Influence of VAM inoculation on root colonization, survival, physiological and biochemical characteristics of chrysanthemum plantlets

Experiment was conducted to study the effect of inoculation of vesicular arbuscular mycorrhizal (VAM) fungi on physiological and biochemical characteristics of in vitro raised plantlets of chrysanthemum variety Yellow Bangla. Different soil based microbial inocula were used by laying 20g culture below the roots of in vitro raised plantlets. The strains used were Acaulospora laevis, Acaulospora sccrbiculata, Glomus fasciculatum and mixed AMF strain (IARI). Microbial inoculation significantly improved root colonization, survival percentage, physiological and biochemical characteristics over control. Relative water content was significantly enhanced by microbial inoculation. Mixed AMF strain gave the maximum root colonization and survival percentage of plantlets. Glomus fasciculatum was found most effective to improve relative water content of leaves. Highest photosynthetic rate was observed in mixed AMF inoculated plants followed by Acaulospora laevis inoculated plants. Acaulospora laevis inoculated plantlets showed maximum stomatal resistance and internal CO₂ content followed by mixed AMF inoculated plantlets. Chlorophylls and carbohydrates and sugar concentration increased in tissue cultured plantlets inoculated with Acaulospora laevis. Reducing sugar concentration increased maximum in mixed AMF associated plantlets. However, non reducing and total sugar concentrations were maximum in Acaulospora laevis inoculated plants. Mixed AMF strain and Acaulospora laevis performed well in improving physiological and biochemical characteristics of tissue culture raised plantlets.