Maize streak virus (MSV) transmitted by Cicadulina leafhoppers, causes severe yield losses in Malawi and many other countries south of the Sahara. Although yield losses due to MSV can be controlled to some extent by agronomic practices such as early planting and seed treatment with systemic insecticides, a much more reliable and environmentally sound strategy would be to breed cultivars with a high level of tolerance to MSV. The purpose of this study was to determine the relative contribution of additive and non-additive variation in the genetic determination of resistance to maize streak virus and to estimate the general and specific combining ability effects of inbred lines using diallel analysis. A better understanding of the genetics of MSV disease resistance is needed to support plant breeding programs as this would aid selection of parents, breeding procedures and population size for managing segregating populations. The results from a 10 x 10 diallel experiment, between streak resistant and streak susceptible lines, carried out at CIMMYT (Zimbabwe), showed that additive gene action was important in the inheritance of maize streak virus disease. The results showed that MSV resistance is polygenic and that it is inherited quantitatively. Recurrent selection procedures that utilize additive effects would be the logical approach to developing resistant maize hybrids in Malawi.

English

9801|AGRIS 9702

Jose Juan Caballero

CIMMYT Publications Collection