• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2003.05a
• /
• pp.233-234
• /
• 2003

근교약세의 요인으로는 열성유해유전자의 호모 접합체화에 의한 적응성의 저하가 생각되어진다. 그 중에서도 가장 유해성이 높은 유전자로는 열성치사유전자가 있다. 그러나, 이러한 열성 치사유전자을 보유한 개체는 죽어버리기 때문에 직접적인 검출은 불가능하다. 따라서, 동조염색체의 호모화가 되는 교배실험과 표식유전자에 의한 연사분석이 필요하다. 본 연구는 참전복의 열성치사유전자의 유무을 명확히 파악하기 위하여 형매교배와 비형매교배을 포함한 전체교배를 하였으며, 참전복을 대상으로 개발한 마이크로사데라이트(microsatellite)좌을 유전표식으로 이용하여 각 교배구의 유전자형의 분리를 조사했다. (중략)

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

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

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.2
• /
• pp.196-200
• /
• 1987

유채박의 사료화를 위한 성분개량을 목표한 육종의 기초자료를 얻고자 유채박의 OZT함량이 낮은 영산유채와 그 함량이 고함유인 품종들을 정역교배하여 얻은 F$_2$세대의 종실을 대상으로 OZT함량에 관여하는 유전자수와 세포질의 영향에 관하여 조사분석한 결과는 다음과 같다. 1. F$_2$세대에서 OZT함양을 영산유채에 기준한 낮은 개체의 출현율은 OZT함량이 저함유인 품종을 모본으로 교배한 조합에서 높게 나타났다. 2. OZT함량의 분리비는 63 : 1에 가장 적중도가 높아 3쌍의 열성유전자가 OZT생성에 관여하고 있는 것으로 추정되었다. 3. OZT함량의 유전에 세포질의 영향이 인정되었다.

• Korean Journal of Plant Resources
• /
• v.28 no.2
• /
• pp.235-242
• /
• 2015

Morphology and characteristics of floral organ in highbush blueberry cultivars were studied to select suitable cultivars of highbush blueberry for domestic cultivation. The stamen consists an anther and a tape-like hairy filament with well-developed trichomes. When the anther was opened, the wall of anther was not dehiscent, and pollen grains were discharged into two tubes. Pollen was mature tetrad type without being separated after meiosis (Late March). The number of pollen granules per anther was 400~1,300, the germination rate was higher in the cultivars having many pollen grains. Pistil was composed of five carpels and a shipper without separate part. The number of ovules per ovary was 39~67, therefore, the coefficient of ranged from 11.6 to 31.0%. The seed pod formation by combination of ‘Bluejay’ and ‘Sharpblue’ was higher in the cross-pollination than in the self-pollination.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.291-296
• /
• 2009

This experiment was conducted to investigate the propagation system by seed to check growth, flowering, and making seed of four-year-old seedling cactus of potted Astrophytum asterias 'Nudum', A. asterias 'Super Kabuto', and A. myriostigma 'Nudum'. Plant height and width of Astrophytum asterias 'Nudum' and A. asterias 'Super Kabuto' was 5.3 to 5.5 cm, and 2.5 cm. However, plant height and width of A. myriostigma 'Nudum' was 7.6 cm and 5.6 cm as divided into 8 sections of body. In A. asterias 'Nudum', the mean seeded pod from April to September was 37.0% and the number of seeds in a pod was 43.0. In A. asterias 'Super Kabuto', the mean seeded pod from April to September was 22.5% and the number of seeds in a pod was 26.2. However, the mean seeded pod of A. myriostigma 'Nudum' from April to September was 32.3% and the number of seeds in a pod was 57.4. Especially, the seeded pod and the number of seeds in a pod of A. asterias 'Nudum' in July was the highest, 72.0% and 66.0. The sib crossing obtained much more seeded pods and the number of seeds per pod than that of selfing in the Astrophytum. The self crossing was formed from 9.0 to 20.0% of seeded pod, and 12.0 to 16.0 seeds in a pod. However, sib crossing was formed 60.0% seeded pod and 68.0 seeds in a pod on July of A. myriostigma 'Nudum'.

