• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.24-30
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• 1984

The average number of empty seeds per cone on the mature tree was $10.03{\pm}0.61$. The ratios of empty seeds to total seeds and to full seeds were $7.38{\pm}0.35%$ and $8.42{\pm}0.49%$, respectively in average. The number of empty seeds per cone and the ratios were varied with the site condition; fruited year, and individual tree. The contribution rates of these sources of variance to the number of empty seeds per cone were respectively 3.50%, 8.06%, and 55.41%. No correlationships were found between the amount of empty seeds in number or ratio and the cone production, and the D.B.H. of mother tree. However, both the number of empty seeds and the ratio of empty seeds to total seeds showed significant positive correlations with the number of 1-year-old cones per tree.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.301-308
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• 1996

In this study, a propagation characteristics of green kyllinga(Kyllinga brevifolia var. leiolepsis H.) was investigated. Two to three rhizomes(1st rhizome) arised from the basal part of main shoot at 4th leaf stage and were grown to extend on the soil surface. Then new shoots(lst tillers) emerged from every node of the 1st rhizome. Second rhizomes also arised from the basal part of lst tiller at the time of 4th leaf openning. With such a regularity, 5th rhizomes and about 688 shoots were produced from one plant during one year-cultivation without competition under the natural condition. The degree of vegetative growth and seed formation was 3 times and 2.5 times higher in rhizomeoriginated plant than in that from seed, respectively. The amount of seed formation and the 1000 seeds weight was highest in one planted on June 1 and Aug. 1, respectively. Short-day treatment of less than 14hr appeared to be necessary for the induction of flowering and it was effective as treated not during germination but since at least 2 leaf stage of green kyllinga. Each shoot individually responded to short-day. When plants were exposed to short-day (9hr, day / 15hr, night) treatment at the stage of 2-3 leaves, more than 7 cycles were required for flowering induction. Bolting in main shoot occurred after emergence of 4 leaves under the short-day condition. Exogenous $GA_3$ slightly accelerated the velocity of bolting only in short-day condition.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.169-180
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• 2012

Aster altaicus var. uchiyamae, endangered plants to grade II designated by the Ministry of Environment Korea, is only distributed in Gyeongsangbukdo, Chungcheongnamdo in Korea. In order to know the effects of elevated $CO_2$ concentration and temperature on ecological responses of A. altaicus var. uchiyamae, this study was carried out in the control(ambient $CO_2$ + ambient temperature) and treatment(elevated $CO_2$ + elevated temperature) at glasshouse. As a result, germination rate of A. altaicus var. uchiyamae was higher in control than in treatment. Period of alive leaf was longer in control than in treatment. Period of blooming and seed maturity was faster in control than in treatment. Shoot and root weight were heavier in control than in treatment. No. of inflorescence per plant and seed per inflorescence was higher in control than in treatment. Weight of inflorescence per plant, seed per inflorescence and one seed was heavier in control than in treatment. These results indicate that ecological responses of A. altaicus var. uchiyamae may be more negatively affected by elevated $CO_2$ and temperature except for phenological responses of that may be delayed under future global warming situation.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.705-714
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• 2014

This text was analyzed and investigated the aerial part plants and buried seed plants at coniferous forest and broadleaved forest in Yesan-gun, in order to offer the basic data of potential natural vegetation change on secondary forest. Plants of buried seed germination were consisted of 29 taxa in coniferous forest (28 species, 1 varieties, of 27 genus, 20 families) and 36 taxa in broadleaved forest (34 species, 2 varieties, of 32 genus, 18 families). Family classification of buried seed plant was the most in Compositae, and emergent plot frequency was the highest of Cyperus amuricus in coniferous forest and Crepidiastrum sonchifolium in broadleaved forest. The soil depth of the most plants appearance was 0~10 cm in coniferous forest and 0~5 cm in broadleaved forest, and the soil depth of the most population appearance was 0~2 cm in coniferous forest and broadleaved forest. Population of buried seed germination was decreased according as soil is deep. Crepidiastrum sonchifolium was a plant that population of buried seed germination is the most. Similarity index of the aerial part plants and buried seed plants was low as 0.22, and coniferous forest and broadleaved forest was 0.40.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.48-67
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• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.574-578
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• 2016

