• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.126-131
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• 1996

In this study effects of isolation distance, transplanting time of maternal plants, and bagging of flower head with the gauze-cloth bag on the outcrossing of burley tobacco (Nicotiana tabacum L.) were investigated. Also the effect of fertilizer level and control of the number of capsules per plant on seed production and quality were examined. A male sterile line. produced 0.3 to 3.8 capsules Per plant when it was Planted with normally flowering tobacco with the average outcrossing of 7.2 plants, ranging from 2 to 18 out of 20 plants. With the farther the isolation distance between maternal plants and pollen donor plant, the lower the outcrossing occurred. Outcrossing occurred even at the isolation distance of 312 m. When the maternal plants were transplanted 35 days after transplanting the pollen donor ones, the outcrossed plants were not decreased significantly. The bagging of the flower head with the gauze-cloth bas (#0.9∼ 1.0 mm) decreased the outcrossed plants significantly, but couldn't prevent the outcrossing completely. The seed amount per plant was higher in the highly fertilized cultivation. The number of seed capsules per plant affected significantly on seed yield and quality. When the seed capsules was controlled by 30 or 50 capsules per plant, the weight of 1,000 seeds and germination rate were higher than those with 70 or 90 capsules per plant. Key words : Nicotiana tabacum, outcrossing, bagging.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.411-414
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• 2006

The mating systems of two groups of natural populations of Gleditsia japonica var. koraiensis in Korea were determined using allozyme analysis. The result suggests that G. japonica var. koraiensis is predominantly outcrossing. The tm values of eight populations in Korea varied from 0.667 (Mdh-1) to 0.938 (ldh-1), giving an average 0.820. Population and individual outcrossing estimates were associated with flowering tree density or degree of spatial isolation. The reason for relatively low outcrossing rates of some populations could be attributed to reduction of effective population sizes of sib for the medicine, small population size, and isolation of flowering mature trees. The heterozygote excesses were observed in some natural populations, whereas other populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.225-229
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• 2007

The mating systems of natural populations of Potentilla freyniana in Korea were determined using allozyme analysis. The result suggests that P. freyniana is outcrossing as well as employing vegetative reproduction by stolon (self-fertilization rate, s < 0.5). The values of the inbreeding coefficient of eight populations in Korea varied from 0.244 to 0.331, with an average value of 0.274. For eight natural populations, multi-locus estimates of outcrossing (tm) was 0.603 across 13 polymorphic loci, with individual population values ranging from 0.530 to 0.652. The relatively low outcrossing rates of some populations could be attributed to extensive vegetative reproduction by stolon and the isolation of flowering mature plants. Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers. Although heterozygote excess was observed in some natural populations, most populations exhibited varying degrees of inbreeding and a heterozygote deficit.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.63-71
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• 2012

To assess parameters of mating system in seed orchard, such as outcrossing rates, number of potential pollen contributors, and degree of pollen contamination, seeds, produced in '77 plot of the Japanese red pine (Pinus densiflora S et Z) seed orchard at Anmyeon island, were collected in 2007 and analysed by nSSR and cpSSR markers. Estimates of outcrossing rates ranged from 91.2 to 100% (mean 97.7%) on the basis of the analysis of cpSSR haplotypes and from 81.6 to 100% (mean 95.3%) on the basis of the analysis of nSSR genotypes. By cross checking of both DNA markers, seeds, presumed to be products of self pollination on the basis of single marker, were confirmed as outcrossed seeds, which resulted in cumulative outcrossing rates of 98.9%. On the basis of pooled cpSSR haplotype of each seed, the number of pollen contributors and paternal contribution rates were estimated as 14.8 and 0.512, respectively. In conclusion, considering pretty high level of outcrossing rates observed in a seed orchard, good genetic potential of the seeds, produced in '77 plot of the seed orchard of Japanese red pines at Anmyeon island, may be guaranteed. Investigated results from the analysis of mating system of Japanese red pines in a '77 plot of the seed orchard may also be expected to provide useful information for the management and establishment of the seed orchard of the progressive generation.

