We established a soybean banker plant system and evaluated the biological control effects of aphid control in bell pepper greenhouses. The soybean banker plant was B.communis breeding system and developed as an alternative aphid control agent to the most common Barley banker(Barley-Colemani). After inoculating approximately 50 soybean aphids(Aphis glycines, aphid starter population) on 2 week old soybean seedling pot after sowing and then releasing aphid parasitoids, an average of 348.7 parasitic wasps per a soybean banker plant could be produced without additional host aphid inoculation. Common recommendation for installation in the greenhouses are about 2 soybean banker plants per 330㎡ before or immediately after planting. If the number of aphids per stem is fewer than three on 2 weeks after installation of the banker plant, additional supplementation of 20~30 aphids is necessary to maintain this system for one month. When one soybean banker plant was installed per 120㎡, the aphid control effect was about 60% on the 21st day after installation.

Development and fecundity of the foxglove aphid, Aulacorthum solani (Hemiptera: Aphididae) were investigated at ten constant temperatures (photoperiod: 15L:9D) from 2.5 to 30℃ on soybean (Glycine max) leaves. The nymphs couldn’t emerge to adults at 2.5 and 30℃. The lower development temperature threshold and thermal constant of development completion estimated with a linear development model in nymph were 5.02℃ and 131.2 degree-days. The lethal temperatures were estimated as 33.9 and 32.5℃ with Lactin 2 and Logan 6 non-linear models, respectively. Mean generation time (from 78.4 to 11.8 d) decreased with increasing temperatures (from 7.5 to 27.5℃). The highest net reproductive rate (77.4) was observed at 20℃. The highest intrinsic rates of population increase (0.282) and shortest population doubling times (2.07 d) were recorded at 25℃.

The soybean aphid, Aphis glycines Matsumura, was introduced from East Asia (EA) into North America (NA) and is now widely established in NA. To compare soybean aphid populations between the native and invasive regions, we examined 689 individuals obtained from 28 different collections in NA and EA. A total of 8 microsatellite loci were used for population genetics statistics. Gene diversity and mean number of alleles in NA populations averaged 0.40 and 2.70, respectively, whereas in EA they averaged 0.55 and 4.32, respectively. Structure analysis of all populations revealed two distinct structures in the invaded and in the native regions. Among EA populations, certain Korean populations were genetically closest to NA populations, especially those from Ohio and Delaware. An approximate Bayesian computation test also supports an introduction into NA from Korea.

The soybean aphid, Aphis glycines Matsumura, was introduced about a decade ago from Asia into North America where it has become a serious pest of soybeans. This invasive pest has rapidly spread throughout the midwestern United States and southern Canada since 2000. We examined 689 individuals obtained from 23 different collections in USA, Korea, China and Japan for testing eight microsatellite loci. To estimate the relative likelihood of alternative introduction scenarios of the soybean aphid, an approximate Bayesian computation (ABC) was performed for microsatellite data as implemented in DIYABC. The ABC analysis tested for three scenarios (B1, B2, and B3) hypothesizing an introduction from one of the Asian countries. In this analysis, scenario B1 obtained the highest posterior probability ranging from 0.90 to 0.91 with a 95% CI of 0.81-0.99 and 0.88-0.94, which assumes an introduction from Korea. The ABC analysis revealed that one hypothetical scenario, which assumes an introduction of the soybean aphid into USA from Korea, was very robustly suggested than the other two scenarios (from China or Japan).

The soybean aphid, Aphis glycines Matsumura, was recently introduced from Asia into North America (NA) where it has become a serious pest of soybeans. This invasive pest has rapidly spread throughout the midwestern United States and southern Canada since 2000. We examined 585 individuals obtained from 23 different collections in USA, Korea, China, and Japan using eight microsatellite loci. Based on analysis of multilocus genotype, gene diversity and number of alleles in NA were averaging 0.40 and 2.70, whereas in Asia averaging 0.55 and 4.32, respectively. The factorial correspondence analysis displayed that some Korean populations were closely related to the NA populations. Structure analysis resulted in two conspicuous clusters, NA and Asia, as the most likelihood number of clusters (K). Bayesian assignment tests revealed that Osan and Milyang populations were most likely assigned to the NA populations. Bottleneck test did not show significance of genetic bottleneck in all populations. We also discuss the invasive history of the soybean aphid in light of population genetics.

Ten novel microsatellite loci were isolated and characterized from the soybean aphid, Aphis glycines. The soybean aphid was recently introduced into North America where it has become a serious pest of soybeans. This invasive pest has rapidly spread throughout the midwestern United States and southern Canada since 2000. The isolated loci were polymorphic, with two to 18 alleles in 20 individuals from a single population in Korea. The analyses revealed that 19 individuals had different multilocus genotypes, showing expected heterozygosity values ranging from 0.180 to 0.891. We report the development of microsatellite markers for A. glycines potentially suitable for further studies of population structure, dispersal, and host alternation.

The soybean aphid, Aphis glycines Matsumura 1917, is well known as a soybean pest in the world. Recently, it has been introduced to North America causing serious damage in U.S. As a cooperative research with USDA-ARS, we have investigated A. glycines in soybean fields, and also examined the colonies on the overwintering host Rhamnus davurica in order to find its natural enemies. It was generally reported that A. glycines has host alternation between the soybean, Glycine max (summer host) and the Dahurian buckthorn, Rhamnus davurica (winter host) in East Asia. However, it was very difficult to identify the soybean aphid, A. glycines, from R. davurica due to the co-existance of at least three Aphis species and the seasonal polymorphisms of each species (e.g, gynopara, ovipara, and male). For species identification, we tested 3 molecular markers, mitochondrial COI, COII, and nuclear EF1α, for 14 collected samples (7 samples from G. max and 7 samples from R. davurica). As a result, we found two different species, A. gossypii and other Aphis sp., are mixed together with A. glycines on R. davurica. We report the biology of A. glycines in Korea, and present species identification using molecular phylogenetic approach.

