The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an economically damaging pest that feeds on most thin-skinned fruits. In this study, we sequenced portions of the mitochondrial (mt) COI and ND4 genes from a total of 195 individuals collected mainly from Korea. A total of 139 haplotypes were obtained from the concatenated COI and ND4 sequences. A dataset combining GenBank sequences with our own data identified a total of 94 worldwide COI haplotypes with a maximum sequence divergence of 5.433% (32 bp). A rough estimate of genetic diversity in each country showed higher diversity in ancestral distributional ranges, but the invasion over Asian countries seems to have been substantial because haplotype diversity was only 2.35-3.97-fold lower in the USA, Canada, and Italy than that in the populations ancestral ranges.
To understand geographic genetic variation of the species and relationships among populations of the bumble bee, Bombus ardens, that is utilized as green house pollinator we expanded our investigation by sequencing somewhat longer mitochondrial DNA (mtDNA) fragment, covering some uninvestigated regions within the species distribution, and analyzing the sequence data in terms of population genetic structure. For the purpose of study, a portion of mitochondrial COI gene, corresponding to "DNA Barcode" region (658 bp) was sequenced from 160 individuals of B. ardens collected over 15 localities in Korea. The sequence data revealed overall relatively low genetic diversity within species, with a maximum sequence divergence of 0.3%. Geographically, one haplotype (BARBA01) was found in all localities surveyed, with the frequency of 91% (145 among 160 individuals), whereas other haplotypes were found in a locality mostly as a single individual, suggesting that haplotype distribution can be summarized as coexistence of widespread, one dominant haplotype and regionally restricted, other haplotypes. Overall, very high rate of per generation female migration (Nm = 4.6 ~ infinite) and very low level of geographic substitution (FST = 0 ~ 0.099) among localities were characteristic. Although some populations were genetically subdivided from the remaining localities in the hierarchical analysis, there was regional polarity on this subdivision. Taken together with gene flow estimates, the nature of genetic divergence of the bumble bee populations is characterized as one that possessing low genetic diversity, high gene flow, and wide spread of one dominant haplotype, consistent with the previous finding. To have further detailed information of this valuable genetic resource, further longer and variable molecular portion is under investigating.
The mason bee (Osmia cornifrons Radoszkowsky) is an excellent pollinator of apple. To understand geographic genetic variation of the species and relationships among populations sequenced a portion of mitochondrial COI gene, which corresponds to “DNA Barcode” region (658 bp) from 81 individuals collected over eight localities in Korea. The sequence data were used to investigate genetic diversity within populations and species, geographic variation within species, phylogeographic relationship among populations, and phylogenetic relationship among haplotypes. Summarized, overall moderate to low genetic diversity within populations and species was characteristic, concordant with the high potential to disperse of O. cornifrons in Korea. Although two populations were genetically subdivided from the remaining localities, no clear regional bias was observed. Overall, high rate of gene flow among localities and low FST was characteristic considering other relevant studies that investigated population genetic structure of other insects occurring in Korean peninsula.
To understand geographic genetic variation of the species and relationships among populations of the bumble bee, Bombus ardens, we sequenced a portion of mitochondrial COI gene, which corresponds to "DNA Barcode" region (658 bp) from 101 B. ardens individuals collected over 11 localities in Korea. The sequence data were used to investigate genetic diversity within populations and species, geographic variation within species, phylogeographic relationship among populations, and phylogenetic relationship among haplotypes. A total of nine haplortpes were found, but they very close to each other (a maximum sequence divergence of 0. 304%). Summarized, overall moderate to low genetic diversity within populations and species was characteristic, concordant with the high potential to disperse of B. ardens in Korea. There was no clear regional subdivision was observed and relatively high rate of gene flow among localities and low FST was characteristic.
Genomic DNAs (gDNAs) were isolated from the hard clam ( , Roding, 1798) populations of Gunsan located in the Yellow Sea of the Korean peninsula. Genetic distances among different individuals of the LSCP (light shell color population) population of the hard clam (lane 1-11), GSCP (grey shell color population) population of the hard clam (lane 12-22) and DSCP (dark shell color population) population of the hard clam (lane 23-33), respectively, were generated using Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, generated by seven reliable oligonucleotides primers, indicates 3 genetic clusters. LSCP population could be evidently discriminated with the other two populations among three populations. The longest genetic distance (0.801) was found to exist between individuals in the two populations, between individuals' no. 33 of the DSCP population and no. 06 of the LSCP population. The higher fragment sizes (>2,000 bp) are much more observed in the GSCP population. Three hard clam populations can be clearly distinguished, especially, by their morphological characters and PCR-based approach.
