Genetics of Somatic Embryogenesis in Loblolly Pine

Clonal propagation methods must be adaptable to trees from a wide range of genetic backgrounds to meet objectives of tree improvement programs. Recently, major advances have been made in somatic embryogenesis (SE) of loblolly pine, making it a promising method for the implementation of clonal forestry for the Southeastern United States. However, initiation of SE cultures is highly variable among diverse loblolly pine families and thus it remains a bottleneck to the implementation of this technology. We investigated genetic control of SE culture initiation and naturally occurring polyembryony, using a factorial mating design. The two stages of the SE culture initiation process, i.e., extrusion of zygotic embryos and formation of somatic embryos, are both under genetic control. While initiation is primarily under additive control, extrusion is controlled both by additive and non-additive gene action (maternal and reciprocal effects). We also found that individual trees can affect initiation differently when used as mother-trees vs. as pollen parents. Our study also included an analysis of polyembryony, a naturally occurring process by which multiple embryos are formed early during development of pine seeds.

Download this file:

Download this file

Details

Author(s): John MacKay, Michael R. Becwar, Yill-Sung Park, Christina Perfetti, Juan C. Cordero

Publication: Tree Improvement and Genetics - Southern Forest Tree Improvement Conference - 2001

Section: Contribution Papers