Participatory varietal selection among elite cowpea genotypes in northern Namibia (original) (raw)
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Acta Agriculturae Scandinavica, Section B — Soil & Plant Science, 2019
Cultivar development of cowpea with increased grain yield depends on evaluation and selection of genetically unique and complementary breeding lines. The objective of this study was to evaluate cowpea collections using agronomic traits to select promising parents to develop breeding population. Twenty-two cowpea genotypes were field evaluated using a randomised complete block design with three replications in two locations in South Africa. Analysis of variance revealed significant genotypic (G) and locations (L) differences for all agronomic traits evaluated. Significant differences were also observed for most of the traits due to G X L, G X Year (Y), L X Y and G X L X Y interactions effects. The genotypes tested at two locations showed considerable genetic variation for the following agronomic traits that varied for number of leaves (NL) (20.08-179.78), leaf length (LL) (12.36-67.72 cm), leaf width (LW) (4.78-22.02 cm), number of branches (NB) (6.81-13.85), number of pods per plant (NPPP) (14.33-54.04), number of seeds per pod (NSPP) (11.7286.28), pod diameter (PD) (5.75-22.73 mm), plant height (PH) (6.57-233.71 cm), pod length (PL) (3.94-100.92 mm), hundred seed weight (HSWt) (8.11-49.52 g) and grain yield (GY) (0.10-1.48 t ha −1). Grain yield was significant and positively correlated with all of the traits except leaf length. The principal component analysis (PCA) identified four principal components (PCs) contributing to 73.62% of the total explained variation amongst the tested genotypes. The selected cowpea genotypes for most of agronomic characteristics are useful and candidate genetic resources for the development of breeding population in cowpea breeding and enhanced production and productivity for food and nutrition in the country.
Heliyon, 2022
Identification and selection of cowpea genotypes possessing suitable agronomic attributes is key for cultivar development to increase production. The objective of this study was to evaluate cowpea genotypes using agronomic traits to aid selection and identification of best genotypes for adoption and breeding to develop highyielding cultivars. Agronomic traits of 20 cowpea genotypes were evaluated under Tompi Seleka and Polokwane environments using a completely randomised block design. Significant (P 0.01) genotype effect was identified for agronomic traits, whereas environment effect was significant (P 0.05) for number of productive branches (NB), leaf width (LW), leaf length (LL), hundred-seed weight (HSW) and grain yield (GY). Significant genotype-by-environment interaction effect was observed for pod length (PL), pod width (PW) and number of seeds per pod (SPP).
International Journal of Biosciences, 2024
Cowpea (Vigna unguiculata L. Walp) is an important legume serving multiple roles for many low-income farmers. However, its productivity remains low and discrepancies exist in selection and acceptability criteria. Including farmer-preferences could help develop adoptable varieties. This study surveyed present production practices among 64 representative smallholders to inform breeding objectives. A cross-sectional survey design was used to collect data analysed using SPSS Software version 23. Education, land, drought, seed sources, improved variety, seed availability, and pests significantly (P<0.001) affected cowpea production. Most respondents were married, aged 31-40 years, and had primary, secondary or tertiary education. About 60.9% practiced mixed cropping, while 60.9% grew cowpea with multiple crop cycles. Whereas majority relied on rain, 32.8% strongly agreed that drought determined cowpea variety adopted. Acreage cultivated was <1 acre by 84.4% respondents. Farmers named 7 insect-pests as major threats, with aphids leading (67.2%). Five diseases were major constraints, with cowpea mosaic virus leading (64.1%). Majority (68.8%) grew cowpea for dual usage as grains and leafy vegetables. Farmer-preference revealed that leaf texture, seed colour and availability traits determine variety choice. Households totalling 46.9% preferred medium leaf texture with delicious (28.1%), sweet (26.6%) or bitter (12.5%) taste. There was a significant association between region and drought (χ 2 =15.57, df=4, P=0.004), region and production purpose (χ 2 =16.49, df=2, P=0.004), as well as region and utilisation (χ 2 =8.44, df=1, P=0.004). In Western 38.2% and Eastern 63.3% respondents strongly agreed that drought was a constraint. A total of 70% and 52.9% respondents in Eastern and Western, respectively, grew cowpea as a mixed crop. Most respondents (47.1%) in Western grew cowpea for leafy vegetables, while 86.7% in Eastern grew for dual-usage. This study recommends use of present baseline information on key selection criteria in generating demand-led variety design during breeding.
