IN-VITRO CULTURE OF GINKGO

Ginkgo biloba L. is an important landscape tree, is resistant to insec t, fungi and other pests, and produces a number of chemicals that have pharmaceutical properties (termed ginkgolides). Studies were initiate d to establish an in vitro culture protocol for Ginkgo. Explants (inta ct embryos, embryos with cotyledons removed, and cotyledon tissue) wer e removed from disinfested seeds and cultured on Murashige and Skoog m inimal organics medium with various combinations of either 2,4-dichlor ophenoxyacetic acid (2,4-D) or naphthaleneacetic acid (NAA) and either kinetin or benzyladenine (BA). Cultures were incubated in the light a nd morphological development was recorded. Both embryo and cotyledon e xplants produced callus (cotyledon tissue produced the most callus). G inkgolides A and B were detected in callus tissue extracts. Intact emb ryo cultures initiated on media with 2,4-D plus NAA for 5 wk produced shoots and roots when transferred to media with 4.5 mu M 2,4-D alone f or an additional 5 wk. Plants were transferred from the 2,4-D media to pots and maintained in the greenhouse.