Agrobacterium rhizogenes Mediated Transformation of the Forage Legumes Medicago sativa and Onobrychis viciifolia

Three cultivars of M. sativa and one cultivar of O. viciifoliawere evaluated for their response to inoculation with A. rhizogenesstrain A4T (containing pRiA4b). A cultivar-dependent responsewas observed in M. sativa with 94%, 25%, and 4% of infectedstem explants producing transformed roots in the cultivars Vertus,Regen-S, and Rangelander, respectively. In O. viciifolia cv.Hampshire Giant, an explant-dependent response was observedwith 78% and 50% of seedling cotyledon and hypocotyl explantsresponding, respectively. Leaf explants failed to produce transformedroots. Transformed roots showed plagiotropic and negativelygeotropic growth on hormone-free agar MS medium. Productionof transgenic shoots from O. viciifolia root cultures occurredspontaneously. Recovery of transgenic plants from M. salivacv. Rangelander was achieved by transfer of callus (inducedon UM medium containing 2·0mg dm^–3 2,4-D and 0·25mg dm^–3 kinetin) to MS medium containing 0·5 ingdm^–3 BAP and 0·05 mg dm^–3 NAA. Cultured rootsof both species synthesized opines (agropine and mannopine).Extensive morphological variation was observed in plants ofM. sativa (clone Al) and O. viciifolia (clone A4Tl) establishedin the glasshouse. DNA sequences homologous to TL-DNA and TR-DNAwere present in root clones and regenerated plants. Key words: Agrobacterium rhizogenes, Medicago sativa, Onobrychis viciifolia, transformed roots, transgenic plants     

Agrobacterium rhizogenes Mediated Transformation of the Wild Soybeans Glycine canescens and G. clandestine: Production of Transgenic Plants of G. canescens

Six accessions of Glycine canescens and four of G. clandestinawere evaluated for their response to inoculation with Agrobacteriumrhizogenes strain LBA 9402. The response was accession-dependent,with 9% to 70% of the seedlings producing roots following infectionof the hypocotyl. Excised cotyledons were less responsive thanhypocotyls. Roots exhibited plagiotropic and negatively geotropicgrowth in culture on hormone-free agar medium; those of G. canescensproduced shoots on B5 based medium containing 10 mg dm^–3BAP and 0.05 mg dm^–3 IBA. Cultured roots and regeneratedshoots synthesized opines. DNA sequences homologous to thoseof pRi TL and TR-DNA were present in a clonally propagated regeneratedplant of G. canescens. Key words: Agrobacterium rhizogenes, Glycine canescens, G. clandestina, transformed roots, transgenic plants