Plant Breeding and Biotechnology
Climate change has imposed greater challenge on cowpea production in the savannah ecology of West Africa sub-region in the recent time, however, development of varieties that combined resilience (stability) and precocity with high seed yield would be a sustainable approach to mitigate this problem. To this end, nine advanced breeding lines were evaluated along with two commercial varieties across three locations in guinea savannah ecology, using a randomized complete block design of three replications. Results obtained for seed yield and yield components indicate that the eleven cowpeas exhibited substantial variability for all plant traits studied and implications discussed. Additive Main Effect and Multiplicative Interaction (AMMI) analysis however revealed that the variations recorded were substantially attributable to genotypic component (70-80%) and less of environment (0.7-7.0%), a measure of phenotypic stability of these cowpea lines. However, seed yield and yield components vary significantly across the three locations, which further emphasize the important role of soil and climatic variables to cowpea production. In this study, two varieties (IT07K-299-6 and IT11K-61-82) consistently combined high seed yield (＞ 2 tons/ha) with precocity across the three locations, and could be multiplied for distribution to farmers as short-term intervention for yield increase. Reduced seed viability of these varieties reflects seed storage challenge in cowpea farming. In addition to significant contributions of some yield components to seed yield, there was evidence of strong association between precocity and high yield, and its implication for cowpea improvement discussed.
Journal of Plant breeding and Crop Science, 2018
Ethiopia is claimed to be a center of diversity for cowpea production. The crop is the most drought tolerant and could help the country overcome the recurrent drought problem; however, the yield is very low due to lack of effort to develop varieties. This research was conducted to evaluate the stability of cowpea genotypes and to estimate the magnitude of genotypes by environment interaction (GEI) effect on grain yield. Sixteen cowpea genotypes were tested at seven environments in an experiment laid out in a 4 × 4 triple lattice design during 2016/17 cropping season. The combined analysis of variance over environments showed significant differences among genotypes and environments, along with significant effect of GEI on grain yield, days to flowering, days to maturity, plant height and pods per plants. Analysis of variance for grain yield from AMMI model indicated the contribution of genotype and environment, with GEI accounting for about 63.3, 5.3 and 29.7% of the total sum of squares, respectively. The result indicated that environments contributed much to the observed variations suggesting the need to test cowpea genotypes in diverse environments. Considering all stability parmeters, viz; deviation from regression (S 2 di), coefficient of regression (bi) from ER's model, IPCA1, IPCA2 and AMMI stability value (ASV) from AMMI model, GGE biplot and variety TVU was identified as the most stable with mean yield above the mean grain yield of genotypes. Two genotypes: IT-99K-1060a (1398.8 kg/ha) and 86D-378 (1377.1 kg/ha) had first and second highest yield, identified as responsive to both environments but more to favorable environments suggesting the need to further test and develop as varieties. The other two genotypes: 95K-1095-4A and 93K-619-1, identified as unstable and highly responsive to environments suggested to consider the genotypes as candidate varieties where they performed best. Melkassa, Sekota and Jinka were identified as more descrimnating environments, whereas Arbaminch and Kobo were ideal for selecting superior genotypes; however, Babile and Meisso were non descrimnating environments.
This study was conducted to evaluate 12 advanced cowpea breeding lines developed from 27 local cowpea populations of Turkey using single plant selection based on some plant characteristics and fresh pod yield in comparison with Akkız-86 and Karagöz-86 control cultivars. Field experiments were arranged in randomized complete block design with three replications and conducted at Kurupelit and Ambarköprü locations of Samsun, Turkey in 2005 and 2006. According to combined results, L3 was the superior line for fresh pod yield by 18.0 t ha- 1. It was followed by L12, L13 lines and Karagöz-86 cultivar. Genotype x environment interaction was significant (P<0.01) for fresh pod yield. Stability analysis revealed that L3 line showed the best adaptation in optimal environmental conditions among all lines/cultivars. All cowpea lines/cultivars were found to be moderately adaptable to all environmental conditions with the exception of L3, L12, L1 and L9. Based on the two years study results, L3...
