Inheritance studies of grain shape and aroma traits of rice genotypes in Uganda rice germplasm

Abstract

A study was conducted to determine the mode of inheritance for grain shape and aroma traits of lines in the Uganda rice germplasm. Five aromatic and four non-aromatic rice lines were crossed in screen house using North Carolina Design II at the National Crops Resources Research Institute, Uganda. The resulting F 2 seeds and their parents were planted in the field using complete randomized block design in two replications. The grain shape and aroma intensity of the harvested F 3 seeds on per hill basis were determined in laboratory using instrumental and sensory evaluation procedures, respectively. The results revealed that the inheritance of grain shape and aroma traits were influenced by both additive and non-additive gene actions, but with the grain shape being dominated by additive gene action and the aroma by non-additive gene action. In addition, Supa 3, Supa 5 and Supa 1052 rice lines exhibited good general combining ability effects for the shape trait while Supa 3 and MET 13 were good general combiners for the aroma trait. The superior cross combination from Supa 3 x Supa 5 for grain shape and Supa 3 x MET 13 for aroma trait could be used for selection of the relevant traits at advanced stages of the breeding cycles.