For the last few decades, much research has been tried to improve crop’s characteristics such as crop yield, quality, seeding period and environmental adaptability. In this paper, the effect of nanobubbles on the germination rate of barley seed is experimentally investigated. The air nanobubble was generated in water by gas-liquid mixing method. The results were shown that the mean diameter and concentration of nanobubble fabricated in DI water are 133 ㎚ and 8.59✕10⁸ particles/㎖, respectively. Also, the seed germination rate for the nanobubble water was approximately 40 % higher than that of pure water.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.297-297
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• 2009

최근 유기농산물에 대한 관심과 요구가 급증하면서 소비자들은 고품질 유기농산물을 선호하고 있어 국내 대부분 유기농가들은 무처리 일반종자를 이용하고 있는 실정이다. 앞으로 국제 기준에 부합하는 채소류 유기재배를 위해서는 유기종자의 이용이 필수적이므로 유기종자 채종체계 확립이 필요한 실정이다. 따라서 본 연구에서는 당근 종자(재래종 heimloom)를 사용하여 유기종자의 채종체계를 확립하고자 하였다. 일반적으로 당근종자 생산은 적어도 2년을 요구한다. Seed to seed 방법과 Root to seed 방법이 이용되고 있는데 본 연구에서는 Root to seed 방법을 사용하였다. Root to seed 방법은 6월에 당근종자를 파종하여 가을에 뿌리를 수확하여 지상부를 5cm 정도 남기고 정지하여 일시 저온저장 하였다가 이듬해 뿌리를 이식하여 새순에서 추대시켜 종자를 수확하는 방법으로 종자 생산성이 높아 종자회사에서 많이 사용하고 있다. 본 연구에서도 Root to seed 방법으로 채종 시험하였다. 2008년도에 파종 및 수확한 뿌리를 저온저장고에 일시 저장 후 1차 이식은 2008년 11월 하순에 노지포장에서 실시하고 이때 월동 중 동해를 막기 위하여 보온덮개로 멀칭 처리하였다. 이듬해 3월 중순에 주간거리 75${\times}$40cm 간격으로 솎음하여 처리당 10주씩 배치하였다. 이식후 뿌리에서 새순 1대를 유도하였고 추대 및 개화 6주후부터 종자가 갈색으로 변하기 시작할 때 채종을 시작하였다. 수확부위는 1차 측지 중 1번째 화지를 대상으로 하였고 화경절단은 화총으로부터 20cm 정도 남겨서 잘랐고 실내에서 1개월 이상 충분히 후숙시킨 후 종자를 정선하여 종자생산성을 조사하였다. 결실율과 발아율 조사는 채종된 종자를 이용하여 종자 충실도와 발아력을 조사하였다. 각 품종별 추대율은 15번 품종과 16번, 24번 품종이 5% 미만으로 매우 부진하였고 그밖에 추대된 묘의 생육 및 발육상은 매우 양호하여 개화에는 커다란 문제가 없었다. 종자 결실율은 23번 품종을 제외한 모든 품종에서 높았고 각 품종별 화총구조를 고려해 볼 때 주간 화총, 1차측지, 2차측지 순으로 결실율이 떨어졌다. 각 품종의 천립중은 1, 11, 12, 14, 20번 품종이 2.02g 이상으로 대립종으로 판단되며 각 품종별 화총의 크기는 비슷하여 대립종은 각 화총당 종자수가 적은 것으로 나타났다. 대분분의 대립종은 만생종으로 생육기간이 소립종 보다 10-20일상 길며 종자 성숙기간도 장기간 소요되며 특히 장마기간을 넘겨야 할 경우에는 비가림 시설 채종재배가 필수적인 것으로 나타났다. 발아율은 10, 11, 14, 18, 19, 26번 품종이 80% 이상으로 가장 높았고 다른 품종에서는 다소 떨어져 품종별 차이가 많았다. 종자 생산성은 장근종과 단근종간에 약간의 차이가 있지만 주간 화총을 포함하여 1차 측지 4-5개에서 채종하는 것이 가장 효율적인 것으로 사료된다. 또한 당근의 개화 기간을 보면 1화륜은 8~10일, 1개체는 40~50일, 채종포장에서는 1화륜에서 측지 6개구까지 채종은 60~70일 소요되어 미숙종자와 과숙종자가 혼재되어 적정 수확시기를 결정하기가 매우 어려운 점이 발생하였다. 본 연구 결과에서 생육특성, 수량성, 품질특성, 종자 생산성, 발아율을 고려해 볼 때 1, 7, 8, 9, 10, 14, 19, 26번 품종이 유기농 재배 및 유기채종에 적합한 것으로 사료되었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.327-332
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• 2010

