• Journal of Apiculture
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• v.34 no.4
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• pp.285-293
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• 2019

The honey bee queen shows extreme polyandry and controlling the mating partners can only be possible either by artificial insemination or having remote isolated mating locations. Here we report on the German North Sea island of Heligoland. Because of its location 60 km from the mainland, the lack of a local population of honey bees, its size of just 1.4 ㎢ and suitable weather conditions during the months of May to July, it is considered an ideal location for controlled inseminations of high-quality virgin queen bees with drones deemed genetically superior to others. Methods how to rear virgin queen bees are described and information is provided on the numbers of queen bees, their supporting workers and drone bees that are taken to the island in the mating season. The bee most commonly involved in the Heligoland mating trials has become Apis mellifera carnica strain "Baltica". In one summer, for example, 80 virgin queens (belonging to beekeepers from nine different locations in northern Germany) each with about 600 worker bees plus two drone populations of around 2,000 drones were taken by ship to Heligoland. On their return to the mainland no later than 3.5 weeks after the mating exercise, the beekeepers could register a mating success rate of 80%. This information can help operation management of the new remote mating centre of Weedo Island, Jeonbuk in Korea, which is currently under construction.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.88.1-88.1
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• 2007

See Full Text

• Journal of Plant Biology
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• v.39 no.3
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• pp.223-229
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• 1996

The genetic variation in Korean evening primorse (Oeothera odorata L.) populations was examiend to estimate the level of allozyme variation within populatons using starch gel electrophoresis. 7 of 13 loci (Adh, Est-1, Est-2, Mdh-2, Pgd-2, Pgm-1, and Idh) revealed (Ps=43.2%) were polymorphic. The mean number of alleles per locus (A) and polymorphic locus (Ap) for populations were 1.64 and 2.46, respectively. The effective number of alleles (Aep) within populations relatively was low ranging from 1.08 to 1.22 with a mean of 1.14. Within populations, the mean number of allele per polymorphic loci (Ap) was 2.46, the mean number of alleles per locus (A) was 1.64, and the mean genetic diversity was 0.093. About 2.7% of the total allozyme diversity resided among populations (Mean GST=0.0274). FIS, a measure of the deviation from random mating within 13 populations, was relative low (mean FIS=0.03636). The indirect estimate of gene flow, based on the mean GST, was high (Nm=8.88). Estimates of gene flow were consistent with low levels of genetic differentiation among populations.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.92-98
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• 1994

Phytophthora infestans populations collected from various geographical locations of Korea in 1991 and 1993 were analyzed for mating types and responses to metalaxyl. Both A1 and A2 mating type isolates were detected in 1991. The majority of the isolates were A2 mating type, but no A1 mating type was detected in 1993. About 40% of the isolates collected in 1991 were resistant to metalaxyl, and the distribution of metalaxyl-resistant isolates of P. infestans was strongly associated with their geographic origins in Korea. Metalaxyl-resistant isolates with EC50 values > 50$\mu\textrm{g}$/ml were collected from the northern provinces of Kangwon, Kyungbuk, and Chonbuk, but not from the southern provinces of Kyungnam, Chonnam, and Jeju in 1991. The drastic increase in the degree of quantitative resistance to metalaxyl was detected among the isolates from the southern provinces during 1991~1993. More than 50% of the isolates collected from the southern provinces of Kyungnam and Chonnam in 1993 had EC50 values >50$\mu\textrm{g}$/ml. The province of Kangwon had isolates with the greatest resistance to metalaxyl. this alpine areas might be the origin of metalaxyl-resistant isolates of P. infestans in Korea. The A2 genotype with metalaxyl resistance appears to be displacing the A1 genotype which is presently the predominant genotype in Korea.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.301-312
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• 2019

Sorghum is the fifth most important cereal worldwide, spreading from Africa throughout the world. It is particularly important in the semi-arid tropics due to its drought tolerance, and when cultivated in Southeast Asia commonly occurs as a second crop during the dry season. We recovered Fusarium from sorghum in Thailand and found F. proliferatum, F. thapsinum and F. verticillioides most frequently, and intermittent isolates of F. sacchari and F. beomiforme. The relatively high frequencies of F. proliferatum and F. verticillioides, suggest mycotoxin contamination, particularly fumonisins and moniliformin, should be evaluated. Genetic variation within the three commonly recovered species was characterized with vegetative compatibility, mating type, Amplified Fragment Length Polymorphisms (AFLPs), and female fertility. Effective population number ($N_e$) was highest for F. verticillioides and lowest for F. thapsinum with values based on mating type allele frequencies higher than those based on female fertility. Based on AFLP genetic variation, the F. thapsinum populations were the most closely related, the F. verticillioides populations were the most distantly related, and the F. proliferatum populations were in an intermediate position. The genetic variation observed could result if F. thapsinum is introduced primarily with seed, while F. proliferatum and F. verticillioides could arrive with seed or be carried over from previous crops, e.g., rice or maize, which sorghum is following. Confirmation of species transmission patterns is needed to understand the agricultural systems in which sorghum is grown in Southeast Asia, which are quite different from the systems found in Africa, Australia, India and the Americas.