The gDNA isolated from Korean cuttle fish (Sepia esculenta Hoyle) from Sockcho (SOCKCHO), Seocheon (SEOCHEON), Incheon (INCHEON) and Vietnamese cuttle fish (VIETNAM), were amplified by PCR. Here, the seven selected primers (BION-A07, BION-A09, BION-A11, BION-A20, BION-B04, BION-B06, and BION-B14) were used to generate the unique shared loci to each population and shared loci by the four cuttle fish populations. In this study, the primer BION-A11 detected 112 shared loci by the four populations, major and/or minor fragments of sizes 300 bp, 400 bp, 700 bp and 1,000 bp, respectively, which were identical in all samples. The dendrogram obtained by the seven primers indicates five genetic clusters: cluster 1 (SOCKCHO 01-SOCKCHO 07), cluster 2 (SEOCHEON 08-SEOCHEON 10), cluster 3 (SEOCHEON 11-SEOCHEON 14), cluster 4 (INCHEON 15-INCHEON 21), and cluster 5 (VIETNAM 22-VIETNAM 28). The shortest genetic distance that displayed significant molecular differences was between individuals 25 and 26 from the Vietnamese cuttle fish (0.025), while the longest genetic distance among the twenty-eight cuttle fishes that displayed significant molecular differences was between individuals SOCKCHO no. 02 and SEOCHEON no. 12 (0.640). Individual of Seocheon and Incheon cuttle populations was somewhat closely related to that of Vietnamese cuttle fish population. Even though it could not be affirmed by a single case, such a result seems to be closely connected that the Korean peninsula is subject to climate changes by global warming. In conclusion, our PCR analyses revealed a significant genetic distance among the four cuttle fish populations.
우리나라의 대표적 향토수종인 소나무 침엽의 지리적 변이를 알아보기 위하여 남한 전 지역을 대상으로 위도와 경도를 30' 간격으로 교차되는 35집단을 선정하고 침엽을 채취하여 형태적 특성을 조사하였다. 침엽길이, 침엽폭, 기공열수, 기공밀도, 거치수, 수지구수가 집단간, 개체간에 많은 차이가 있었으며, 개체간의 차이가 집단간의 차이보다 더 컸다. 기공밀도는 남부지역의 집단들 보다는 북부지역의 집단들이 더 높았으며, 표고가 낮은 지역의 집단들 보다는 표고가 높은 지역의 집단들이 기공밀도가 더 높았다. 거치수는 북부지역의 집단들보다는 남부지역의 집단들이 더 많았으며, 표고가 높은지역의 집단들보다는 표고가 낮은 지역의 집단들이 더 많았다. 수지구 수는 해안에서 거리가 먼 내륙의 집단들 보다는 해안에서 거리가 가까운 집단들이 더 많았다. 그리고 수지구 지수는 동부지역의 집단들 보다는 서부지역의 집단들이 더 높았다. 침엽의 형태적 특성으로 유집분석 결과 3개 군으로 구분되었으며 제III군은 I, II군에 비하여 거치수는 적고, 기공 밀도가 높은 태백산맥 주위의 집단들이었다.
We investigated the variations of the flowering response to daylength in Perilla crop (var. frutescens). Seventeen accessions of Perilla crop and one accession of weedy type of var. crispa from China, Korea and Japan were cultivated under three daylength conditions, i.e., short-days, natural daylength and long-days. Most accessions of Perilla crop from China, Korea and Japan were divided into three types, early maturing type, intermediate maturing type and late maturing type by their natural flowering habit. In most of the accessions used, the flowering habit was significantly accelerated by short-day conditions and was delayed by long-day conditions. All the accessions of Perilla crops flowered within 57 days under the 10 hrs light treatment, whereas they did not flower at all even at 170 days after sowing under the 16 hrs light treatment. Thus, this finding suggested that there is a relationship between the types of flowering response to daylength and the geographical distribution which determines the planting season in traditional cultivation practices of Perilla crops. Positive correlation was observed between days to flowering and plant height or internode number in both the short-day and natural daylength conditions. Whereas, correlation was negative between days to flowering and inflorescence length or floret number in natural daylength condition, but it was positive in the short-day condition. Therefore, the daylength condition is considered as the most important environmental factor for flowering habit and morphological characters of Perilla crops. Flowering habit is considered as an important key character for the study of geographical differentiation of Perilla crop in East Asia.