• Journal of Life Science
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• v.17 no.11
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• pp.1477-1481
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• 2007

The mating systems of natural populations of Vicia tetrasperm in Korea were determined using allozyme analysis. The result suggests that V. tetrasperm is low rates of outcrossing or mix-mating outcrossing (self-fertilization, s < 0.5). At the population levels, the values of inbreeding coefficient of ten populations in Korea varied from 0.131 to 0.176, giving an average 0.154. For ten natural populations, multi-locus estimates of outcrossing (tm) was 0.333 across fifteen polymorphic loci, with individual population values ranging from 0.269 to 0.423. The differences between the tm and ts values were not close to zero (tm - ts > 0.154), indicating that biparental inbreeding was significant in the loci. The reason for relatively low outcrossing rates of some populations could be attributed to extensive consanguineous mating and isolation of flowering mature plants. Although heterozygote excess was observed in one natural population, most populations exhibited varying degrees of inbreeding and heterozygotes deficit. Thus, selection against homozygotes operated in the progeny populations throughout the life cycle.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.57-57
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• 2017

Chrysanthemum is one of the most important floral crop in Korea produced about 7 billion dollars (1 billion for pot and 6 billion for cutting) in 2013. However, it is difficult to breed and to do genetic study because 1) it is highly self-incompatible, 2) it is outcrossing crop having heterozygotes, and 3) commercial cultvars are hexaploid (2n = 6x = 54). Although low-density genetic map and QTL study were reported, it is not enough to apply for the marker assisted selection and other genetic studies. Therefore, we are trying to make high-density genetic mapping using GBS with about 100 $F_1s$ of C. boreale that is oHohhfd diploid (2n = 2x = 18, about 2.8Gb) instead of commercial culitvars. Since Chrysanthemum is outcrossing, two-way pseudo-testcross model would be used to construct genetic map. Also, genotype-by-sequencing (GBS) would be utilized to generate sufficient number of markers and to maximize genomic representation in a cost effective manner. Those completed sequences would be analyzed with TASSEL-GBS pipeline. In order to reduce sequence error, only first 64 sequences, which have almost zero percent error, would be incorporated in the pipeline for the analysis. In addition, to reduce errors that is common in heterozygotes crops caused by low coverage, two rare cutters (NsiI and MseI) were used to increase sequence depth. Maskov algorithm would also used to deal with missing data. Further, sparsely placed markers on the physical map would be used as anchors to overcome problems caused by low coverage. For this purpose, were generated from transcriptome of Chrysanthemum using MISA program. Among those, 10 simple sequence repeat (SSR) markers, which are evenly distributed along each chromosome and polymorphic between two parents, would be selected.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.344-352
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• 2010

To investigate the mating system of clones in the seed orchard of Japanese red pine, parameters of mating system, such as outcrossing rates, number of potential pollen contributors, and degree of pollen contamination, were estimated in the seed orchard of Japanese red pines on the basis of DNA data including 4 nSSR and 6 cpSSR markers. Estimates of outcrossing rates were ranged from 94.9 to 100% with an average of 98.9% on the basis of the analysis of cpSSR haplotypes. They were ranged from 90.3% to 100% with an average of 95.9% on the basis of the analysis of nSSR genotypes. However, cross checking of both DNA markers revealed that the seeds presumed to be products of self pollination were turned out to be generated by pollination between mother tree and other tree (i.e., 100% of cumulative outcrossing rate). Estimates of pollen contamination ranged from 43.6% (Gangwon-10) to 56.4% (Gangwon-12) with the average of 48.9%. On the basis of pooled cpSSR haplotype of each seed, maximum number of 21 pollen contributors were verified from the seeds reproduced by Kyungbuk-38. Minimum number of 13 pollen contributors were verified in Gangwon-10. Mean of 16.2 pollen contributors were verified from a total of 5 mother trees. In conclusion, considering pretty high outcrossing rates between clones within a seed orchard, it may be expected that a fairly good genetic potential of the seeds, produced in '77 plot of the seed orchard of Japanese red pines at Anmyeon island, may be guaranteed. Observed results from the analysis of mating system of Japanese red pines in a '77 plot of the seed orchard may also provide useful information for the establishment and management of the seed orchard of the progressive generation.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.264-271
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• 2013

