and experimental data were statistically analyzed and multiple-compared by EXCEL.[Result] After treatment by sound waves with six different types and frequencies,the growth situations of cowpea were better than that in control.This indicated that sound waves could significantly promote height growth of plant.The treatments with good growth-promotion effect included 400 Hz frequency sound wave,cuckoo acoustic song and cricket acoustic song,followed by MI,Fn and F5.Cuckoo and cricket acoustic song treatment could promote the weight of cowpea seedling during seedling stage.[Conclusion] Sound waves with different types and frequency characteristics had significant growth-promotion effect on growth of cowpea during seedling stage,but their effects were different.
基金Supported by National Staple Vegetable Industrial Technology System(CARS-25)Research and Demonstration Project for Horticultural Crop Eco-efficient Production Technology in Non-arable Lands in Northwest China(201203095)Youth Foundation of Beijing Academy of Agriculture and Forestry Sciences(201404)~~
文摘This study aimed to investigate the effects of different precooling treatments（0 ℃ ice water, 4 ℃ cold water and 4 ℃ refrigerator） on the physiological characteristics of post-harvest cowpea. The results showed that precooling treatments could effectively maintain the sensory quality and slow the loss of nutrients of cowpea. Among the treatments, cold water precooling showed the best freshkeeping effect on post-harvest cowpea. It slowed the decline of sensory quality of post-harvest cowpea, inhibited the increase of weight loss rate, ethylene release amount, relative conductivity and malondialdehyde（MDA） content, and the degradation of total soluble solids（TSS）, vitamin C, chlorophyll and soluble protein, and improved the activities of catalase（CAT） and peroxidase（POD）.
文摘Both non-transgenic hybrid triploid poplars [ (Populus tomentosa×P.bolleana)×P.tomentosa ] and transgenic ones expressing cowpea trypsin inhibitor were cut at the base of the stem to produce auxoblasts, and used as source of leaves for insect feeding trials performed on 3 major insect species of poplar, the forest tent caterpillar ( Malacosoma disstria L.), gypsy moth ( Lymantria dispar L.) and willow moth ( Stilpnotia candida Staudinger). The height and basal diameter of trees were measured by the end of that year (2000). The results indicated that the growth elements of transgenic poplars were not interfered by the incorporation of the CpTI gene. Intriguingly, the height and basal diameter of the clone TG04 were much greater than that of the control. The transgenic foliage consumed by insects induced the increase of larval mortality, and decrease of larval wet weight gain, faecal output, pupal weight and egg deposition. Among them 3 transgenic clones, TG04, TG07 and TG71 received special attention for their outstanding insect resistance compared with other transgenic clones, which showed that the CpTI gene in them was expressed more actively and stably than in others.
基金Supported by Circular of the Ministry of Agriculture on Approval of the First Batch of the National Demonstration Zones for Modern Agriculture(NJF[2010]22)Fundamental Research Funds for the Central Universities(XDJK2015C057,SWU114046)~~
文摘In order to mitigate the occurrence and damage of cowpea anthracnose and reduce the chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design and statistical analysis were conducted to study the control effect of biopesticide chitosan, biochemical compound Prochloraz-Chitosan and chemical pesticides difenoconazole and thifluzamide by field efficacy trials. The results showed that under serious occurrence of anthracnose in autumn greenhouse cowpea, when the 2% chJtosan AS （2 250 g/hm^2）, 46% Prochloraz-Chitosan EW （450 g/hm^2）, 10% difenoconazole WG （900 g/hm^2, CK） or 24% thifluzamide SC （360 ml/hm^2） were applied three times with an interval of 5-8 d, the control efficiency on day 7, 14 and 20 reached 83%, 78% and 73%, respectively. No significant difference was found in control efficiency among the four kinds of agents. These four kinds of agents, especially chitosan and Prochloraz-Chitosan, could be used as ideal agents for controlling anthracnose, as well as for modern agricultural demonstration zones, pollution-free agricultural products, green agricultural products and organic agricultural products,thereby meeting the develop- ment needs of ＇modern agriculture, green agriculture, organic agriculture and ecological agriculture.
