Studies on Induction of Hairy Roots in some Leguminous Crops with Wild Strains of Agrobacterium Rhizogenes and their Morphogenic Response

The Susceptibilty of seven different leguminous crops such as Arachis hypogeae, Cajanus cajan, Cicer arietinum, Glycine max, Vigna aconitifolia, Vigno mungo, and Vigno radiata to three different wild type Agrobacterium rhizogenes strains- A4,LBA 9402 and 2659 were tested. The frequency and type of response varied with the plant species and the type of A. rhizogenes strain used. In the most cases, callus and haity roots were induced at the site of infection with A. rhizogenes. Hairy roots were isolated and cultured on Murashige and Skoog s basal medium supplemented with cefotaxime or carbenicillin and were maintained for five to six passages. Spontaneous development of shoots at the site of infection was obtained in Cicer arietinum, C. cajan and Vigno mungo using some of the A. rhizogenes strains. Hairy roots of A. hypogeae, G. max, V. aconitifolia, V. radiate were tested for shoot regeneration on media supplemented with high concentrations of cytokinins such as benzaldehyde, 6 -dimethyallylaminopurine, kinetin or thidiazuron. Shoot primordial were initiated in V. aconitifolia but they did not develop further while hairy roots of other species did not differentiate shoots. The present study demonstrate that it is possible to induce hairy roots using A. rhizogenes and to obtain spontaneous shoot differentiation in some of the legumes.