Cowpea Genotypes Research Articles

Evaluation of cowpea genotypes for resistance to the legume pod borer, Maruca Vitrata (Fabricius) (Lepidoptera: Pyralidae)

16 cowpea varieties were screened for resistance to the legume pod borer, Maruca vitrata F. under natural infestation in the field. Plants were planted in a randomized complete block design in three replicates; each plot consisted of four rows, 3m long. Spacing was 1.5m between plots and 0.75m between rows. Intra- row spacing was 0.2m.Two weeks prior to planting experimental materials, a susceptible cultivar was planted perpendicular to every range of rows within a plot to serve as a reservoir of the test insect, M.vitrata. Plants were sprayed with Monocrotophos at 200g a.i /ha once at the vegetative stage and at the onset of flower bud initiation and later during podding to control other pests apart from Maruca. Larval density, flower damage, pod damage, seed damage, pod load (a measure of the degree of successful pod production) and Index of pod evaluation (Ipe), calculated as [PL X (9-PD)], (a measure of the varietal performance of the cowpea genotypes) were used to assess resistance in cowpea varieties. Significant variations were observed in the level of resistance among the cowpea genotypes in the field. The findings show that Tvu 4578 is resistant while Tvu 1544, IT97K-499-35, IT93K452-1 and IT90K-76 show promising level of resistance. The probable factor contributing to resistance may be non- preference or host plant resistant factors.

Propriedades físicas de grãos de genótipos de feijão-caupi

ABSTRACT The present study aimed to evaluate the physical properties of cowpea genotypes grains. The study was conducted at the Laboratory for Storage and Processing of Grains and Seeds at the North Federal Institute of Minas Gerais (IFNMG) in Januária, MG, Brazil. The treatments were composed of 17 elite lines and 11 cultivars of cowpea. The experimental design was in randomized blocks with four replicates. The properties evaluated were bulk density, angle of repose, 1000-grain weight, shape (sphericity and circularity), size (projected area) of the grains, water content, and porosity of the grain mass. The genotypes give different sizes to cowpea beans, which influences the variation of bulk density, angle of repose, and 1000-grain weight. There was no statistical difference among the cowpea genotypes evaluated for water content and mass porosity.

Evaluation of Cowpea F2 Population for Resistance to Flower Bud Thrips (Megalurothrips sjostedti)

A study to screen F2 populations obtained from IT10K-837-1 x Sanzi for resistance to M. sjostedti. A total of 351 F2 plants were screened under field conditions and each line rated visually for thrips damage score, flower abortion rate, number of pods per plant and number of thrips per flower. The study was conducted during the 2020 cropping seasons where F2 seeds were planted under field conditions. Thrips damage score, flower abortion rate, number of pods per plant, and number of thrips per bloom was all visually scored for each accession. The data from the field and laboratory were analyzed using GENSTAT edition 12 to determine if there were any major variations among the cowpea genotypes. The approximate correlations among all measured parameters, including damage scores at 45 DAP, 55 DAP, 65 DAP, using were established using Breeding View software and heritability values were also calculated. There was a strong and significant correlation between thrips population and damage rating during the planting season. Thrips resistance levels identified in most genotypes in this study are interesting compared to the resistant check Sanzisabinli and can be further exploited for future studies to develop resistant varieties to improve cowpea yields.

Response of cowpea germplasm to bacterial blight in Uganda

Cowpea (Vigna unguiculata (L.) walp) is a legume crop mainly grown on small scale in low–input farming systems in Uganda. Cowpea bacterial blight (CoBB) disease caused by Xanthomonas axonopodis pv. vignicola (Burkh.) Dye is increasingly becoming a major hindrance to cowpea productivity. Sixty-four cowpea genotypes were evaluated for their response to bacterial blight disease (CoBB). Field experiments were carried out during the first and second rainy seasons using alpha lattice design with three replications. Data on disease incidence and severity, grain yield, days to 50% flowering, number of seeds per pod, pod length, number of peduncles per plant, and number of branches per plant were collected. Disease severity and incidence data was used to determine relative Area Under Disease Progress Curve (rAUDPC). Results showed significant differences (P ≤ 0.001) among the genotypes for rAUDPC in each season. The rAUDPC across the seasons indicated that genotypes NE 32, WC 32A, WC 26 and NE 44 with rAUDPC values ranging from 0.22 to 0.26 were resistant to CoBB whereas genotypes NE 31 and NE 40 with rAUDPC values 0.44 and 0.46 respectively were susceptible. The rAUDPC did not show any significant correlation with days to 50% flowering, yield and its components. This study suggested that the genotypes NE 32, WC 32A, NE 44, and WC 26 be used as prospective parents in breeding initiatives to develop bacterial blight-resistant varieties due to their high yields and resistance to CoBB.