1987년 5월부터 9월 사이에 대전근교의 콩에 기생하고 있는 콩진딧물에서 진디벌에 기생당한 mu-mmy를 채집하여 진디벌과 중기생벌에 관한 생물학적 연구를 수행하였다. 진딧물의 진디벌에 대한 기생율, 진디벌과 중기생벌의 기주선택, mummy형성수와 형성 비율, 주요 진디벌과 중기생벌 종의 수명 등을 조사한 결과는 아래와 같다. 177개의 채집된 진딧물 mummy 중 진디벌은 27.1%m 중기생벌은 50.3%였다. Aphidius cingulatus, Ephedrus persicae, E. plagiator가 콩진딧물에 기생하고 있는 진디벌의 주요 종으로 나타났다. 그리고 이들 진디벌에 기생하고 있는 중기생벌들 중에 A. vulgaris, A. convexa가 우점으로 나타났다. 이들 중기생벌중 Charios brasicae는 한국 미기록종이었다. E.plagiator가 다른 콩진딧물에 기생하는 진디벌에 비해 중기생벌에 적게 기생되었다. 기생능력은 A. cingulatus 보다 E. plagiator가 더 높은 것으로 나타났다. 진디벌과 중기생벌의 수명은 중기생벌이 3일~29일, 진디벌은 1일~4일로 추정되었다.

Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The objective of this study was to identify the putative QTL for foxglove aphid resistance in wild soybean, PI 366121, (Glycine soja Sieb. and Zucc.). One hundred and forty one F2-derived F8 recombinant inbred lines developed from a cross of susceptible Williams 82 and resistant PI 366121, were used. The phenotyping of antibiosis and antixenosis was done through choice and no-choice assays with total plant damage (TPD) and primary infestation leaf damage (PLD); a genome-wide molecular linkage map was constructed with 504 single nucleotide polymorphism markers utilizing a GoldenGate assay. Using inclusive composite interval mapping analysis for foxglove aphid resistance, one major candidate QTL on chromosome 7 and 3 minor QTL regions on chromosome 3, 6 and 18 were identified. The major QTL on chromosome 7 showed both antixenosis and antibiosis resistance responses. However, the minor QTLs showed only antixenosis resistance response. The major QTL mapped to a different chromosome than the previously identified foxglove aphid resistance QTL, Raso1, from the cultivar Adams. Also, the responses to the Korea biotype foxglove aphid were different for Raso1, and the gene from PI 366121 against the Korea biotype foxglove aphid were different. Thus the foxglove aphid resistance gene from PI 366121 was determined to be an independent gene to Raso1 and designated to Raso2. This result could be useful in breeding for new foxglove aphid resistant soybean cultivars.

Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The foxglove aphid resistance gene, Raso2 was previously mapped from PI 366121 (Glycine soja Sieb. and Zucc.) to a 26cM marker interval on soybean chromosome 7. The development of additional genetic markers, which are mapped closer to Raso2 were required to accurately position the gene to improve the effectiveness of marker assisted selection. The objective of this study was to narrow down the putative QTL region, which is responsible to foxglove aphid resistance in PI366121 using recently developed high-density 180K Axiom SoyaSNP genotyping array. One hundred and forty one F8-derived F12 recombinant inbred lines developed from a cross of susceptible Williams 82 and resistant PI 366121, were used to generate a fine map of Raso2 interval. The phenotyping of antibiosis and antixenosis was done through choice and no-choice assays with total plant damage (TPD) and primary infestation leaf damage (PLD). The composite interval mapping analysis showed that the physical interval between two flanking makers, which was corresponding to Raso2, was narrowed down to 500kb on the Williams 82 genome assembly (Glyma2.0), instead of 4Mb in the previous report using Goldengate assay. In the Raso2 interval, there are about 60 candidate genes, including 4 of NBS-containing putative R genes. This result could be useful in breeding for new foxglove aphid resistant soybean cultivars.

Native of soybean aphid (Aphis glycines Matsumura) is an Asia and aphid is one of the dangerous pests in soybean [Glycine max (L.) Merr.]. High density aphid populations can reduce crop production by causing severe damage. The objective of this study was evaluation of resistance to the soybean aphid in soybean cultivars and germplasms. A total of fifty five soybean cultivars or germplasms, including two susceptible and two resistant check varieties, were infested to evaluate their resistance in the field cage and greenhouse test by aphid colonies which derived from wild collected one soybean aphid biotype in Korea. The average number of reproduced soybean aphid was evaluated with 62.7 aphids in the resistant check variety PI 567598B and also estimated with 1,807 aphids for susceptible check variety Williams 82. In soybean varieties and germplasms, the average reproduced soybean aphid populations ranged from the lowest 497 aphids for Junjeori to the highest 3,862 aphids for Mansu. About seventy six percent of soybean cultivars and germplasms were shown high density soybean aphid populations when compared with another susceptible check variety PI 567543C in the field cage test. From the greenhouse test to evaluate aphid index, 87.3% of soybean cultivars or germplasms presented aphid index with 9.0. No soybean cultivars and germplasms were observed with soybean resistant phenotype when regarded a aphid resistant level as less than 10% aphid reproductions compared with susceptible check Williams 82. Although no Korean soybean cultivars were identified with resistant trait to the soybean aphid, we found one great resistant genetic resource PI 567598B in this study. This result will be helpful to further study for providing useful genetic information for soybean researchers.