基金Supported by Approving on the First Batch of National Modern Agriculture Demonstration District by Ministry of Agriculture([2010]No.22)Fundamental Research Funds for the Central Universities(XDJK2016A020)~~
文摘In order to mitigate the occurrence and damage of cowpea whitefly, reduce chemical pesticide consumption, residue and environmental pollution, the methods of forecasting, randomized block design andstatistical analysis were used in field efficacy trials, to study the control effect of cowpea anthracnose by usingchemical pesticides dinotefuran, acetamiprid, pymetrozine, and bio-pesticide avermectin. The results showed that after applying 1.85% avermectin EC 375 g, 20% dinotefuran SP 600 g, 5% acetamiprid WP 600 g, and 25% pymetrozine WP 600 g （control pesticide） per hm2 once every 5-8 days, and 3 times continuously underserious autumn occurrence of greenhouse whitefly, the control efficacy was 90.9%, 97.0%, 88.0%, 93.9%respectively on the 7th day after the pesticides application; 97.4%, 92.1%, 84.2%, 89.4% respectively on the 14th day after the pesticides application; and 95.6%, 86.7%, 82.2%, 84.5%, respectively on the 20th day afterthe pesticides application. The control effects among avermectin, acetamiprid and pymetrozine were not significantly different, while the effects of avermectin and pymetrozine were significantly higher than that of acetamiprid on the 7th day. The control effects among avermectin, dinotefuran and pymetrozine were not significantly different, while significantly higher than that of acetamiprid on the 14th day. The control effect of avermectin was significantly higher than that of dinotefuran, acetamiprid and pymetrozine on the 20th day. Meanwhile, the control effect of avermectin was slightly lower, higher and much higher than that of dinotefuran on the 7th, 14th, 20th day respectively after the treatment. These results indicated that the four pesticides,especiaLly biopesticide avermectin, were ideal pesticides, which could not only be used for controlling cowpea whitefly, but also realize modern, green, organic and ecological agricultural production.
文摘The impacts of climate change on crop yields are receiving renewed interest,with focus on cereals and staple crops at the regional and national scales.Yet,the impacts of climate change on the yields of leguminous crops in the local context has not been explored.Thus,an in-depth understanding of climate change in the local context may support the design of locally relevant adaptation responses to current and future climate risks.This study examined the impacts of climate variables(annual rainfall,annual average temperature,rainfall indices(rainfall onset,rainfall cessation,and the length of rainy days),and the number of dry days)on the yields of leguminous crops(groundnuts,cowpeas,and soybeans)in the Guinea Savanna agroecological zone of Ghana during the period of 1989-2020.The data were analysed using Mann-Kendall’s trend,Sen’s slope test,correlation analysis,and Multiple Regression Analysis(MRA).The findings revealed that annual rainfall,annual average temperature,rainfall onset,rainfall cessation,and the length of rainy days,and the number of dry days all showed varied impacts on the yields of groundnuts,cowpeas,and soybeans.The trend analysis detected a marginal decrease in the amount of rainfall,rainfall onset,and the number of dry days from 1989 to 2020(P>0.050).Annual average temperature and the length of rainy days substantially varied(P<0.050)from 1989 to 2020,showing an increasing trend.The findings also showed a marked upward trend for the yields of groundnuts,cowpeas,and soybeans during 2005-2020.The climate variables analysed above increased the yields of groundnuts,cowpeas,and soybeans by 49.0%,55.0%,and 69.0%,respectively.The yields of groundnuts,cowpeas,and soybeans fluctuated with the variability of 30.0%,28.0%,and 27.0%from 2005 to 2020,respectively.The three leguminous crops under study demonstrated unpredictable yields due to the variations of annual rainfall,annual average temperature,rainfall onset,rainfall cessation,the length of rainy days,and the number of dry days,which stressed the need for agricultural diversification,changing planting dates,using improved seed variety,and irrigation to respond to climate change.The results of this study implied that climate change considerably impacts crop production in the Guinea Savanna agroecological zone of Ghana,emphasizing the urgency of locally based and farmer-induced adaptation measures for food security and resilient agricultural systems.
