Manoj Tiwarj
Abstract
Toxicity of nickel (Ni) on photosynthetic mechanisms in VAM (Gloms sp.) inoculated D. sissoo was studied at three levels each of Nickel (Ni), viz. 0.0 (Nil), 5.0 (Ni2), 50.0 (Ni3) uM and Phosphorus (P), viz. 0.0 (P1), 0.5 (P2), 2.0 (P3) in sand culture. The specific site of Ni toxicity in photosynthetic mechanism appears to be chlorophyll b. P and VAM also reduced it. Ni and P had negative and VAM positive effect on photosynthetic AT12P synthesis. Photosynthetic 14CO2 fixation was positively affected by VAM only. Reduction in chlorophyll b content and photosynthetic AT"P did not parallel with the rate of photosynthetic 14CO2 fixation in this study. Mvcorrhizal plants had higher photosynthetic rate than non-mycorrhizal ones.