Assessment of genetic diversity in cowpea (Vigna unguiculata L.) genotypes by using RAPD markers

The present study was carried out at the department of Plant Biotechnology, College of Agricultural Biotechnology Latur, which aimed to study or assess the genetic diversity in eight different Cowpea genotypes by using the RAPD markers. This is important for cowpea genetic improvement and for the overall management of cowpea germplasm. Eight Cowpea genotypes namely GDVC-2, GC-3, GC-4, GC-6, Gangotri, Pusa Komal, Arka Garima, and VU-5 were assessed by using two RAPD markers (RPI-07 and RPI-08). In RAPD analysis, total of 20 amplicons were generated, among them 19 were polymorphic with 88.8% average polymorphism. RPI-7 and RPI-8 showed 88.8% and 100% polymorphism respectively. The similarity coefficient values ranged from 0.350% to 0.950% indicating high degree of genetic variation. The highest genetic similarity i.e. 0.857% was recorded between Pusa Komal and GC-6 and least genetic similarity i.e. 0.125% was observed in between VU-5 and GC-4. Two screened primers are found to be polymorphic (94.4%) with high polymorphic information content (PIC) which efficiently discriminating the varieties at molecular level.

Combining Ability of Cowpea (Vigna unguiculata (L) Walp) Genotypes for Resistance to Cowpea Bacterial Blight in Uganda

The low productivity of cowpea is partly attributed to a number of constraints including diseases such as cowpea bacterial blight (CoBB). Cowpea bacterial blight has the capacity to cause up to 92% yield loss under severe infections. The objective of this study was to determine the combining ability for resistance to CoBB among cowpea genotypes in Uganda. Nine selected parents were crossed to produce 63 progenies. F1 progenies were evaluated and data gathered included days to 50% flowering, CoBB disease scores and grain yield. The mean squares for rAUDPC due to GCA and SCA effects were significant (P≤0.001) and non-significant respectively. The broad sense coefficient of genetic determination (BCGD) and narrow sense coefficient of genetic determination (NCGD) were 44.3% and 29.1% respectively for rAUDPC. Parents WC 26 (-0.023) and NE 31 (-0.035) had highly significant negative GCA effects for rAUDPC and were therefore good general combiners for this trait. Crosses SECOW 3B x ACC 26 X SECOW 1T and WC 26 x NE 32 had negative significant SCA effect for rAUDPC with a values of -0.073 and -0.06, respectively while Crosses ACC 26 x SECOW 1T x NE 40 (-0.07) and NE 40 x WC 26 (-0.06) had significant negative reciprocal effects for rAUDPC. This study revealed that genetic inheritance for cowpea bacterial blight was controlled predominantly by additive gene effects. Parents WC 26 and NE 31 identified as good general combiners for resistance to CoBB could be utilized as sources of resistance while Crosses SECOW 3B x ACC 26 X SECOW 1T, WC 26 x NE 32, ACC 26 X SECOW 1T x NE 40 and NE 40 x WC 26 that were the best specific combiners for resistance to CoBB could be put under further evaluation as potential varieties.

The impact of climate change on the productivity of cowpea (<em>Vigna unguiculata</em>) under three different socio-economic pathways

Crop models are useful tools for simulating the impact of climate change on crop growth, development and yield. This study assesses the impact of climate change on cowpea yield in soils with low levels of phosphorous content mainly in the Sudan Savanna and Forest Transition Zone of West Africa. A crop model solution within the general modelling framework SIMPLACE in combination with the output of four climate models for 3 contrasting shared socio-economic scenarios (SSP126, SSP370, and SSP585) was used to simulate the impact of climatic change on phenology, above ground biomass and yield parameters of cowpea. The simulations were carried out for Ouagadougou and Kumasi, representing the two major savanna biomes in West Africa (Sudan Savanna and Guinea Savanna). Previous field experimental data on the wide-spread cowpea genotype Asontem from a P-deficient soil at Kumasi (Ghana) were used to validate the SIMPLACE crop model solution. The model was able to simulate the impact of irrigation and fertilizer management on cowpea growth and yield assessment with adequate accuracy. Compared to historic simulations of the biomass and yield of cowpea, the model solution projected higher above ground biomass, and yield under the pre-dominant low input cropping systems for all the three SSPs as a result of the rise in CO2 and in spite of slightly shorted growing cycle length in both locations.

