Abstract:
Plant parasitic nematodes can directly or indirectly damage all kinds of crops in the world and cause serious economic losses. In this study, twenty-seven bis-heterocyclic ketones that have not been reported were designed and synthesized, and their lethal activity
in vitro against
Meloidogyne incognita and their inhibition rates
in vivo caused by
M. incognita in sand and matrix soil were measured. Results of the test
in vitro showed that most of the compounds had no activity against
M. incognita at 40 mg/L for 72 h, except for compounds
D1 and
E3 , which showed 70.03% and 71.26% mortality, respectively. Results of the test
in vivo showed that the inhibition rates of compounds
B1 ,
B2 ,
B5 ,
C4 ,
D2 ,
E6 and
E9 in sand were higher than 90% against
M. incognita at 40 mg/L, and the inhibition rate of
D2 reached 87.61% at 5 mg/L, which was the highest one and higher than that of lead compound
B1 . In matrix soil, the inhibitory activity of compound
B5 was the strongest, and the inhibition rate was 77.67% at 40 mg/L. Preliminary analysis on the structure-activity relationship demonstrated that (5-(2-thienyl)-2-thiazolyl)-2-thienylmethanone(
D2 ) without any substituents on the 2-thiophene ring had better nematicidal activity.