Heterosis and Combining Ability in Opium Poppy

The degree of heterosis and nature of combining ability in opium poppy were studied in a set of diallel crosses of five varieties selected from the various parts of the country. Heterosis was significantly marked for capsule number and opium yield. But a poor percentage of heterosis was shown by the different hybrids in case of morphine percentage. Both g.c.a. and s.c.a. variances were significant for all the characters indicating the importance of both additive and non-additive gene action. It was evident from g.c.a. effects of parents and s.c.a. effects of crosses that both capsule number and opium yield can be improved through heterosis breeding. The predominance of additive component for capsule weight indicated that this character can be improved through the isolation of desirable recombinants. At present it is difficult to suggest as to how a true breeding high morphine line can be produced.