Genetics of Resistance to Groundnut Rosette Virus Disease among Groundnut Landraces in Uganda

Groundnut rosette virus disease (GRVD) is caused by a trio of viral components and is a major disease that can cause 100% crop losses in an epidemic situation. Thus, continued effort to develop resistant groundnut cultivars is critical in sub-Saharan Africa (SSA), the only region in which the disease exists. In this study, the mode of inheritance of GRVD resistance will be determined for three resistant introduced lines (Serenut 2, 3 and 8). These lines, together with one aphid resistant line, were crossed with four susceptible land races in a line-by-tester mating scheme. F2 segregants arising from 16 F1 crosses, along with parental lines, were planted in the field in an alpha lattice design with 3 replications. Inoculation is being done using the infector row technique, which is known to maintain a high disease inoculum pressure in the field. Genotypic differences will be evaluated using GCA and SCA effects estimated from the data for disease incidence. The narrow and broad sense coefficients of genetic determination, type of gene action, heritability and the number of genes conditioning resistance to GRVD will also be determined.