Screening of sesame genotypes for resistance against Fusarium wilt pathogen

Fusarium wilt is one of the most devastating diseases in sesame production in Uganda, caused by a fungus called Fusarium oxysporum f.sp. sesami. Its incidence ranges from 17.1 to 73.3%. Some sesame genotypes have been reported to resist Fusarium wilt; however, have not been precisely determined. In this study, 30 sesame genotypes that included released varieties, improved elite breeding lines and introductions were screened in the screenhouse under high pathogen pressure following artificial infection using five isolates of F. oxysporum f.sp sesami. The results revealed that sesame genotypes showed different response to the pathogen and thus disease development among the genotypes. The genotype effect was significant (P≤0.001) for disease incidence. Two genotypes (EM15-1-5 and Sesim 2) were identified and rated moderately resistant to Fusarium wilt (37.3 and 33.8%), respectively. Whereas, seven genotypes showed moderate susceptibility and 21 genotypes were susceptible for Fusarium wilt infection. No genotype was identified as being immune to the disease. It is noteworthy for sesame breeding programme in Uganda to continue evaluating other genotypes from existing germplasm which were not tested for resistance to Fusarium wilt in this study. Also more germplasm should be assembled and screened for resistance to the disease and other agronomic traits.