The floral androcarpel organ (ACO) mutation permits high alkaloid yields in opium poppy Papaver somniferum

Isolation of a recessive aco (androcarpel organ) mutation in opium poppy Papaver somniferum, is described. The aco (aco aco) mutant plants form androcarpels in place of inner whorl stamens in their flowers. The abnormal flowers are self-fertile, as stamens in the outer whorl are normal. In aco mutant the calyx, corolla and syncarpous gynoecium are formed like in the wild type ACO plants. The androcarpel walls of aco plants synthesize and accumulate alkaloids like the main carpel walls. The aco mutation provides a means for improving carpel wall husk mass and thereby the yield of alkaloids.