Effects of Antibiotics on Inhibition of Agrobacterium tumefaciens and Differentiation of Leaf Stems from Brassica juncea Study on preparation of silver nanoparticles by biomass reduction of traditional Chinese medicinal materials and their antibacterial activity Effects of Chinese Herbal Medicines Extracts on Inhibition of Agrobacterium tumefaciens,Growth and Differentiation of Calli from Lolium perenne