This study was conducted to overcome the deliciousness by sex reversal in hemp plants. When female plants grown under long day length condition were transferred to short day length condition in 3th and 6th leaf stage, a few male flowers were formed and the gap of flowering days between sex reversed male and normal female flowers were around 10 days and 3 days, respectively. Although the flowering amounts were small, this short gaps of flowering days were enough for artificial pollination. When female plants grown under long day length condition were transferred to short day length condition just after treatment of silver nitrate in the vegetative stage, a great amount of male flower was formed and the gap of flowering days between sex reversed male and normal female flowers were only 1 to 3 days. The increased sex reversed male flowers and induced short gap of flowering days were adequate for natural wind pollination. When female seeds were cultivated, seed yield was 141 kg/10a, while it was 96 kg/10a when normal seeds cultivated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.188-195
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• 1987

This study was conducted to investigate whether seedling growth be affected by immature kernels from different stages after flowering in rye, triticale, wheat and oats cultivars, for two years in Suwon. Kernels reached a near-maximum test weight at 35 days after flowering in Paldanghomil and Dooroohomil (Rye), and 30 days in Sinkihomil (Triticale), Geurumil (Wheat), and Megwiri (Oats). Test weight of immature kernels from different days after flowering were not significantly correlated with germination percentage, but highly positively correlated with their seedling height, fresh and dry weight. However, seedling height is not different among seedlings from kernels harvested at 20, 25 and 30 days (maturing time) after flowering of Sinkihomil and Megwiri, and between 25 and 30 days (maturing time) of Geurumil. Also between seedlings from 25 day and 30 day-kernel after flowering are little difference of fresh and dry weight of Sinkihomil and Megwiri. In Suwon, located at the middle part of Korea, it was suggested that Paldanghomi1 and Dooroohomil could be harvested at 35 days (June 19, and June 24, respectively) after flowering, and Sinkihomil, Geurumil, and Megwiri, at 25days (June 24, June 14 and July 4, respectively) after flowering for seed of for2:ge production.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.1-5
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• 2012

A simple monitoring method was designed to evaluate seed bank in a upper soil (0 to 30 cm depth), which was observed for the pattern of vertical distribution of weed in the soil under tillage or no-tillage condition. The field experiment was established at an organic corn field located in Hwacheon in Kangwon-do from 2010 to 2011. Undistributed linear soil samples were taken using non-destructive soil sampler from 0 to 30 cm depth at the tillage or no-tillage soils. Weed seed distribution in the linear soil samples was estimated by counting the number of weed germinated according to the soil depth. Under tillage condition, the weed seeds were more evenly distributed from 0 to 30 cm depth, with being 75% of weed seeds located in 0 to 15 cm depth compared to the no-tillage condition. Soil samples taken by no-tillage condition had 85% of weed seeds within 15 cm of soil depth, with being 93% of weed seeds from 0 to 20 cm depth. The number of weeds or the number of weed species were three times higher for tillage soil compared to no-tillage soil, and the major dominant weed species were observed for annual plants, such as Echinochloa crus-gall, Mollugo pentaphylla, and Digitaria ciliaris.