Nematicidal activity of Lagenandra toxicaria Dalz and Kaempferia rotunda L. rhizome extracts against root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood and burrowing nematode, Radopholus similis Cobb

摘要

The plant parasitic pests such as the root-knot nematode Meloidogyne incognita and burrowing nematode, Radopholus similis are considered as devastating pathogens that are responsible for huge economic loss worldwide. The development of huge resistance, high costs and non-targeted effects of synthetic nematicides made control of these pests’extremely challenging. In this scenario the present study evaluated the nematicidal potential of the rhizome extracts of two plants viz . Lagenandra toxicaria and Kaempferia rotunda against these pests. Ethyl acetate and ethanol extracts of both plants were showing strong nematicidal properties against M. incognita and R. similis . An increase in the exposure time significantly increased the mortality of nematodes. The ethyl acetate extract of K. rotunda (KrEA) at 8 mg/mL concentration reduced the survival rate of M. incognita and R. similis to 3.57 ± 3.5 and 9.67 ± 4.27 respectively after 72 h treatment. Similarly, the ethanolic extract (KrOH) at the same concentration reduced the survival of M. incognita and R. similis to 5.36 ± 5.1 and 13.83 ± 5.38 respectively following 72 h treatment. Ethyl acetate extract (LtEA) and ethanolic extract (LtOH) of L. toxicaria at 8 mg/mL, reduced the survival rate of M. incognita to 9.37 ± 8.08 and 18.75 ± 8.19 respectively. On the contrary, water extracts of both plants were least effective against both these parasites. The LC_(50)values calculated using probit analysis highlighted the potential of ethyl acetate and ethanol extracts of both plants against M. incognita and R. similis . Based on LC_(50)values, the water extract of both plants was recorded to be less toxic against the tested nematodes.