Preliminary Studies on Cowpea (Vigna unguiculata) Offers Opportunity for Selection in the Guinea and Sudan Savanna Agro Ecologies of Ghana

Genotype by environmental interaction is important for breeding improved cowpea genotypes. The study was designed to identify promising inbred lines with high yield potential, stable mean yield with specific adaptation to a particular environment or environments. The study was conducted at three locations namely Nyankpala, Tumu, and Damongo. Twenty-two inbred lines plus 2 contrasting parents used to generate inbred lines were the test genotypes. Randomized complete block design with 4 replications was used. Seeds were planted at each location but were later thinned to one plant per hill. Each plot contained 5 rows of 10 plants per row with plant spacing of 60 cm between rows and 20 cm within rows with the number of entries being 24 plots giving the total plots as 96 plots for each location. Data collected were days to first flowering, 50% flowering, number of pods per plant, number of seeds per pod and hundred seed weight and grain yield. Data were subjected to analysis of variance using Gen Stat statistical package 12th edition. Combined analysis of variance across locations for grain yield were determine. Results showed significant genotypic differences among inbred lines for studied traits. significant genotype by environment interaction was observed for days to 50% flowering, ranging between 42 and 45 days. Number of pods per plant, number of seeds per pod and biomass also showed variable responses across locations. Phenotypic correlation analysis for days to flowering and maturity did not have any influence on yield, as genotypes 116, 189, 131 flowered within 43 and 45 days with corresponding yields of 1.89,1.82 and 1.7 tonnes per hectare. Yield variability showed the possibility for selecting location specific adapted lines as well as across all three locations.

Evaluation of Improved Cowpea Genotypes for Yield and Resistance to Scab Disease in Uganda

Cowpea is one of the most important legume food crops in Uganda. However, grain yields as low as 400 kg ha−1 have been recorded in farmers’ fields despite a grain yield potential of 3,000 kg ha−1. Cowpea scab is a major production constraint, causing yield losses of up to 100%. Three hundred ninety (390) improved cowpea genotypes were evaluated for yield and scab resistance for one (1) year at NaSARRI, Serere, Uganda using an alpha lattice design with two replications. The analysis of variance showed significant differences (p < 0.05) for grain yield, scab severity, incidence, and area under disease progress curve (AUDPC) among genotypes, seasons, and for genotypes by seasons interactions. The mean grain yield of 981.6 kg ha−1 was recorded across the cowpea genotypes with genotype, TVU-1280 having the highest grain yield of 1790.8 Kg ha−1. The cowpea genotypes; 1195K-1093-5-A, TVU-2968, SanZi, Taef-14-inhaca.E, TVU-205-8 and TVU-13485 had low scab severity(range:8.0 - 9.0).Cowpea genotypes; Taef-14-inhaca.E(33.7%), TVU-14633(26.7%), TVU-151144(30.6%), and Cosiriele (31.4%), had low scab incidence. Low AUDPC (range: 788.8-883.5) was observed in cowpea genotypes; 1195K-1093-5-A (775.0), TVU2968(788.8), TVU-14633-A (883.8), and TVU-13388 (857.5). Grain yield had a significant negative correlation with AUDPC (r = −0.2279, p < 0.001) and scab severity (−0.600, p < 0.001). Scab severity showed a strong significant and positive correlation with AUDPC (r = 0.6873, p < 0.001). The cowpea genotypes; 1195K−1093−5−A, TVU−2968, TVU−15114, SanZi, and Taef−14− inhaca.E could be used as breeding lines for introgressing scab resistance into cultivars with farmer preferred traits.

Genetic diversity and importance of agronomic traits in cowpea genotypes in conditions of low technological level in Piaui

Genetic diversity and importance of agronomic traits in cowpea genotypes in conditions of low technological level in Piaui

Additive Main Effect and Multiplicative Interaction Stability Analysis of Grain Yield Performance in Cowpea Genotypes across Locations

Additive Main Effect and Multiplicative Interaction Stability Analysis of Grain Yield Performance in Cowpea Genotypes across Locations

Selection of Cowpea [(<i>Vigna unguiculata</i> (L.) WALP] Genotypes for Drought Tolerance Using Selection Indices

