INCREASING CONCENTRATION OF GROWTH REGULATOR DURING DEVELOPMENT OF SOMATIC EMBRYOS

摘要

The invention comprises methods for producing mature desiccated and desiccation-tolerant somatic embryos, particularly conifer embryos. The methods include the application of a growth-promoting hormone such as abscisic acid (ABA) to the immature embryos during development. The embryos are also water stressed during development. The concentration of the ABA undergoes a net increase relative to its initial concentration to reach a peak prior to discontinuing ABA treatment when the embryos have attained a moisture content of between 32 and 55%. The water stressing may remain constant or may undergo a net increase in intensity over the period of time during which it is applied to the embryos. The method may optionally include the further water stressing of the mature embryos to further reduce moisture contents of the embryos preferably to the level at which the embryos are tolerant of freezer storage.