National Bureau of Plant Genetic Resources, New Delhi, 110012, India
1Present address. National Research Centre for Groundnut, Timbawadi, Junagadh, 362 015, India.
*Part of the thesis of the first author for the Ph. D. degree of Post Graduate School, IARI New Delhi-1978.
The parents, F1, F2 and first generation backcrosses of three Datura innoxia crosses were investigated for plant height (cm), internode number, capsule number, stem weight, leaf yield and seed yield per capsule. The estimates of gene effects showed that all the three types of gene actions, viz, additive, dominance and epistasis were present in varying proportion for all the six characters under study. Dominance and epistastic components were several times larger than additive effects for all the characters in majority of the crosses. Duplicate epistasis was found to contribute significantly to plant height, internode number, capsule number and seed yield per capsule. However, additive effects were the main source of genetic variation for capsule number, stem weight and leaf yield in cross EC 32777 x IW 2205 indicating that early generation selection for high leaf yield should be effective in this cross.
