Autotoxic effects of Lycopersicon esculentum

We studied the autotoxic effects of tomato on germination, seedling growth, biophysical and biochemical parameters of plants grown in hydroponic culture. The root, stem and leaf leachates of tomato had varying effects on various parameters. The germination was stimulated by higher concentration of root and leaf leachates. The moderate concentration of root leachates inhibited the germination than lower and higher concentrations. The higher concentration of leachates stimulated the radicle growth, while, lower concentration inhibited it but the reverse was true in plumule growth. The chlorophyll a, chlorophyll b and total chlorophyll contents were decreased with increasing concentration of leachates. The inhibition of chlorophyll synthesis was concentration dependent with maximum inhibition in leaf leachate. The protein content was decreased to minimum level by root and stem leachates. Superoxide dismutase and peroxidase activity was inhibited but catalase activity was stimulated. The leachates adversely affected the biophysical and biochemical parameters resulting in arrested growth and low yield of tomato. The influence of leachates on growth followed the order was root > stem > leaf.