TRANSFORMATION OF TROPICAL GRAIN LEGUMES USING PARTICLE BOMBARDMENT

The particle bombardment method for direct gene transfer was used to i ntroduce beta-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) genes into three Vigna species. Relatively high frequency of trans ient GUS expression was observed on all parts of germinating embryos 1 8 to 24 hours after bombardment. Factors such as the ratio of gold par ticles to plasmid DNA carrying the genes of interest, pressure used fo r delivery of the particles into tissues, and the number of times the tissues were bombarded all affected the efficiency of transient GUS ex pression. In addition, incubation of tissues on kinetin enhanced the e xpression of GUS. These results indicate that the particle delivery sy stem could effectively be used to introduce genes into meristematic re gions of Vignas.