• Korean journal of applied entomology
• /
• v.35 no.2
• /
• pp.159-163
• /
• 1996

The profenofos-resistant P-Pro strain of house fly (Muscn domestica L.) was derived from the pyraclofos-resistant strain by selecting with profenofos for 7 generations. The resistance was shown to be incompletely dominant by the reciprocal crosses between the resistant and susceptible strains. Linkage group analysis for the dominant factor responsible for this resistance was carried out by the F, male-backcross method, using susceptible multi-chromosomal marker strain. The major factors for profenofos resistance were located on the second and the fifth chromosome and the other chromosomes had a little effect on the development of this resistance. The male determining factor (M) was linked to the third chromosome in this strain.

• Korean journal of applied entomology
• /
• v.34 no.1
• /
• pp.61-64
• /
• 1995

Stability of resistance of the two-spotted spider mite (Tetranychus urticae) to dicofol was investigated. Resistance level (23.0-fold) of adult females to dicofol was kept up to 1 year without selection by dicofol, but was decreased to 15.8-, 10.7-fold after 2 and 3 years, respectively. Susceptibility of adult females obtained from reciprocal crosses $(R_{female}\timesS_{male},R_{male}\times S_{female})$ of the R and S stains to dicofol was declined by the success of generation.

• Journal of Life Science
• /
• v.21 no.9
• /
• pp.1281-1287
• /
• 2011

Phyllostachys consists of high and fast growing trees and is a genus in the family Gramineae. The genus has many species in Asia, with main distribution being in India and China. One of the most popular sequences for phylogenetic inference at the generic and infrageneric levels in plants is the internal transcribed spacer (ITS) region of the 18S-5.8S-26S nuclear ribosomal cistron. We evaluated four taxa with the ITS region to estimate phenotypic relationships within the genus Phyllostachys in Korea. Alignment of the DNA sequences required the addition of numerous gaps. Sequence variation within the Phyllostachys was mostly due to natural selection, although several indels and inserts were found. Within the genus Phyllostachys, P. nigra and P. nigra var. henonis were the relatives in the three phylogenetic analyses (MP, ML, and NJ). However, some external nodes were poorly supported. Morphological traits and simple repeats (ISSR) represented the result of a relationship similar to the that of ITS sequences in the genus Phyllostachys. This suggests that ITS sequences are very informative for identification of these taxa.

• Korean journal of applied entomology
• /
• v.55 no.4
• /
• pp.413-419
• /
• 2016

Ryanodine receptors (RyRs) regulate the contractions of insect muscles by altering intracellular $Ca^{2+}$ concentration and are the targets of chlorantraniliprole. Recently, a chlorantraniliprole-resistant strain was reported in the diamondback moth Plutella xylostella by obtaining point mutations on the RyRs. In the present study, we established two resistant strains from Drosophila melanogaster, which were treated with low or high concentrations of chlorantraniliprole, and their resistance levels were determined on the basis of contact and ingestion toxicities. Compared with the control strain, the two resistant strains did not show any significant differences in contact toxicity. However, they showed significantly increased resistance ratios in ingestion toxicity than that by the control strain. The low and high concentration resistant strains exhibited 2.1- and 8.1-fold increased resistance ratios, respectively, compared with that by the control strain. Moreover, we found that the resistant strains had altered expression levels of RyRs and more enhanced Acetylcholinesterase and Glutathione-S-transferase activities than that by the non-selected strain. These results suggested that the resistance development of chlorantraniliprole in the two strains might be mediated by the activation of detoxification pathways in D. melanogaster.

• Korean journal of applied entomology
• /
• v.33 no.2
• /
• pp.74-80
• /
• 1994

The german cockroach, Blattello germanica L, populations were successively selected with dlchlowos for 11 generations. The resulting selected shin was investigated the resistance development. the cross resistance and the esterase actim@. In the dichlowos-selected(Rd) strain, the values of LCs increased 858 times more compared to the susceptible (S) strain. In the dich!o~vos-selected (Rd) strains, the cross-res~stance to chlorpyrifos, propoxur, fenvalerate and pemethnn showed 3.35. 4.09. 283 and 2.00 times. Esterase.activity of the Rd strain showed 1.33 times higher than that of the S strain in the filter paper test. In comparison of zymogram paitems of the estemse isoryme by thin agarose gel electrophoresis against the german cockroach, the S strain was separated by 4 bands uf esterase 3, 5, 6 and 8 bands and the Rd strain was separated by 6 bands of esterase 1, 2, 4, 5, 7 and 8 bands, and the resistant mechanisms of the Rd strain were considered as the 4 bands of esterase-1.2.4 and 7 bands except the common 2 bands of esterase.6 and 8 bands.