Cowpea [(Vigna unguiculata (L.)] is one of the most important arid legumes cultivated for pulse and forage production. However, in cowpea, not much is known about the base index selection method in breeding for drought tolerance. Consequently, the present study has been conducted to: 1) evaluate the yield performance of cowpea genotypes under artificial drought and well-watered condition; 2) develop a base index using multiple traits for ranking genotype performance. The experiment was a 25 × 2 factorial laid out in a Randomized Complete Block Design (RCBD) with three replications. The experiment was carried out in the screen house at the Department of Horticulture at KNUST. The result showed that KPR1-96-73, Simbo, CZ06-4-16, Wilibaly and Agyenkwa were high yielding in well-water condition while Ghana Shoba, Sangaraka, NKetewade, Ghana-Shoni and Korobalen were high yielding genotypes in water stress condition. The average yield reduction was 60.6% for grain respectively. The biplot displays revealed four groups among the genotypes tested which was based on their yielding capacity and drought tolerance. In cluster B high yielding and drought tolerant genotypes were identified, high yielding and drought susceptible have been identified in cluster A, low yielding and drought tolerant in cluster D, and lastly low yielding and drought susceptible in cluster C. Genotypes in cluster B, were the best due to the fact that it combines high yield and tolerance to drought. They were Ghana Shoni, Nketewade, Sangaraka and Ghana shoba. These genotypes might be suitably employed in further drought tolerance breeding program of cowpea.

Minerals and anti-nutritional components of raw, cooked and sprouted cowpea genotypes

Minerals and anti-nutritional components of raw, cooked and sprouted cowpea genotypes

Screen House Assessment of Cowpea [(<i>Vigna unguiculata</i> (L.)] Genotypes for Drought Tolerance Using Selection Indices

Cowpea [Vigna unguiculata (L.)] is one of the most important arid legumes cultivated for pulse and forage production. Drought is one of the most damageable constraints to crop production impacting negatively food security. The potential of cowpea to address food security is well established. However, not much is known about the base index selection method in breeding cowpea for drought tolerance, which is important for yields. Consequently, the present study has been conducted to: 1) evaluate the yield performance of cowpea genotypes under artificial drought and well-watered condition, 2) ranke genotype performance using selection indices, and 3) assess relationship between agronomic traits and yield. The experiment was the 2 watering conditions laid out in a Randomized Complete Block Design (RCBD) with three replications. The experiment was carried out in pots under screen house at the Department of Horticulture at KNUST. The result showed that KPR1-96-73, Simbo, CZ06-4-16, Wilibaly and Agyenkwa were high yielding in well-water condition while Ghana Shoba, Sangaraka, Nketewade, Ghana Shoni and Korobalen were high yielding genotypes in water stress condition. The average yield reduction was 60.6% and 16% for grain and fodder yield respectively. The biplot displays revealed four groups among the genotypes tested which were based on their yielding capacity and drought tolerance. In cluster B high yielding and drought tolerant genotypes were identified, high yielding and drought susceptible have been identified in cluster A, low yielding and drought tolerant in cluster D, and lastly low yielding and drought susceptible in cluster C. Genotypes in cluster B were best due to the fact that it combines high yield and tolerance to drought. They were Ghana Shoni, Nketewade, Sangaraka and Ghana Shoba. These genotypes might be suitably employed in further drought tolerance breeding programs of cowpea. Significant relationships were observed between agronomic trait and yields under drought condition.

Adaptability and yield stability of cowpea genotypes in Mato Grosso do Sul

Adaptability and yield stability of cowpea genotypes in Mato Grosso do Sul

Effect of Salicylic Acid on Physicochemical Parameters and Accumulation of Compatible Solutes in Three Genotypes of Cowpea under Arsenic Stress

Cowpea is a legume widely cultivated across the world but its growth may be limited by contamination with non-essential elements among which are arsenic. The present study was designed to examine the effect of salicylic acid on physicochemical parameters and accumulation of compatible solutes in cowpea under arsenic stress.

Screening of Cowpea Genotypes for Growth, Yield and Cowpea Mosaic Virus Incidence

Eighteen cowpea genotypes against cowpea mosaic virus disease under zero tillage condition were screened during pre Kharif season of 2013, 2014 and 2015 at the field in Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal.Significant variation was observed for different genotypes with respect to cowpea mosaic virus, growth, yield and qualities. Highest pod yield was recorded in Kashi Kanchan (16.42 t/ha) which was statistically at par with Kanak (16.30 t/ha). Genotypes Bidhan Barbati 1, Bidhan Barbati 2, Kaberee and Pusa Komal were recorded without disease incidence i.e.immune while, Kanak, Pusa Phalguni Gold and Lafa Charulata exhibited highly resistance against cowpea mosaic virus. It was observed that cowpea mosaic virus incidence was negatively correlated with chlorophyll content, number of pods/plant, pod yield, leaf phenol content and leaf peroxidase content whereas, it was positively correlated with canopy temperature, days to flowering and first harvest. Bangladesh J. Bot. 51(4): 817-820, 2022 (December)

