AGROBACTERIUM RHIZOGENES-MEDIATED GENE-TRANSFER IN MUNGBEAN (VIGNA-RADIATA L. (WILCZEK))

Stable transformation and expression of transgenes,vas achieved in mun gbean using Agrobacterium rhizogenes-mediated system. Seedling hypocot yls, on cocultivation with different A. rhizogenes strains containing Ri plasmid and a binary vector (pBin9GUSint) with neomycin phosphotran sferase II and GUS (with a intron in coding region) as marker genes, p roduced roots which showed GUS expression and rapid growth on hormone free-medium containing 50 mg l(-1) kanamycin and 500 mg l(-1) cefotaxi me. Transformation frequency varied with the age of the explants, dura tion of pre-induction of explants, cocultivation time and medium, conc entration and strain of Agrobacterium but did not vary too much with d ifferent genotypes of mungbean. The transgenic roots produced calli on callusing medium containing 50 mg l(-1) kanamycin and 500 mg l(-1) ce fotaxime. The calli showed expression of nptII and Gus genes. Transfer of GUS DNA into mungbean genome was confirmed by Southern blot analys is. However, neither transgenic roots nor their calli could regenerate shoots on either the B-5 or B-5-containing different cytokinins or au xins alone or in combination.