PLANT-REGENERATION AND MICROPROPAGATION OF BRACHYPODIUM DISTACHYON

Brachypodium distachyon (L.) P Beauv, has several features of its genome and growth habit reminiscent of Arabidopsis thaliana (L.) Heyn, that may allow it to be developed as a model molecular genetic system representative of the temperate grasses. In order for B, distachyon to be exploited in this way, it will be necessary to develop tissue culture procedures. This report details initial studies of the characteristics of mature seed-derived callus and the production of fertile plants from callus of three ecotypes of B. distachyon. Optimum development of embryogenic callus occurred on LS (Linsmaier & Skoog 1965) and N6 (Chu et al. 1975) media containing 3.0% w/v sucrose and 11.25 mu M (2.5 mg 1(-1)) 2,4-dichlorophenoxyacetic acid. Plants were recovered at a high frequency from embryogenic callus of ecotype B200 maintained on growth regulator-free N6 medium and were easy to establish in compost. A method was also developed for the in vitro clonal propagation of shoots using MS (Murashige & Skoog 1962) medium supplemented with 4 to 13 mu M (1.0 to 3.0 mg 1(-1)) benzyladenine. It was concluded that B. distachyon performed well in tissue culture and was suitable for further studies aimed at genetic transformation and its continued development as a model molecular genetic system.