Heterosis And Combining Ability Estimates In 6x6 Half-Diallele Cross Of Roselle (Hibiscus Sabdariffa L.)

Abstract

Half diallele analysis was used to identify the high heterotic crosses and their relationship in terms of general combinig ability (GCA) and specific combining ability (SCA) of 6 roselle cultivars evaluated in two locations Yola and Mubi, located within latitude 7 0 14' North, Longitude 12 0 38' East and Latitude 10 0 03' North, Longitude 13 0 07' East respectively in Adamawa State, Nigeria. The results showed significant entries, parents and crosses for all the traits studied in the individual and also in the poolled analysis, suggesting that roselle populations were highly variable for all the traits and therefore would most likely respond to selection. Significant GCA and SCA variances were also obtained in all the traits implying that both the additive and non- additive gene effects were operating in the genetic expression of the traits. The non-additive gene effect was however greater in magnitude as shown by the δ 2 GCA/δ 2 SCA ratios, which were all less than unity. The combining ability analysis of parents also revealed that Gerio-AB3, Bazza-AB2 and Bazza-AB1 yielded consistently higher general combining ability effect for most of the traits, indicating that their crosses should produce desirable segregates for the improvement of calyx yield of roselle. SCA effects identified Bazza-AB2 x Gerio-AB2, Bazza-AB1 x Gerio-AB3 and Bazza-AB1 x Michika-AB1 as the best crosses. The hybrid Bazza-AB2 x Gerio-AB2 exhibited heterosis of up to 46.01 % over the higher yielding parent.