Screening of Cowpea Mutants (Vigna unguiculata) for Resistance to Aphids (Aphis craccivora) in Burkina Faso

The cowpea aphid (Aphis craccivora Koch.) is a significant pest of cowpea crops, causing considerable damage to seed production. To identify cowpea genotypes resistant to aphids and demonstrating strong agronomic performance, fourth-generation genotypes (M4) derived from the cowpea variety Tiligré, which was irradiated with 150 Gy of gamma radiation, were screened with aphids using a free choice method under screen house conditions over three consecutive years. The genetic material included the parent Tiligré, two susceptible checks (KN-1 and KVx61-1), and two resistant checks (IT97K-556-6 and KVx295-2-124-99). Data on the number of adult aphids per plant, survival percentage, flowering date, pod and seed weight per plant, and the weight of 100 seeds were recorded. The investigation revealed that TiligréM157, TiligréM27, TiligréM42, and TiligréM56 reduced between 19 and 33% aphids’ multiplication compared to Tiligré non irradiated. The genotype TiligréM42, TiligréM157, TiligréM27 and TiligréM56 demonstrated better performance and produced more of 6% to 43% of Tiligré' grain weight. TiligréM42 produced more than 26% of IT97K-556-6 seed weight and TiligréM27 showed an increase of 21% IT97K-556-6 seed weight. The genotypes TiligréM42, TiligréM27, and TiligréM56 produced higher 100-seeds weight than Tiligré. The genotypes TiligréM27 and TiligréM42 were the earliest to flower compared to the parent Tiligré. Correlational analysis showed that the number of aphids negatively affected seed weight. In addition, the flowering date exhibited a strong positive correlation with the aphid score. Therefore, TiligréM42 and TiligréM27, appear to be proùiising cowpea genotypes for resistance to aphids and high yield production. In addition, the cultivation of these genotypes could contribute to reducing pesticide use in cowpea production.