In vitro growth of immature peach embryos as related to carbohydrate source and pH

Carbohydrate source of peach embryo culture media affects embryo growth and survival. The objective of this study was to determine the effect of five carbohydrates (fructose, glucose, maltose, sorbitol, and sucrose) at different levels and MES at two pH levels on the germination and survival of peach embryos in vitro. Use of fructose, glucose, maltose, and sucrose resulted in better embryo germination and survival than either glucose or sorbitol. Fructose (2% and 3%) produced better survival than did sucrose (2% and 3%) in smaller embryos (< 10% ovule dry weight). However, sucrose produced better survival than did fructose in the larger embryos (>10% ovule dry weight). MES at 4.5 mM was equal to 0.0 mM MES and better than 9.0 mM at promoting germination and survival of immature peach embryos in vitro culture. Although MES at 9.0 mM proved superior at stabilizing media pH before and after autoclaving, it was inferior to the 0.0 mM and 4.5 mM levels in promoting healthy embryos.