Authors : S. S. Bodkhe
Page Nos : 170-176
Description :
Abstract:
Cyanobacteria present abundantly in soil are important in maintaining field fertility through nitrogen fixation. In present day agricultural practices, for improving crop productivity application of agricultural pesticides has become necessary. Cyanobacteria are also affected by pesticides as non-target organism. For successful exploitation of nitrogen fixing cyanobacteria as biofertilizer, it is evident to select a tolerant strain along with understanding of their tolerance. The response of two nitrogen fixing cyanobacterial species of Nostoc to Endosulfan and Lasso was hence examined in present study. Photosynthetic pigment and nitrogen fixing capacity of two species of Nostoc, N. commune and N. linckia were recorded after 15 days of treatment with various concentration of Endosulfan and Lasso. Stimulatory and inhibitory type of responses were recorded. 10 ppm and 20 ppm concentration of Endosulfan enhanced growth in N. commune while 40ppm inhibits growth. In N. linckia all the concentration reduced growth. While all the conc. of Endosulfan inhibits nitrogen fixing capacity of both the species of Nostoc. In N. commune as well as N. linckia 10 ppm and 20 ppm of Lasso stimulated growth and at 40 ppm conc. the growth was inhibited. Nitrogen fixation was stimulated in N. commune at 10ppm concentration. In N. linckia it was stimulated at 10ppm and 20 ppm concentration. Differential response towards tolerance level of Endosulfan and Lasso was observed among species of the same genus.
Keywords: Cyanobacteria, Pesticides, Endosulfan, Lasso, Nostoc.