Mating system parameters were estimated in a natural population of Pinus koraiensis which was located at Gwongeumseong in Mt. Seorak, South Korea. The estimated parameters from allozyme were as follows: 0.882 of multilocus outcrossing rates($t_m$), 0.881 of singlelocus outcrossing rates($t_s$), 0.368 of correlated paternity($r_p$), and 2.7 of number of effective pollen contributors. The estimated parameters from cpSSR markers were as follows: 0.831 of average of outcrossing rates and 12.4 of the average number of effective pollen contributors. The average outcrossing rate from two genetic markers was 0.857, which was similar to those estimated in other conifer species. More number of potential pollen contributors was estimated from cpSSR marker analysis compared with that estimated from allozyme marker analysis. This result sugges$t_s$ that cpSSR markers may be more useful than allozyme markers for identifying potential pollen contributors in the analysis of mating system.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.47-53
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• 2007

To assess the risk of genetically modified (GM) rice on the agricultural ecosystem, agronomic characteristics, pollen longevity and outcrossing rate between GM (Iksan 483 and Milyang 204) and non-GM (their wild types and female parents) varieties were investigated using the bar gene as a tracer marker in paddy field. The agronomic characteristics of two GM rice were similar to their female-parents (non-GM rice) except heading date and 1,000 grain weight of Iksan 483, and they did not show a difference by the introgression of the bar gene as the genetic traits of rice varieties. Pollen viability was more than 90% just after shedding, and it was rapidly decreased below 50% at 5 minutes after shedding both GM and non-GM varieties. The Pollen longevity was lost after 30 minutes of anthesis. When the distance of gene flow from GM to non-GM rice detected to 6 m from the edge of GM rice plant, the maximum distance of pollen dispersal was 4.5m and 3.9m in Iksan 483 and Milyang 204, respectively, and that was increased in order of west, south, east, and north to the dominant wind direction, west-south. Mean outcrossing rate was very low as 0.003 and 0.001% within 1.5 m from the edge of Iksan 483 and Milyang 204, and the GM hybrids by the pollen dispersal did not detected over 4.5 m from the edge of GM rice plant. The results may help to establish the strategy which reduce the risk of pollen-mediated gene flow between GM and non-GM rice.

• Korean Journal of Plant Resources
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• v.24 no.6
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• pp.702-711
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• 2011

Buckwheat (Fagopyrum esculentum Moench), one of the minor crops grown in Korea belonging to the Polygonaceae family, is an annual crop widely cultivated in Asia, Europe, and America and has a character of outcrossing and self-incompatibility. The objective of this study was to analyze the genetic variability, phylogenetic relationships and population structure of buckwheat landraces of Korea using SSR markers. Ten microsatellite markers have been detected from a total of 79 alleles among the 179 buckwheat accessions were collected from Korea. The number of allele per marker locus ($N_A$) ranged from 2 (GB-FE-001, GB-FE-043 and GB-FE-055) to 31 (GB-FE-035) with an average of 7.9 alleles. GB-FE-035 was the most polymorphic with the highest PIC value 0.93. Major allele frequencies ($M_{AF}$) for the 10 polymorphic loci varied from 0.12 to 0.97 with a mean allele frequency of 0.57. The expected heterozygosity ($H_E$) values ranged from 0.05 to 0.94 with an average of 0.53. The observed heterozygosity ($H_O$) ranged from 0.06 to 0.92 with an average of 0.42. The overall polymorphic information contents (PIC) values ranged from 0.05 to 0.93 with an average of 0.48. The landrace accessions of buckwheat used in the present study were not distinctly grouped according to geographic distribution. The study concludes that the results revealed genetic differentiation was low according to the geographic region because of outcrossing and self-incompatibility. We reported that our analyses on the genetic diversity of common buckwheat cultivars of Korea were performed by using of microsatellite markers.