• Journal of Sericultural and Entomological Science
• /
• v.4
• /
• pp.63-68
• /
• 1965

This treatise was carried out to study the hereditary phenomenon of silk lousiness and the interaction of genes related with silk lousiness. It was also studied how to improve the silk lousiness of general raw silk by refining process because the selective process was found as unsatisfactory method. The conclusions reached were as follows. A. Conclusions related with genetic problem. 1. The decreased effects of the lousiness were 11 % in the F$_1$ hybrids. 2. Lousiness was considered to inherit as the incomplete dominance. 3. The effects of the lousiness gene were additive, and the lousiness of raw silk might be influenced by more than two genes. 4. The quantitative characters of cocoons were not genetically correlated with the occurrence of lousiness. 5. Lousiness could not be said to occur more in the heavy-cocoon strains. 6. The microscopic lousiness test of this paper showed the same result of the international exforiation test. B. Conclusions related with lousiness improvement. 1. Raw silk was able to be refined by the employment of 0.2% cationic softener solution for 30 minutes at 95$^{\circ}C$, supressing the occurrence of lousiness. 2. Anionic chemical softener was not available for silk refining process. 3. The above cationic softener refining prosess did not cause any physical defect for the silk fiber. 4. Soap refining process caused silk lousiness easily.

• Journal of Life Science
• /
• v.22 no.3
• /
• pp.285-292
• /
• 2012

Genus Spiraea is composed of many long-lived woody species that are primarily distributed throughout Asia and Europe. In this study, we evaluated a representative sample of the 38 taxa in the world, including 14 in Korea, with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. The molecular data allowed us to resolve well-supported clades in the taxa. In 47 world accessions (38 taxa: 14 Korean taxa, 33 world taxa, and 9 overlapping taxa), total alignment length was 689 positions, of which 452 were parsimony informative, 527 variable, 75 singleton, and 159 constant characters. Although the phylogenic tree showed that many taxa of genus Spiraea were well separated from each other, many branches were not congruent with the morphological characteristics and geographical distributions of the genus. There were 430 segregating sites and the nucleotide diversity (${\pi}$) value was 0.281. Under the neutral mutation hypothesis, the probability that the Tajima test statistic (D) is positive (2.325) is more than 0.5. Therefore, there may be a site at which natural selection, which increases genetic variation, is operating.

• The Korean Journal of Pesticide Science
• /
• v.2 no.2
• /
• pp.75-82
• /
• 1998

This study was conducted to find out the biochemical or metabolic resistance mechanism of brown planthopper (BPH) to carbofuran. Differences between resistant ($LD_{50};\;20.3{\mu}g/g$) and susceptible strains($LD_{50};\;0.3{\mu}g/g$) were shown. The amounts of carbofuran metabolite, benzofuranol, and the origin, not developed by Thin Layer Chromatography, were much more in the susceptible strain. But the mother compound, carbofuran, was much more in the resistant strain. The tendencies of metabolism one and three hours after treatment were similar in both strains except for the amounts of metabolites described above. From the study, it is supposed that hydrolytic enzyme, esterase, changes its role from cleaving the esteric bond of carbofuran to making conjugates with carbofuran. This seems to be the main resistance mechanism of BPH to carbofuran. Oxidase and transferase may play little or no role in resistance mechanism. Oxidative and transferring enzymes gave no effects on the metabolism of carbofuran in the resistant strain compared with the susceptible strain.

• Korean journal of applied entomology
• /
• v.33 no.4
• /
• pp.230-236
• /
• 1994

Dicofol susceptible two-spotted spider mite(S) which was selected by 150 times of dicofol treatment showed 27 5-fold increase in resistance as compared to S strain. Inheritance of resistance and crossresistance in selected strain($R_d$) were investigated. There were differences oi susceptibility in the dicofol concentmtion-moltaliity relationships between $F_1$ progenies (R♀, XS♂, R♂, XS♀) obtained from reciprocal cross with the S strain and $R_d$, strain. Degree of dominance of the $F_1$ progenies (R♀, XS♂, R♂, XS♀) were -0.29 and -0.72 in adult females and -0.42 and -0.93 in adult males, respectively. These results suggest that inheritance of dicofol resistance is controlled by an incomplete recessive. $R_d$ strain exhibited a high level of cross resistance to amitraz, and also showed cross resistance to pyrethrotd acaricides, acrinathrin and bifenthnn. $R_d$ strain showed non-cross reslstancz to abamectin, chlolfenson, clofentezine, cyhexatm, fenbutatin oxlde, fenpyroximate, hexythiazox, monocrotophos, propargite and tetradifon, but negatively correlated cross-resistance to azocyclotin and fenbutatin oxide belonging to tin acaricides.

• The Korean Journal of Pesticide Science
• /
• v.14 no.3
• /
• pp.247-254
• /
• 2010

Two-spotted spider mite, Tetranychus urticae was collected from the rose greenhouse in Chilgok, Gyeongbuk Province in December 2000. This population has been selected for ten years with bifenazate (over 450 times), and increased 855.9 fold in resistance as compared with susceptible strain (S). Cross resistance of bifenazate resistant (BR) strain to eight miticides was investigated. The BR strain exhibited high and low cross resistance to acequinocyl (614.0 fold) and to chlorfenapyr (9.1 fold), respectively. Against fenazaquin (0.3 fold) and fenpyroximate (0.1 fold), however, showed the strain negatively correlated cross resistance. Each strain collected in Choeng-ju (CJ), Kang-jin (KJ), and Chung-ju (CUJ) showed 5.5-, 964.5-, and 21.8-fold resistance to bifenazate, respectively. The detoxifying enzymes of the BR strain showed 1.6-fold activity in cytochrome $P_{450}$-dependent monooxygenase ($P_{450}$) as compared with susceptible one. By comparing the mitochondrial cytochrome b (cytb) sequence, G126S point mutation was detected in the BR and KJ strains.