Biochemical changes induced by fungicides in nitrogen fixing Nostoc sp.

ABSTRACT

The present study indicates the effect of fungicides (approved by WHO) and their behavior on nitrogen fixer of rice eco system Nostoc sp. Application of plant protecting chemicals at recommended levels braced up the growth of blue green algae thereby enhancing heterocyst formation and nitrogenase activity. Nostoc sp demoed varying degrees of sensitivity to fungicides. Biomass yield, protein, carbohydrate content reduced after 3pg/mL concentration. Heterocyst damage was observed from 4µg/mL, Proline content increased with increase in fungicide concentration, utmost yellowing of the culture started from 4µg/mL. The decreasing order of the toxicity to Nostoc sp with fungicides was Mancozeb> Ediphenphos> Carbendazim> Hexaconazole.