Genetic improvement of Papaver bracteatum: heritability and selection response of thebaine and Seed Yields.

The heritability and repeatability of various characters affecting thebaine and seed yields in Papaver bracteatum were estimated from parents and progeny families during two consecutive years of growth. Thebaine and seed yields per plant showed the lowest heritability and therefore low selection response. High selection responses were obtained for thebaine content of the capsules and mean weight per capsule, and are therefore the most appropriate criteria for increasing the thebaine yield per plant or per unit area. Similarly seed yield per capsule is more advantageous as a selection criterion for increasing the yield of seeds.