Genetic variability for Grain and fodder yield in cowpea [Vigna unguiculata (L.) Walp]

Olayiwola M.O. 1,2 and P.A.S. Soremi2 1 International Institute of Tropical Agriculture, PMB 5320,

Ibadan, Oyo State, Nigeria2 Federal University of Agriculture, Abeokuta P.M.B. 2240,

Abeokuta, Ogun State, Nigeria.

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Introduction

• Plant breeders play crucial role in the agriculture value chain

• Breeders rely immensely on the existing variability within the germplasm for crop improvement

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Introduction contd.

• Knowledge and magnitude of genetic control of variability are critical to the success of any breeding program

• Genetic analysis shows the gene effects underlying a trait of interest

• Heritability and genetic advance are important pointers to the gene action controlling a trait in crops

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Justification

• Cowpea is highly important in human diet and livestock feed due to its high protein content.

• Nigeria is the largest cowpea producer, accounting for 61% and 58% of total Africa and world production respectively.

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Justification contd.

• Yet Nigeria is the highest consumer and importer of the crop (Lowenberg-DeBoer and Ibro, 2008).

• Therefore, it is important that research aimed at enhancing the development of high performing cowpea varieties be encouraged in west and central Africa

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Objective

• The study aimed to provide information on the magnitude of genetic variability among cowpea genotypes for further use in cowpea improvement

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Materials and Methods

• Research location• Eleven cowpea genotypes were sourced from

GLIP-IITA• Field layout, design and cultural practices

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Materials and Methods contd.

• Data were collected on pod, seed and dry fodder yield.

• And subjected to combined ANOVA• The genotypic and phenotypic variances and

coefficients of variation were determined• Broad-sense heritability and expected genetic

advance were estimated

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Results and Discussion

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• Genotypic effect was highly significant for all traits

Fig 1 Phenotypic and genotypic variances of pod, seed and dry fodder yields

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Results and Discussion contd.

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Table 1 Mean performance of cowpea genotypes evaluated for pod, seed and dry fodder yieldGenotypes Pod Yield Seed Yield Dry Fodder Yield

IT04K 332-1 588.1bc 451.7bc 141.4e

IT04K 333-2 675.1bc 497.4bc 156.2cd

IT06K 134 436.3c 260.1c 85.6g

IT06K 242-3 875.3ab 644.2ab 193.3a

IT07K-303-1 384.6c 259.6c 145.3d

IT98K-573-1-1 864.9ab 589.8ab 125.4f

IT98K-573-2-1 866.4ab 616.0ab 228.5a

IT99K-1060 790.1ab 546.3b 161.4c

IT99K-494-6 1033.9a 807.3a 137.2ef

IT99K-529-2 1030.1a 694.0ab 160.1cd

IFE BROWN 711.2ac 477.0bc 170.8c

Means with similar alphabets along same column are not significantly different from one another using DMRT at P<0.05

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Results and Discussion contd.Table 2 Phenotypic (PCV) and genotypic coefficients of variation (GCV) for pod, seed and dry fodder yields

(PCV) and (GCV): low (< 10%), moderate (10-20%) and high (>20%).

Table 3 Heritability and Genetic Advance (GA) for pod, seed and dry fodder yields

Heritability: low (<30.00%), moderate (30-60%) and high (>60.00%).. GA : low (< 10%), moderate (10-20%) and high (>20%).

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Traits PCV GCVPod yield 54.9 34.7Seed yield 60.7 38.8Dry fodder yield 26.7 25.5

Traits Heritability Genetic AdvancePod yield 39.0 258.3Seed yield 41.1 203.1Dry fodder yield 91.0 71.8

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Conclusion• High genetic variability a pointer to potentials for

cowpea improvement• The combination of heritability and genetic advance

gives better accuracy in predicting the selected value for a trait.

• Dry fodder yield alone combined high heritability with high genetic advance which indicates high additive genetic variance for the trait.

• IT99K-494-6 and IT98K-573-2-1 could serve as good parent stock

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