基金supported in part by funds from the International Foundation for Science (IFS) (agreement number C/5262-1)
文摘Information about the type of gene action governing the inheritance of cowpea seed flavonoid content and antioxidant activity is prerequisite for starting an effective breeding program for developing improved varieties. For this purpose, half-diallel crosses among seven diverse parents were made. The homozygous parents and 21 F1 hybrids were evaluated at Maroua in the Sudano-Sahelian zone of Cameroon using a randomized complete block design with three replicates. Flour samples produced from decorticated seeds were used for biochemical analysis. Analysis of variance showed significant differences(P < 0.001) among genotypes for the studied traits with ranges of 363.6–453.9 mg rutin equivalent per 100 g dry weight(DW) for total flavonoids, 13.38–30.73 mg ascorbic acid equivalent per 1 g DW for ferric iron reducing activity, 70.98–266.93 mg trolox equivalent per 100 g DW for 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity, and 90.93–370.62 mg trolox equivalent per 100 g DW for 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) free radical scavenging activity. Both additive and non-additive gene effects were significant in the genetic control of these traits, but dominance variance was greater than additive variance. The traits were mainly controlled by overdominance model suggesting a selection in the delayed generations.Broad- and narrow-sense heritability estimates varied from 0.90 to 0.99 and from 0.12 to 0.45,respectively. The variances due to both general and specific combining ability were highly significant for all studied traits. Recessive alleles had positive effects on DPPH and ABTS scavenging activities, whereas dominant alleles had positive effects on flavonoid content and ferric iron reducing activity. These results could help cowpea breeders to improve the antioxidant potential of cowpea seeds by appropriate selection.
基金supported in part by funds from International Foundation for Science(C/5262-1)
文摘The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in cowpea using diallel analysis. For this purpose,half-diallel crosses were made among seven diverse parents. The amount of total soluble sugar was estimated by the phenol sulfuric acid reagent method and reducing sugar were measured by the DNS(3,5-dinitrosalicylic acid) reagent method. The total soluble sugar ranged from 11.12(VYA) to 40.79 mg g^(-1)(IT93 K-693-2) with a mean of 22.31 mg g^(-1).Reducing soluble sugar showed a mean value of 9.11 mg g^(-1) and ranged from 13.61(TVx3236) to 4.98 mg g^(-1)(Lori niebe). Diallel analysis showed that both additive and non-additive gene effects were significant in the genetic control of these traits. However,dominance variance was greater than additive variance for soluble sugar. The traits were controlled mainly by an overdominance model, suggesting the advantage of delaying selection to later generations. Soluble sugar content was found to be highly heritable, with broad-sense heritability ranging from 0.987 to 0.976. Narrow-sense heritability ranged from0.154 to 0.422 and revealed the lower importance of additive variance. Parents and F_1 hybrids differed significantly on the basis of their general and specific combining abilities,respectively. Recessive alleles had positive effects on total soluble sugar and reducing soluble sugar. These results could help cowpea breeders improve the acceptability of cowpea seeds and cowpea-based foods by appropriate selection.
文摘[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, to determine the inhibition rate of extract against enzyme. The influences of different sampiing methods and sampling parts on detection results were compared. [ Results] The positive rate of standard sampling was 18.18% higher than that of non-stand- ard sampling, and the positive rate of samples collected from cowpea tail was 16.67% higher than that collected from other parts. [ Condmions] Enzyme inhibi- tion rate method is suitable for rapid detection of organophosphorus and carbamate pesticides in cowpea.
基金funded by the Agricultural Science and Technology Innovation Program (ASTIP) of CAASthe China Agriculture Research System (CARS-09)
文摘Cowpea(Vigna imguicuiata) is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 100 genomic simple sequence repeat(SSR) markers were developed from cowpea unigene and genome sequences, respectively. Among them, 27 genic and 27 genomic SSR markers were polymorphic and were used for assessment of genetic diversity and population structure in 105 selected cowpea accessions. A total of 155 alleles and 2.9 alleles per marker were identified, and the average polymorphic information content(PIC) value was 0.3615. The average PIC of genomic SSRs(0.3996) was higher than that of genic SSRs(0.3235), and most of the polymorphic genomic SSRs were composed of di-and trinucleotide repeats(51.9% and 37.0% of all loci, respectively). The low level of detected genetic diversity may be attributed to a severe genetic bottleneck that occurred during the cowpea domestication process. The accessions were classified by structure and cluster analysis into four subgroups that correlated well with their geographic origins or collection sites. The classification results were also consistent with the results from principal coordinate analysis and can be used as a guide during future germplasm collection and selection of accessions as breeding materials for cultivar improvement. The newly developed genic and genomic SSR markers described in this study will be valuable genomic resources for the assessment of genetic diversity, population structure, evaluation of germplasm accessions, construction of genetic maps, identification of genes of interest,and application of marker-assisted selection in cowpea breeding programs.
