Biochemical studies on malathion resistance,inheritance and association of carboxylesterase activity in brown planthopper,Nilaparvata lugens complex in Peninsular Malaysia |
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Authors: | M A Latif Mohd Yosuh Omar Soon Guan Tan SS Siraj Abdul Rahim Ismail |
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Institution: | 1. Department of Crop Science, Faculty of Agriculture;2. Department of Biology, Faculty of Science;3. Department of Cell and Molecular Biology, Faculty of Biotechnology and Molecular Science;4. Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor, Malaysia |
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Abstract: | Abstract Two sympatric populations of brown planthopper (BPH), one from rice and the other from Leersia hexandra were collected from each of five locations in Malaysia. All the tested malathion-resistant individuals of the rice BPH population and F1 generation (cross between malathion-resistant usually caught on rice] and malathion-susceptible usually caught on Leersia]) showed high esterase activity, while all malathion-susceptible individuals on L. hexandra showed low esterase activity. In the F2 generation, all the individuals tested against malathion were approximately 75% resistant and 25% susceptible and the inheritance pattern of esterase activity (high and low esterase activity) segregated in the same manner to a 3: 1 ratio. This confirms that resistance to malathion is mono-factorial and inheritance pattern of esterase activity is also linked to malathion resistance. Carboxylesterase or total esterase activity in BPH is inherited in a simple Mendelian fashion that is encoded by a single dominant gene. For the total esterase assay, average esterase activity levels in the rice-infesting population ranged from 17.64 to 19.37 nmoles 1-napthol/mg protein while that in the Leersia-infesting population ranged from 5.29 to 6.11 nmoles 1-napthol/mg protein. In terms of esterase activity, the two sympatric Nilaparvata lugens populations separated into two distinct groups. Results based on the tube color intensity test showed 96% and 98% resistant and susceptible individuals were present in the rice- and Leersia-infesting populations, respectively. In a filter paper test, the rice-infesting population had 94% with high esterase activity while the Leersia-infesting population had 96% with low esterase activity. |
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Keywords: | brown planthopper carboxylesterase assay inheritance study insecticide resistance rice |
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