• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.311-315
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• 2004

The brown planthopper, Nilaparvata lugens, is among the most serious insect pests of rice. It is widely distributed in Asia, Australia and Pacific islands. An earlier mitochondrial DNA study revealed that there exist significant genetic differences between populations north and south of the Red River Delta region in Vietnam. However the mitochondrial DNA was not sufficiently variable to examine the sources of immigration. For a more detailed analysis of geographic population structure of N. lugens, we developed microsatellite markers. Thirty-seven putative microsatellite loci were isolated using a magnetic biotin method, and five primer pairs designed from the flanking regions of sequenced microsatellite clones were labeled with fluorescent. Of these five primer sets, two have proven to be useful across all the samples we used in this study. We used variation at these two microsatellite loci to test the hypothesis that N. lugens biotypes (1, 2, and 3) sampled from laboratory selection constituted distinct genetic units. Allele frequency differences among the three major biotype categories were not significantly different at one locus (27035). However, the other (7314) did show differences among the major three biotypes. The methods we describe here will be useful for studying population structure of crop pest and for tracking the patterns of migratory pest like the rice planthoppers.

• Korean Journal of Plant Taxonomy
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• v.43 no.1
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• pp.12-21
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• 2013

To clarify the taxonomic position for Astragalus nakaianus and provide correct scientific name for A. mongholicus cultivar in South Korea, we examined external morphological characters and sequence variations from ITS and five cp non-coding DNA regions. Genetic structure was also analyzed for 61 individuals from three populations using nine microsatellite loci. We found no significant difference between the South Korean cultivar and A. mongholicus var. dahuricus when morphology and ITS sequences were considered. Morphologically, A. nakaianus specimens varied somewhat from A. mongholicus var. mongholicus and var. dahuricus in habit, plant height, and lengths of leaf axis and leaflet. Although sequence data from ITS and cp noncoding DNA regions could not distinguished A. nakaianus from A. mongholicus, microsatellite analysis revealed strong structuring between the cultivar and A. nakaianus. Therefore, we conclude that the South Korean A. mongholicus cultivar should be treated as A. mongholicus var. dahuricus and that A. nakaianus should be merged into A. mongholicus as a variety, i.e., A. mongholicus var. nakaianus.