• Journal of Korean Society of Forest Science
• /
• v.98 no.6
• /
• pp.696-702
• /
• 2009

Yellow poplar (Liriodendron tulipifera L.) is an insect-pollinated tree species with large, perfect flower, and its seed sets average only about 10 percent naturally. In its controlled pollination, pollination bags are usually taken to prevent unwanted pollination, but bagging is an expensive and time-consuming process. Therefore, this study was conducted to determine the need of pollination bag by estimating how much unintended pollination would occur when different cross methods were applied. Five different pollination methods were applied as follows: 1) natural open pollination (i.e. insect pollination) as a reference, 2) self-pollination; no removing reproductive organs with bagging, 3) open pollination; emasculated(removing sepal, petal and stamen) without bagging, 4) controlled pollination; emasculated with bagging and 5) controlled pollination; emasculated without bagging. Very low value of full seed rate (0.2%) was observed in method 3, it was suggested that removing stamen and petal restrict the activity of pollen vectors like bee. Difference in the full seed rate between method 4 and method 5 was not significant (27.9% versus 24.0%, respectively). Consequently, controlled pollination without bagging might be an alternative method for extensive breeding and mass production of seeds in yellow poplar.

• Journal of Korean Society of Forest Science
• /
• v.104 no.4
• /
• pp.578-587
• /
• 2015

Nuclear SSR (nSSR) and chloroplast SSR (cpSSR) markers were analyzed to assess the parameters of mating system in seed orchard, such as outcrossing rates, the number of potential pollen contributors, paternal contribution rates, degree of pollen contamination, and biparental inbreeding ($t_m-t_s$). In 2006, 2007, seeds were collected from the seed orchard of Pinus densiflora, established in 1977 at Anmyeon island. Estimates of outcrossing rates ranged from 94.9 to 100% (mean 98.9%) in 2006 and from 91.2 to 100% (mean 97.7%) in 2007 on the basis of the analysis of cpSSR haplotypes and from 90.3 to 100% (mean 95.9%) in 2006 and from 81.6 to 100% (mean 95.3%) in 2007 on the basis of the analysis of nSSR genotypes. By cross checking of both DNA markers, mean cumulative outcrossing rates of 100% and 98.9% were estimated in each year. Mean contamination rates were estimated as 48.9% and 42.4%, respectively. On the basis of cpSSR haplotype observed in each seed, paternal contribution rates (the number of pollen contributors) were estimated as 0.458 (mean 16.2) in 2006 and 0.512 (mean 14.8) in 2007. In conclusion, considering pretty high level of outcrossing rates observed in a seed orchard, there might be little to be influenced by inbreeding depression for genetic potential of the seeds induced by selfing. Estimates of the mating system parameters obtained from the two reproductive years were not statistically different, which revealed stable genetic quality of seeds produced in different years. Observed results from this study may provide useful information for the management and establishment of the seed orchard of the progressive generation.

• Horticultural Science & Technology
• /
• v.16 no.2
• /
• pp.236-238
• /
• 1998

This study was conducted to investigate the effective media and optimal days after pollination for germination of seeds which were crossed by selfing or reciprocal pollination in Cymbidium spp. The elongation of ovary stopped about 110 days after pollination regardless of cross combinations. The increase of ovary width stopped about 140 days after pollination showing some differences among cross combinations. The cross combinations expressing high capsule number and viability showed good germination when they were sown in vitro. The capsules collected 150 to 180 days after pollination showed good germination performance and short days of germination. Hyponex media was the most effective for protocorm development and germination.

• Korean Journal of Ecology and Environment
• /
• v.50 no.1
• /
• pp.116-125
• /
• 2017

Alpine plants with a scarcity of pollinators in harsh environments have been believed to undergo selfing for reproductive assurance; however, contradictory evidence is also available. Snowmelt regimes in alpine areas function to change life history characteristics of alpine plants such as flowering time and duration; yet the effects of snowmelt regimes have never been tested in alpine plants in Korea. This study was conducted to investigate the dichogamy, mating systems, and flowering characteristics of Megaleranthis saniculifolia populations [early and late snowmelt plots (ESP and LSP, respectively)] in a subalpine area of Sobaeksan Mountain in Korea. M. saniculifolia exhibited incomplete protogyny in that despite early maturation of pistils, maturation times of pistils and stamens within flowers were partly overlapped. Control and hand-outcrossing treatments produced significantly higher number of follicles and seeds per flower than autonomous and hand-selfing treatments. Based on the aggregate fruit set, the auto-fertility index (AI) and self-compatibility index (SI) were 0.33 and 0.50, respectively. Snowmelt occurred 10 days earlier in ESP than in LSP, thereby ESP and LSP showed distinct differences with regard to flower longevity and season, but showing no difference in peak flowering dates. We concluded that M. saniculifolia is an incomplete protogynous and largely outcrossing plant requiring pollinator service. Temporal variation in snowmelt time and subsequent changes in flowering characteristics under climate change may further threaten the population persistence of M. saniculifolia which has already been designated as endangered species in Korea.