GENOTYPE-ENVIRONMENT INTERACTION OF SOME IMPORTED COWPEA (Vigna unguiculata, L.) ACCESSIONS
Developments of cultivars with stable and sustainable yields under diverse environmental conditions become the main objective of breeding programs nowadays. Currently, only five released cowpea cultivars are available in Egypt. Hence, introducing new resources of this crop is needed for genetic improvement. Seventeen genotypes of cowpea (Vigna unguiculata L.) were introduced from International Institute of Tropical Agriculture (IITA), Nigeria were used for this purpose. Two field experiments were conducted during the summer seasons of 2013 and 2014 to test these genotypes with local adapted check variety Kafr El-Sheik concerning some vegetative and yield components traits as preliminary evaluation. The genetic materials were evaluated in a randomized complete blocks design with three replicates. The behavior of most studied traits differed along the two seasons, except no. of leaves/plant and no. of seeds/pod. Significant effects (P<0.05) of genotype, year and interaction for many of the studied traits over the cowpea genotypes were observed by factorial analysis. A highly significant genotypes x year interaction was obvious for most traits. The coefficient of genetic variation ranged from 20.23% to 63.65%. Number of branches and number of leaves traits had the highest heritability and genetic variability. The genotype IT97K-499-35 gave the highest yield per feddan with 17.7% increase over the check variety. Multivariate cluster analysis resulting in formation of 9 groups based on Mahalanobis dissimilarity matrix and Tocher method. The genotypes IT04K-221-1, IT07K-299-4 and IT07K-243-1-5 which recorded high mean yield with low ecovalence (Wi), besides their superiority over check local variety, they have moderate level of stability and could response well to environmental improvements.
Cowpea, an important grain legume in the tropics and sub-tropics; serves as a source of protein in the diets of the people with tremendous ability to fix atmospheric nitrogen for soil improvement. Ten (10) genotypes of cowpea were grown during the rainy season of 2013 to study the interrelationship among quantitative traits. Estimates of phenotypic and genotypic coefficients of variation, broad sense heritability, and genetic advance as percent of mean and correlations were performed on 20 quantitative traits. The experiment was laid out in a randomized complete block design (RCBD) with three replications at the Research Field of the. Genotypes differed significantly at (P ≤ 0.01) for all traits studied which showed the existence of sufficient genetic variability among the tested genotypes. High broad sense heritability values for all traits studied except for plant height (moderate) shows that these traits are less influenced by environmental effects; which make them effectively transmitted to the progeny. The high positive genotypic and phenotypic correlations between numbers of pods per plant, number of seeds per pod, number of seeds per plant and seed weight indicates that selection for these will result in increase in yield. Keywords Broad sense heritability, Genetic advance as percent of mean, Cowpea, Genotypic coefficient of variation, Phenotypic coefficient of variation
Genetic variability in exotic cowpea (Vigna unguiculata L.) genotypes
2024
Genetic variability plays a crucial role in hybridization and the development of crops with desirable traits. This study, conducted at the Regional Agricultural Research Station of the Bangladesh Agricultural Research Institute in Chattogram, focused on assessing genetic diversity, correlations, and path coefficients related to yield and other traits in 31 cowpea genotypes. The experiment, designed as a randomized complete block with three replications, revealed significant differences among the genotypes for all traits measured, as confirmed by analysis of variance. While most traits showed minimal differences between phenotypic and genotypic variances, plant height and yield per plant were more significantly influenced by environmental factors. The coefficients of variation were low for days to first flowering, days to 50% flowering, days to maturity, and days to harvesting; moderate for seeds per plant; and high for other traits. Plant height, thousand-seed weight, and yield per plant exhibited high heritability and substantial genetic advance, suggesting that direct selection for these traits would be effective due to their additive genetic control. The correlation analysis indicated significant positive relationships between yield per plant and several flowering and maturity traits at both the genotypic and phenotypic levels. Path analysis identified plant height, days to 50% flowering, days to harvesting, seeds per plant, pods per plant, and thousand-seed weight as having positive direct effects on yield per plant, implying that selection for these traits could enhance cowpea yield. Among the evaluated genotypes, E25 stood out as the highest yielding with 533.33 g yield per plant, early maturity at 84 days after sowing, moderate thousand-seed weight (124.33 g), seeds per plant (13.87), and plant height (103.33 cm), making it a promising candidate for hybridization. This research provides valuable insights for cowpea breeding programs, highlighting the importance of selecting specific traits like plant height, flowering time, and thousand-seed weight to develop high-yielding, resilient cowpea varieties adaptable to diverse agricultural conditions.
Experimental Agriculture, 2019
SummaryComparative analysis of preferences and key criteria for selecting cowpea (Vigna unguiculata L. Walp.) varieties was conducted using the data collected from farmers’ participatory varietal selection (FPVS) activities conducted over 3 years with a total of 2401 farmers (1230 male and 1171 female) in 13 villages in Tougouri department in northern region and Tiéfora department in southern region of Burkina Faso in West Africa. Over the 3 years, farmer criteria for variety selection remained basically stable, but some variations among the regions and years were noticed. Grain yield was the most common and the most important criterion for farmers’ choice in both regions. Farmers in Tougouri (north) put more emphasis on early maturity (90%) and drought resistance (19.7%) as selection criteria than farmers in Tiéfora (south). Farmers in Tiéfora placed statistically significant importance on seed colour and plant type, while farmers in Tougouri did not, and for these selection criter...