Nematicidal Activities of Extracts from Leaves of Tagetes erecta

In order to study the nematicidal activities of extracts from leaves of Tagetes erecta, we detected the nematicidal activities of the ethanol extracts, alkaloids constituents, saponin constituents and α-terthienyl from leaf of T.erecta. And also, the content of α-terthienyl in the ethanol extracts of T.serecta leaves with nematicidal activities was detected. The results showed that the ethanol extracts had certain nematicidal activities, the corrected death rate for nematode was >80% at the concentration of 50 mg/mL. The results of the alkaloid extraction experiment showed that water-soluble alkaloids had the better nematicidal activities, the adjusted mortality for nematode was >50% at the concentration of 50 mg/mL. In the sapornin extraction experiment, water-soluble extracts had some nematicidal activies, the adjusted mortality for nematode was >50% at the concentration of 25 mg/mL. The flocculent saponin had the best nematicidal activities and the adjusted mortality for nematode were all of >90%.The results of nematicidal activities experiment of α-terthieny showed that the LC50 of photoactivation and non-photoactivation α-terthienyl was 312.5 μg/mL and 431.2 μg/mL, respectively. And the content of α-terthienyl in the ethanol extracts of 50 mg/mL with the corrected death rate of >80% for nematode was 1.412 μg/mL. It is suggested that water-soluble extracts from T.erecta leaves have some nematicidal activities, but the extracts with the best nematicidal activities from T.erecta leaves may be saponin.