Abstract

A little leaf disease was recorded in plantations of Eucalyptus tereticornis and E. grandis at many localities in Kerala. The possibility of the association of mycoplasma like organisms (MLOs) with this disease was investigated in detail. General anatomical studies indicated necrosis and excessive formation of phloem in diseased plants. Diseased pholem tissues showed positive reaction to Dienes stain in the form of dark blue spots while fluorochrome, aniline blue gave bright fluorescent spots. However, Hoechst 33258, a DNA binding fluorochrome gave negative reaction. Disease could not be transmitted either through grafting or dodder. Tetracycline infusion in affected trees gave temporary remission of the disease symptoms. In transmission electron microscopy MLOs were found in the phloem of the diseased tissue. The present study has confirmed the association of MLOs with the little leaf disease of eucalypts