Z. Xing, W.A. Powell, and C.A. Maynard. State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210

In Vitro Cell. Dev. Bio. 32:70-71A. Contributed paper # P-1017. World Congress on In Vitro Biology, San Francisco, CA, June 22-27, 1996.

An ovule culture procedure has been developed to produce mature somatic embryos of American chestnut (Castanea dentata (Marsh.) Borkh.). Ovules were excised from immature burs collected from 2 American chestnut trees in Central New York 1 month after flowering. Embryogenic calli were initiated from the ovules as previously described (Merkle et al. 1991. Can. J. For. Res. 21:1698-1701). The callus-inducing medium was a modified McCown's Woody Plant Basal Medium plus 4 mg/liter 2,4-D and 0.25 mg/liter BA. Of 155 ovules cultivated, 5 produced somatic embryogenic calli after 2 months of cultivation. The calli were then transferred onto Gamborg's B-5 basal medium plus 0.5 mM BA and 0.5 mM NAA and cultivated under a 16-h photoperiod (40 micro moles/m2/sec) at 23 C for 3 months. All stages of the somatic embryo from heart-shaped through mature embryos were obtained. Secondary embryogenesis was also observed. The mature embryos germinated on half-strength Murashige and Skoog basal medium.