GENETICS OF MORPHINANE ALKALOIDS IN OPIUM POPPY (PAPAVER-SOMNIFERUM)

An experiment was carried out during winter season of 1990-91 on additive-dominance model for 2 crosses ('NBRI 1' x 'BR 222' and 'NBRI 2' x 'BR 222') to study the gene actions involved in the inheritance of morphinane alkaloids (morphine, codeine and thebaine) in opium poppy (Papaver somniferum L.). Non-significant chi-square (chi2) showed the validity of additive-dominance model. Dominance (h) effect was higher than additive (d) effect. Digenic interactionss indicated the prevalence of additive x additive (i) gene effect for morphine and dominance x dominance (l) for codeine and thebaine in both the crosses. The sign of dominance (h) and dominance (l) indicated duplicate gene action for all the morphinane alkaloids. Recurrent selection involving desired recombinants may be utilized to improve the alkaloids.