Abstract: In one aspect, a method is provided for increasing germination vigor and/or frequency of conifer somatic embryos produced in vitro. The method comprises (a) incubating a plurality of immature conifer somatic embryos for a first incubation period in, or on, a first development media at a temperature in the range of 20° C. to 30° C.; (b) exposing the plurality of immature conifer somatic embryos incubated in accordance with step (a) to a cold temperature in the range of 0° C. to 10° C. for a time period of at least one week; and (c) incubating the plurality of immature conifer somatic embryos treated in accordance with step (b) for a second incubation period in, or on, a second development medium at a temperature in the range of 20° C. to 30° C.

Abstract: In one aspect, a method is provided for increasing germination vigor of conifer somatic embryos produced in vitro. The method comprises (a) culturing a plurality of immature conifer somatic embryos for a first incubation period in, or on, a first development medium that comprises less than 0.1% trehalose; and (b) culturing the plurality of immature conifer somatic embryos treated in accordance with step (a) for a second incubation period in, or on, a second development medium that comprises at least 0.1% trehalose.

Abstract: The invention relates to the knowledge of sugar alcohols as indicators of biochemical maturity of pine zygotic and somatic embryos. It has been discovered that loblolly pine zygotic embryos have a progression of different sugar alcohols as they approach biochemical maturity. Pinitol is the first sugar alcohol to appear in abundance. This is followed by D-chiro-inositol, and finally by fagopyritol B1. As a later appearing alcohol becomes more abundant in the embryos, the earlier ones decrease in amount present. Analysis of the embryo sugar alcohols can be helpful in determining when to harvest cones from seed orchards. Further it can be used as a guideline for formulation of more effective culture media in the propagation of somatic embryos by tissue culture. There appears to be a requirement for fagopyritol B1 if good germination of somatic embryos is to be achieved.

Abstract: The invention concerns measurement of sucrose series oligosaccharides, particularly sucrose, raffinose, and stachyose, and the dehydrin group proteins, in conifer somatic embryos as a measure of their biochemical maturity and readiness to germinate. The information gained is useful for evaluation of the effectiveness of the culture media, particularly that used for the development of the cotyledonary embryo stage. Somatic embryos having elevated levels of the oligosaccharides have been shown to have improved germination, especially those in the genus Pinus. The invention is also directed to conifer somatic embryos having elevated levels of sucrose series oligosaccharides and dehydrin group proteins.