Uncovering the inheritance mechanisms of yield and oil content in castor (Ricinus communis L.): a 21-generation study

This groundbreaking study is the first of its kind to investigate the genetic effects on seed yield and its constituent characters in castor, and specifically to explore linked digenic interactions in this crop species. The study used twenty-one generations, including P1, P2, F1, F2, F3, B1, B2, B11, B12, B21, B22, B1S, B2S, B1 × F1, B2 × F1, F2 × P1, F2 × P2, F2 × F1, B1 bip, B2 bip, and F2 bip, from two crosses of castor: SKI-346 × JI-35 (cross-1) and SKI-346 × SKI-215 (cross-2). The results of the study shed new light on the inheritance of these characters and provide valuable information for future research in this field. Special scaling tests were used to assess the significance of genetic effects, and the results showed that most of the characters exhibited significant genetic effects, including epistasis, which suggests that the expression of these characters was influenced by interactions between genes. Additionally, higher order epistasis and/or linkage were detected, indicating that the expression of these characters was also affected by interactions among multiple genes. The study found that duplicate type of epistasis was responsible for the inheritance of seed yield and its constituent characters in the two crosses of castor. A recommendation to improve the seed yield of castor is to utilize a combination of recurrent selection and pedigree breeding approaches over several cycles.