Production of nematocidal compounds by hairy root cultures of Tagetes patula L.

Marigold (Tagetes patula L.) hairy roots induced by infection with Agrobacterium rhizogenes produced α-terthienyl when grown in darkness, and an n-hexane extract of the roots showed nematocidal activity. Depending on the hairy root line used, the level of α-terthienyl varied from 15 to 1268 μg per g dry weight, a level that corresponded to 0.15 to 12.7-fold that in intact roots. Analysis by HPLC indicated that the nematocidal activity was due predominantly to α-terthienyl. However, it is suggested that nematocidal compounds other than α-terthienyl are present in hairy roots cultured in the dark for long periods or in the light.