Cowpea and beans are the major legume crops dominantly gown in Zambia. They serve as cheaper sources of the dietary protein for human population, very nutritious as livestock feed and have potential to improve soil fertility when grown in rotation with cereals due to high residual nitrogen they leave in the soil. Aphid (Aphis crassivora) poses a significant threat to cowpea and bean production in Zambia, jeopardizing the country’s food security and livelihoods. In Africa, yield losses of approximately 70% due to aphid damage have been reported (Obopile, 2006). Aphids cause significant economic damage either directly through sap sucking on leaves, pods and flowers or indirectly by vectoring viral diseases such as mosaic viruses. In addition, heavy infestation results in stunting, delayed flowering, flower bud abortion and occasionally death of the plant.
Physical induced mutation with Gamma radiation provides an alternative method of creating genetic variation due to generation of new alleles not existing in the germplasm. Mutation has the ability to improve single or few economic and quality traits within the shortest possible time including plant characters from morphological to biological ones such as pest resistance (IAEA, 1987). While resistant mutant genotypes of cowpea and bean have been developed at the University of Zambia, mechanisms of resistance to aphids in these genotypes remain unknown. Furthermore, Silicon (Si) could potentially complement and sustain the plants’ defense against aphid attack.
International Atomic Energy Agency
University of Zambia
Harper Adams University