CULTURING PEANUT (ARACHIS-HYPOGAEA L) ZYGOTIC EMBRYOS FOR TRANSFORMATION VIA MICROPROJECTILE BOMBARDEMENT

A method for rapidly producing fertile peanut (Arachis hypogaea L.) pl ants from embryo axes was developed for use with microprojectile bomba rdment. Using this method, the apical meristem housing the germ line c ells was easily exposed for bombardment without compromising the viabi lity of the plant. Germination was rapid on MS based, hormone-free med ium containing 2% agar, while medium containing 0.6% agar caused embry o axes to swell and to develop slowly. Representatives from the market classes virginia, spanish, and runner all responded well to this proc edure, while UPL Pn4 (valencia) failed to form new leaflets. Microproj ectile bombardment did not substantially impair embryo development. Th is method circumvents chromosomal and developmental abnormalities that could potentially occur with other peanut in vitro culture systems.