Screening of Cowpea Genotypes for Field Resistance to the Spotted Pod Borer (Maruca vitrata)

Background: Cowpea [Vigna unguiculata (L.) Walp.] is an important legume crop known for its nutritional value. However, the cultivation of this crop is greatly hampered by a destructive pest, a spotted pod borer (Maruca vitrata Fab.). Keeping the caustic nature of the pest in view, the present study was undertaken. Methods: Field evaluation of thirty cowpea genotypes was carried out by raising cowpea plants in an open field. Observations on the M. vitrata incidence were recorded at three days’ intervals starting from the development of the first buds to the end of flowering. Based on the level of infestation of buds, flowers and pods, the cowpea genotypes were categorised into four groups viz., resistant, moderately resistant, susceptible and highly susceptible. Results: Results of the study revealed a significant variation between the genotypes in terms of total damage (0.21 to 48.46%). Genotype IC 2918 recorded remarkably low damaged (0.12%) and was on par with Palakkadan thandan payar, Hridya, EC 300039, EC 101216, EC 98668, IC 39945, IC 52110, IC 39922 and IC 39916. The genotype Bhagyalaxmi recorded the highest damage (48.46%) followed by the variety Lola (30.04%). Flower buds were more susceptible to M. vitrata and suffered severe damage as compared to flowers and pods. Conversely, genotypes EC 98668 and IC 39922 were free from bud damage. Genotypes EC 300039, EC 98668, IC 52110, IC 39945, IC 2918 and IC 39922 recorded no flower damage and Palakkadan thandan payar, IC 39945, IC 2918 and IC 39947 recorded no pod damage.

Genotype × Environment Interaction Influence Secondary Metabolite in Cowpea Infested by Flower Bud Thrips

Secondary metabolites are among the major contributors of host-plant resistance. Cowpea produces secondary metabolites that are known to enhance resistance to insect pests including flower bud thrips. However, environmental conditions tend to affect the production of secondary metabolites, thereby affecting the response of the host plants to insect pest. The objective of this study was to determine the effect of the genotype × environment interaction on the production of secondary metabolites and flower bud thrips resistance in cowpea. Six cowpea genotypes were evaluated for flower bud thrips damage and the contents of flavonoids, antioxidants, phenolics, proteins, lignin, tannins and reducing sugars in four environments with varying temperatures and rainfall patterns. The data collected were subjected to the analysis of variance and genotype and genotype × environment (GGE) analysis. Flower thrips damage, and the contents of flavonoids, antioxidants, lignin, tannins and reducing sugars varied significantly (p < 0.001) among genotypes. Genotype Sanzi produced high levels of antioxidants, while TVU-9820 led in phenolic concentrations respectively. Metabolite contents were significantly (p < 0.001) different among environments, with the long rain season of field experiments led to increased production of flavonoids, proteins, lignin and tannins. A resistant genotype, TVU-3804, produced relatively stable contents of flavonoids, antioxidants, phenolics, proteins and reducing sugars across environments. In this study, the environment influenced the concentration of the metabolites, which in turn affected the cowpea’s resistance to flower bud thrips.

Inheritance of Secondary Metabolites Associated With Cowpea Resistance to Flower Bud Thrips

Plant secondary metabolites are part of defense mechanism that form host plant resistance. Understanding the inheritance of secondary metabolites is preliquisite for conducting an effective plant breeding program. The objective of this study was to determine the mode of inheritance of secondary metabolites associated with resistance of cowpea to flower bud thrips. Five cowpea genotypes with varying level of resistance to flower thrips were crossed in full diallel method 1. The F2 were evaluated for secondary metabolites and flower thrips damage in field and screen house. The results confirmed genotype TVU-3804 as resistant, and TVU-9820 and TVU-201 as susceptible to flower bud thrips. Flavonoids, antioxidants, proteins and reducing sugars had significant (p < 0.001) GCA and SCA effects indicating the importance of additive and dominance effect in controlling resistance of flower bud thrips. In addition, significant reciprocal observed for crosses such as Lori Niebe × Sanzi and Sanzi × TVU-3804 for flavonoids and antioxidants is an indication that maternal effect is key in governing resistance of cowpea to thrips. The broad sense heritability was low for secondary metabolites except flavonoid which had moderate value, an indication that delaying selection to a later generation would yield better results while breeding for resistance to flower thrips based on secondary metabolites. The results of this experiment showed that it is possible to use secondary metabolites to breed for improved cowpea resistance to flower bud thrips.