基金supported by funds from the International Atomic Energy Agency (IAEA) through the TC Project (NAM5012): Developing High Yielding and Drought Tolerant Crops through Mutation Breeding) and the Ministry of Agriculture, Water and Forestry of Namibia
文摘This study determined the effects of genotype-by-environment(G × E) interaction and stability of yield among elite cowpea(Vigna unguiculata L.) selections derived by gamma irradiation. The study was conducted in Namibia at three selected sites: Bagani, Mannheim,and Omahenene, during 2014/2015 and 2015/2016. Thirty-four newly developed mutant genotypes and three local checks were evaluated using a randomized complete block design with three replications. Grain yield data were analyzed using the additive main effects and multiplicative interaction(AMMI) and the genotype main effect plus genotype-by-environment interaction(GGE) biplot methods. The AMMI and GGE biplot models explained 77.49% and 75.57% of total observed genotypic variation, respectively.Bagani and Omahenene were the environments best discriminating the test genotypes during 2014/2015 and 2015/2016, respectively. Four promising mutant genotypes: G9(Sh L3 P74), G10(Sh R3 P4), G12(Sh R9 P5), and G4(Sh L2 P4), showed wide adaptation and grain yields of 2.83, 2.06, 1.99, and 1.95 t ha^(-1), respectively. The novel mutant lines are useful genetic resources for production or future cowpea breeding programs in Namibia or similar environments.
文摘Symbiotic and phenotypic characteristics of thirty rhiobial isolates obtained from root nodules of two cowpea （Vigna unguiculata L. Walp） cultivars that grown in different sites of Fezzan （Southern part of Libya） were studied. Cultural characteristics and cross-nodulation with Arachis hypogega and Faidherbia albida showed that they were slow-growing rhizobia. Each isolate was found to coexist with non-symbiotic bacteria similar in their cultural characteristics to fast-growing rhizobia. All isolates formed symbiosis with the test plants, but different in their nitrogen-fixation efficiency. Numerical analysis of phenotypic characteristics showed that at boundary level of 70% average similarity, the isolates formed four distinguished groups and two isolates remained separate. Most isolates exhibited wide tolerance to acidity, alkalinity and extreme temperatures. They also resistant to some heavy metals such as mercury, copper, zinc, lead, cadmium and aluminum at low concentrations and antibiotics like polymyxin, colistin, bacitracin and nalidixic acid. Isolates displayed different response to salinity ranging from sensitive, which unable to grow in 1% NaCI to resistant and grow at 2% NaCl or above. Urea was hydrolyzed by most of them and carbohydrates utilizations were different. Sucrose and maltose were metabolized by most of the test isolates, whereas, monosaccharide and sugar alcohols were poorly utilized.
文摘An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple between 1995 and 1996. Four light intensities with nominal values of light transmission namely L0 = 100%, L 1 = 75%, L2 = 50%, L3 = 25% were provided by nylon netting materials which filtered sunlight to varying light percentages. The experiment was a split-plot on randomized complete block design, replicated four times. Growth measurements and yield were recorded at a regular interval in all crops. Leaf morphological characteristics were carried out only on sweet potato. Result on the leaf morphological characteristics showed light intensity strongly influenced growth and development of sweet potato. Specific leaf area values in full light were smaller than those in under heavy shade. The light intensity increased the cowpea seed yield significantly （P 〈 0.01） and the interaction between seasons （year） x light regimes was significant （P 〈 0.01）. In low intensity, pineapple flowered earlier and yielded more than in high intensity. These results have provided useful information in planning intercropping models in coconut based-farming systems in Tanzania.
