Glomus fasciculatum alleviates transplantation shock of micropropagated Sesbania sesban

Investigations were carried out using the vesicular arbuscular mycorrhizal fungus, Glomus fasciculatum, to improve the success in transplanting micropropagated plantlets of Sesbania sesban. Plantlets were developed from somatic embryos and/or adventitious buds (induced from various explants on Gamborg's medium supplemented with 6-benzylaminopurine), in the presence of 10^-7 M α-naphthaleneacetic acid and 5×10^-6 M gibberellic acid. Subsequent to nodulating the roots with Rhizobium, plantlets were transplanted into sterile garden soil and inoculated with or without G. fasciculatum. Only 30% of plantlets transferred to soil without G. fasciculatum survived. In contrast, all the plantlets inoculated with G. fasciculatum survived. Histochemical study revealed the presence of intracellular hyphae with well-developed arbuscules and intercellular hyphae with vesicles, suggesting that G. fasciculatum formed a good mycorrhizal association with S. sesban roots. These observations showed that mycorrhizal association helped to increase the potential of micropropagated plantlets to successfully withstand transplantation shock.