Review on methods of maize breeding for tolerance or resistance of Striga hermonthica
Striga hermonthica is a major limiting factor in maize cultivation in sub-Saharan Africa. Based on environmental factors such as soil fertility, climatic conditions and genotype, this can result in a yield loss of up to 100%. The aim of this article is to review maize breeding methods for resistance/tolerance to Striga hermontica and to highlight the efforts made to overcome yield reduction due to Striga hermonthica. The International Institute of Tropical Agriculture (IITA) has made significant progress in developing several early inbred maize lines, open-pollinated varieties and hybrids containing Striga resistance genes. However, the levels of striga resistance of the available precocious inbreds and hybrids are not as high as desired. This is because the Striga seed bank is added to the soil after each growing season. There is therefore a need for increased Striga resistance in the available genotypes. Since resistance to S. hermonthica in maize is regulated by many genes, breeding for Striga-resistant cultivars using traditional approaches has been less effective and time-consuming. The identification of QTLs associated with Striga resistance/tolerance would facilitate the rapid development of Striga resistant/tolerant maize genotypes.