• Animal cells and systems
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• v.1 no.4
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• pp.535-538
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• 1997

Allozyme variation of seven enzyme systems was analyzed from 202 individuals from four Korean populations of Atractomorpha lata. These populations exhibit higher levels of values of in most other insects with a mean 64% of polymorphic loci and a mean 0.384 of expected heterozygosity within populations. Fixation indices indicated considerable substructuring within populations sampled (mean $F_{is}=0.403)$, indicating probable inbreeding or assortative mating coupled with restricted migration between subpopulations. This was supported by the field observation that the species exists as small, discrete colonies in meadow habitats and females carry males. In addition, significant differences in allere frequencies between males and females at polymorphic loci examined (70%, 16 of 23 cases) could account for the observed heterozygote deficiencies.

• Journal of Plant Biology
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• v.38 no.4
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• pp.329-336
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• 1995

Raphanus sativus L. var. hortensis f. raphanistroides (wild radish: Brassicaceae), a herbaceous perennial, occurs only on beaches in East Asia. Genetic diversity and population structure of seven Korean populations were investigated using starch gel electrophoresis. Although the Korean populatins are small, isolated with patchy distribution, the population maintain a moderate level of genetic diversity; the mean percentage fo polymorphic loci was 51.4%, mean number of alleles per locus was 1.84, and mean expected heterozygosity was 0.116. A combination of animal-outcrossing breeding system, wide geographical distribution, restricted ecological distribution, and a propensity for high fecundity may in part be explanatory factors contributing the moderate level of genetic diversity within populations. An overall excess of homozygotes relative to Hardy-Weinberg expetations (mean FISa=0.116) indicates that consanguineous mating occur within wild radish populations, leading to a family structure within a circumscribed area. Although population of wild radish experience a limited gene flow, only 5% of the total genetic variation found in Korean wild radish populations examined is due to differences among populations (mean GST=0.052). This value is considerably lower than the mean values of species with similar life history and ecological characteristics. However, significant differences were found in allele frequencies between populations for all polymorphic loci (P<0.01). It is supposed that directional selection toward genetic uniformity (similar gene frequencies) in a relatively homogenous habitat is thought to be operated among Korean wild radish populations.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.294.1-294
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• 1999

No Abstract, See Full Text

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.33-37
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• 2005

Sasa borealis Makino is distributed in East Asia such as Korea, Fushun in China, and Japan. Especially the species is only found in the high altitude (above 600 m) at mountain of cold regions including The Korean Peninsula. The level of genetic diversity and population structure of this species was surveyed using starch gel electrophoresis at putative five enzyme loci from three natural populations in Korea. Results from twelve loci indicated that genetic diversity was low. In addition, analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and loci. The reasons for the deficit of heterozygosity may be partly considered inbreeding, small population sizes, and mating of demes. S. borealis can reproduce extensively by producing rhizomes and potentially by sexually produced seeds. Rhizomes are generally long, prostate stems rooting at the nodes.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1805-1811
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• 2007

A simulation study was conducted to evaluate the effect of reciprocal cross on the detection and characterization of parent-of-origin (POE) QTL in $F_2$ QTL populations. Data were simulated under two different mating designs. In the one-way cross design, six $F_0$ grand sires of one breed and 30 $F_0$ grand dams of another breed generated 10 $F_1$ offspring per dam. Sixteen $F_1$ sires and 64 $F_1$ dams were randomly chosen to produce a total of 640 $F_2$ offspring. In the reciprocal design, three $F_0$ grand sires of A breed and 15 $F_0$ grand dams of B breed were mated to generate 10 $F_1$ offspring per dam. Eight $F_1$ sires and 32 $F_1$ dams were randomly chosen to produce 10 $F_2$ offspring per $F_1$ dam, totaling 320 $F_2$ offspring. Another mating set comprised three $F_0$ grand sires of B breed and 15 $F_0$ grand dams of A breed to produce the same number of $F_1$ and $F_2$ offspring. A chromosome of 100 cM was simulated with large, medium or small QTL with fixed or different allele frequencies in parental breeds. A series of tests between Mendelian and POE models were applied to characterize QTL as Mendelian, paternal, maternal or partial expression QTL. The overall detection powers were similar between the two mating designs. However, the proportions of paternally expressed QTL that were declared as paternal QTL type were greater in the reciprocal cross design than in the one-way cross, and vice versa for Mendelian QTL. When QTL alleles were segregating in parental breeds, a significant proportion of Mendelian QTL were spuriously declared POE QTL, suggesting that care must be taken to characterize imprinting QTL in a QTL mapping population with a small number of $F_1$ parents.