Loblolly pine (Pinus taeda) female gametophyte and embryo pH changes during seed development

Stage-specific measurements of female gametophyte (FG) and embryo pH (hydrogen ion concentration) were made through the sequence of loblolly pine (Pinus taeda L.) seed development. The FG tissue from two open-pollinated trees showed similar pH profiles starting at 5.5 shortly after fertilization, increasing to about 6.1 at stage 7, levelling off at 6.3–6.5 towards the end of development and dropping to 6.0 just before cone opening. Measurements...