文摘Protein sources in the diet of people living in semi-arid land of Kenya are lacking and if available it is costly to them. In terms of safe food and a healthy food supply, cowpeas (Vigna unguiculata.) are a significant source of protein, carbohydrates, and minerals especially for poor populations in the Kenya, it is said to be poor man’s meat. The aim of this study was to determine nutritional composition of newly bred ten cowpea lines and five varieties commonly grown in Eastern Kenya of Kitui, Machakos and Makueni counties to understand their potential utilization in curbing rising food and nutrition insecurity in arid and semi-arid lands ASALs and in any other food applications in Kenya. The experiment was arranged in Completely Randomized Design (CRD) whereby proximate composition and minerals were determined using standard AOAC and AACC methods and technological characteristics checked using modified methods used by other researchers. Collected data were subjected to Analysis of Variance (ANOVA) using SAS (2006) version 9.1, mean separation was done using Tukey’s Honestly Significant Difference (HSD) method at 5% level of significance. Cowpeas composition ranged from 12.28% - 13.35% for moisture content, 49.37% - 55.74% for total carbohydrates, 2.99% - 3.34% for crude ash, 0.13% - 0.81% for crude lipids, 23.37% - 29.70% for crude protein and 1.40% - 4.34% for crude fibers. Cowpea samples recorded highest percentage of essential amino acids (60.71%) and non-essential amino acids (39.29%). Minerals ranged from 1.97 - 2.69 mg/100g for calcium, 3.23 - 3.90 mg/100g for magnesium, 205.53 - 223.30 mg/100g for sodium, 0.80 - 1.23 mg/100g for zinc, 1071.15 - 1152.62 mg/100g for potassium and 0.62 - 1.06 mg/100g for phosphorus. For technological properties, lines absorbed water equivalent to their weights and they were comparable to varieties grown in the region. From the results it showed that cowpea line IT97K-1042-3, TEXAN PINKIYE, TX123, IT85F-867-5, IT82D-889-1 and IT82D-889 have desirable attributes such as high crude protein contents, good water absorption capacities and volumetric expansion. They compared well with existing K80 variety. These cowpea lines could possibly be bred and combined into a single cowpea line and further improved by breeders to have other good properties such as higher levels of water absorption during soaking hence reduced cooking times. Therefore, this work has shown that cowpea lines developed can be used as food security crop, industrial food applications and enriching foods of low protein like in complementary foods for healthy food supply in Eastern Kenya.
文摘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.
基金The financial assistance from the Swedish International Development Agency for some of the study (travel grant for Valantine Mbatchou)
文摘Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.
文摘Cowpea viruses are economically important diseases of cowpea in the major growing areas of Uganda and have inflicted negatively on food security, nutrition and income for many households. The objective of the study was to determine the prevalence and identity of viruses infecting cowpea in the growing districts of Uganda. Surveys were conducted in the field of grown cowpea, and virus symptoms were recorded on the basis of virus incidence and severity in the districts of Apac, Lira, Pader and Kumi. Symptomatic virus leaf samples were also collected from the same fields surveyed for serological test for detection of virus types using antibodies to cowpea aphid-borne mosaic virus (CABMV), cowpea mild mottle virus (CPMMV), cowpea severe mosaic virus (CPSMV), cowpea mosaic virus (CPMV), cowpea chlorotic mottle virus (CPCMV), cucumber mosaic virus (CMV) and cowpea chlorotic mosaic virus (CCMV) in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Results showed that there was the highest percentage of incidence and severity in Kumi (85.4% and 13.8%, respectively) with the lowest percentage of incidence and severity observed in Apac (55.9% and 4.7%, respectively). Serological test revealed the presence of CABMV, CPMMV, CPSMV and CMV in the leaf samples as the major virus types in the surveyed districts. However, CPCMV, CPMV and CCMV were not detected in the leaf samples surveyed in the cowpea growing districts. Serological test also revealed that among the virus types detected, single and multiple virus types occurred in the plant samples. The highest single virus type occurring in the plant samples was CPMMV (11.6%) and the lowest was CABMV (1.8%). The virus types namely CMV, CABMV, CPMMV and CPSMV occurred in combinations with proportion of 7.1% in the infected plant samples. Therefore, this information obtained on the virus types provides an opportunity for breeders to develop cowpea variety with multiple resistance genes to control several virus types infecting cowpea.
