Inheritance pattern of resistance to Fusarium wilt (Fusarium oxysporum f. sp sesame) in sesame

Abstract

Fusarium wilts (Fusarium oxysporum f.sp. sesame) is among of the most destructive soil-borne disease of sesame in Uganda. The disease may cause yield loss of up to 100% if not controlled. Breeding and use of resistant varieties is the most economic and eco-friendly solution to the disease since majority of sesame growers are resource constrained. Some genotypes were reported to be moderately resistant to the disease in Uganda. However its nature of inheritance was not studied. Successful breeding requires selection of suitable parents and whose pattern of inheritance of disease resistance is known. In this study, eight parental genotypes of sesame with different levels of resistance to Fusarium wilt pathogen were used in a full diallel to produce F1 progenies. The eight parents and F1 progenies were evaluated in the screen house under high pathogen pressure through artificial infection in an Alpha Lattice Design of three replicates. The results revealed that additive and non-additive gene actions contributed to controlling resistance to Fusarium wilt. However non-additive were more predominant which were signposted by moderate Baker’s ratio (53.9%) and low Coefficient of Genetic Determination narrow sense (h2 = 45.1%). Moreover, the study indicated that maternal effects have influence toward resistance to Fusarium wilt in sesame. Among eight parents used parent Sesim 2 (with EM% GCA effect 7.32, and DI% GCA effect -4.02) and EM15-1-5 (with EM% GCA effect 3.07%, and DI% GCA effect -11.58%) were good combiner parents for transmitting resistance and are recommended for use in breeding for Fusarium wilt resistance. Key words: Fusarium wilt, inheritance, incidence, resistance, sesame,