Production of thiophenes from callus cultures of Tagetes patula L. and its mosquito larvicidal activity.

Calli were initiated from leaf tissues of T. patula, on Murashige and Skoog's medium supplemented with 2-4 dichlorophenoxacetic acid (2,4-D) and kinetin (Kn). The maximum accumulation of biomass was recorded on 6th week at 1.11 g. dry wt/culture. Maximum thiophene content was recorded on 4th week at 0.008% on dry wt basis in callus cultures of T. patula subjected to nutrient stress. Nitrogen stress induced 3-fold increase in thiophene production level in six weeks (0.024% on dry weight basis). The best hormonal supplementation required for thiophenes production was found to be 2,4-D (2.0 mg L(-1)) and kinetin (2.0 mg L(-1)). The thiophenes produced in callus cultures of T. patula showed larvicidal effect against mosquito larvae.