EVALUATION OF NEW COWPEA (Vigna unguiculata L. Walp) LINES FOR STRIGA (Striga gesnerioides Willd) RESISTANCE AND YIELD PERFORMANCE

Abstract

One of the most significant food mainstays in tropical Africa is the cowpea. However, parasitic weeds such as Striga gesnerioides, which has several distinct races, significantly reduces its productivity. The most dependable method for battling this parasite is the cultivation of resistant genotypes. Twenty new cowpea genotypes developed in the Coastal Savannah were evaluated under the Sudan Savannah condition for yield performance and resistance to Striga gesnerioides. The objectives were to: determine the agronomic and yield characteristics; Identify Striga resistant and susceptible lines among the genotypes as well as assess their morphological difference. The measured agronomic traits were days to flower initiation, days to 50% flowering, days to first maturity, maturity (90%), plant height, canopy size, leaf length, leaf width, number of pods per plant, number of pods per peduncle, pod length, seeds per pod, seed length, seed width, seed thickness, hundred seed weight (HSW), pod weight and grain yield per hectare. SSR-1 marker was used to screen these genotypes in the biotechnology laboratory at SARI. Most traits had significant coefficients of variation, and genotype variability was also substantial. Except for the number of pods per peduncle, all the features were likewise linked to high broad-sense heritability. The results of the study showed that 55% of the susceptible genotypes performed poorly in terms of hundred seed weight (HSW) yield, and this can be associated to Striga infestation. The results showed that only one genotype (UG-14) was resistant to the parasitic weed. This study also revealed high morphological variation among the tested genotypes. The non-susceptible line (UG-14) should be screened alongside other known Striga resistant genotypes to determine their genetic relatedness and with more Striga resistant markers.