Neotropical Entomology (2005) 34, 433-450

Alberto L. Marsaro Júnior, Sonia M.N. Lazzari, Edson L.Z. Figueira and Elisa Y. Hirooka (2005)
Inibidores de amilase em híbridos de milho como fator de resistência a Sitophilus zeamais (Coleoptera: Curculionidae)
[Amylase inhibitors in corn hybrids as a resistance factor to Sitophilus zeamais (Coleoptera: Curculionidae)]
Neotropical Entomology 34 (3), 433-450
Abstract: Sitophilus zeamais Motschulsky is one of the major pests of stored corn and it is mainly controlled by insecticides. However, due to the undesirable consequences of chemicals on the environment and human health other control measures have been investigated, especially the development of resistant plants. The presence of amylase inhibitors in corn kernels may interfere with the insect digestive process. This research was developed in order to evaluate resistance of corn hybrids to the attack of S. zeamais correlated with amylase inhibitors and nutritional composition of corn kernels. Adults of the maize weevil were exposed to grain samples of different corn hybrids at 27 ± 1°C and 75 ± 5% R.H. Biology, susceptibility index and grain consumption were evaluated. The results were correlated to the grain components (moisture content, ashes, lipids, proteins and carbohydrates) and with the amylase inhibitor activity. The amylase inhibitor activity was determined by incubating the amylase inhibitor with 0.2 units of amylase for 30 min at 25°C, and measuring the residual amylase activity determined by the iodine method. From the nutritional parameters evaluated, only the lipid content correlated significantly with the susceptibility index (r = 0.46). The amylase inhibitors obtained by the extraction with either ethanol or buffer were significantly and negatively correlated with the susceptibility index (r = -0.58), indicating that the inhibitors contribute to the resistance of corn hybrids to the attack of S. zeamais.
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(original language: Portuguese)
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Database assignments for author(s): Sonia M.N. Lazzari

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sitophilus zeamais	Stored grain