AGROBACTERIUM-MEDIATED TRANSFORMATION OF COMMON BEAN

The common bean (Phaseolus vulgaris L.) is an important human dietary constituent being a rich source of protein. Genetically improved bean varieties are required as optimum yields are not realised due to constraints such as diseases and insect pests. The objective of this study was to evaluate the potential of two common bean varieties Mwitemania and Rose coco to in vitro Agrobacterium tumefaciens- mediated transformation. Mature seed embryos germinated for 1-2 days on moist filter paper, were stab inoculated with A. tumefaciens strains LBA 4404 (pBI 121), EHA 105 (pCAMBIA 1201) and EHA 105 (pCAMBIA 1301), harbouring β-glucuronidase (GUS) intron plasmids. The infected embryos were co-cultivated for 3-4 days on basal Murashige and koog,1962 medium with B5 vitamins (MSB5) or medium supplemented with 10 μM benzyl-aminopurine (BAP) and cultured on regeneration and selection medium consisting of 10 μM BAP and 50 mg L-1 kanamycin or hygromycin. Transformed shoots and roots confirmed by histochemical staining for GUS activity were obtained in 40 weeks old Mwitemania plantlets from explants infected with A. tumefaciens LBA 4404 (pBI 121). No GUS expression was observed in all Rose coco and Mwitemania shoots from explants infected with EHA 105 (pCAMBIA 1201) or EHA 105 (pCAMBIA 1301).