Tiarella polyphylla D. Don is a native plant distributed only in Ulleung Island in Korea and has been traditionally used for medicinal purposes, although it is also used ornamentally. This study was conducted to determine the requirements for dormancy break and germination and to classify the type of seed dormancy. The experiments were performed with cold stratification (0 or 12 weeks at 5℃), warm stratification (0, 4, 8, or 12 weeks at 23℃, followed by 8 weeks at 5℃, and then incubation at 23℃), and GA3 treatments (0, 10, 100, or 1000 ㎎/L). The treated seeds were incubated on aseptic media at room chamber (23℃, a 16h photoperiod of fluorescent lamps with 40 μmol ․ m-2 ․ s-1). The seeds were dispersed in nature as underdeveloped embryos with no physical barrier to absorb water to prevent water absorption. However, the seeds did not germinate for 30 days after sowing without any pre-treatments. Thus, the seeds had morphological dormancy (MD) and physiological dormancy (PD). The final germination percentage following cold stratification (0 or 12 weeks) was 66.7% and 45.6%, respectively. The cold stratification delayed seed germination by about 3 weeks. In the warm stratification experiment (0, 4, 8, or 12 weeks), the final germination percentage was 21.1%, 27.8%, 41.1%, and 57.8%, respectively, 20 weeks after sowing. The embryos of the T. polyphylla seed grew in relatively warm temperatures (23℃). GA3 application overcame seed dormancy and promoted germination. Following GA3 treatment (0, 10, 100, or 1000 ㎎/L), the final germination percentage was 33.3%, 45.0%, 42.5%, and 72.5%, respectively. These results suggest that the T. polyphylla seeds had non-deep simple morphophysiological dormancy (MPD) and GA3 treatment could be used as a substitute for warm stratification for breaking seed dormancy. To our knowledge, this is the first report of seed dormancy characteristics of the genus Tiarella native to Korea.

This research was performed to develop mass propagation method of Alpine modest primrose (Primula modesta var. hannasanensis T.Yamaz.) for improving the conservation and utilization of the species. Seeds were collected on August 2011 in Jeju-city and well-selected seeds were dry-stored at 4 ± 1.0℃. Seed size ranged 0.44 ± 0.07 × 0.61 ± 0.04 ㎜, and weight of 1,000 seeds was 51.78 ± 0.021 ㎎. Thus the seed was classified as ‘dwarf seeds’. As the result of dormancy characteristics, moisture content of freshly matured seeds increased rapidly by water-soaking treatment and seeds did not germinate at 20℃ for 4 weeks under the light condition. Therefore, seeds were estimated to have physiological dormancy. Germination conditions of dry-stored seeds were found to be 20℃ and light condition, and seeds did not germinated under dark condition regardless of all temperature regimes. Therefore, Alpine modest primrose seed was considered as photoblastic type. Percent germination (PG) and germination energy (GE) were greatly improved by soaking the seeds in GA3 and kinetin for 24 hours. Especially, 200~500 ㎎/L GA3 treatment resulted in the highest PG (95.5%) and GE (98.3%). So, chemical treatment such as GA3 was thought to be a useful method for raising seedling uniformly.

Background: Dehisced ginseng seeds need to be stored at cold temperatures for around 3 months to break their physiological dormancy, and thus, to aid in gemination. In the presence of high moisture in such an environment, seed spoilage and pre-germination may lower seed quality and productivity. To improve seed quality during cold-stratification, the effects of seed dehydration and temperature were tested. Methods and Results: In early December, dehisced ginseng seeds were dehydrated at 4 different levels and stored at 2℃- 2℃, and –20℃ for 3 months. Germination was carried out on the filter papers moistened with distilled water; emergence of root, shoot, and seed spoilage were assessed. Seed viability was examined by the tetrazolium test. More than 90% of the seeds stored at 2℃ and –2 ℃ without drying or endocarp dehydration germinated, but seeds that were dehydrated to have a moisture content (MC) below 31% showed poor germination and lost their viability. In addition, the seeds stored at –20℃ failed to show effective germination. Conclusions: Seed storage after endocarp dehydration might help to improve seed quality and increase seedling's ability to stand during the spring-sowing of ginseng.

This research was performed to develop mass propagation method of round-leaved sundew (Drosera rotundifolia L.) for improving horticultural usefulness. Seeds were collected around Hwaseong-si, Gyeonggi-do in October of 2011 and experimented upon while being dry-stored at 4 ± 1.0℃ (darkness). Seed length of a major and minor axis were 1.58 ± 0.060 and 0.21 ± 0.016 ㎜, respecrively, and weight of 1,000 seeds was 6.24 ± 0.172 ㎎. Seeds were thus classified as ‘dwarf seeds’. Regarding the dormancy type, since round-leaved sundew seeds were dormancy broken and germinated at 20~30℃ under the light condition after wet-chilling treatment for 12 weeks, seeds were estimated to have physiological dormancy. Germination conditions of dormancy broken seeds were found to be 20℃ and light condition (54.7%), but germination decreased at higher temperature. Percent germination (PG), germination energy (GE), mean germination time (MGT) and T50 were effectively improved by chemical treatment such as GA3 200 ㎎/L + kinetin 20 ㎎/L and wet-chilling treatment for 14 weeks. In conclusion these optimal conditions were thought to be a useful method for raising seedling uniformly.

Background : Upon harvest in the summer, seeds of Panax ginseng are unmatured and need further maturation, dehiscence and cold-stratification, for germination. For the cold-stratification, the seeds should be stored in the cold temperature for 90-100 days, however no further description about the storage condition have been described even though there have been many problems in emergence rate and quality of ginseng in the spring-sowed filed. Methods and Results : Thus here we tested 3 different storage temperature(2℃, -2℃, and – 20℃) in combination of 4 different seed water content(59%, 54%, 31%, and 7%) as cold-stratification condition. After 100 days of storage, seeds were placed on the filter paper after watering with distilled water in the petri dish and incubated at 10℃. Fifty percent of seeds stored at 2℃ with 59% water content had already germinated even in the storage room before germination test. Seeds with 59% and 54% water content stored at 2℃ and –2℃ germinated in a similar rate, but emergence of above ground part was higher in the seeds with 54% water content. Seeds with 31% and 7% water content stored at 2℃ and –2℃ showed low germination rate, because of fail in stratification or death. Seeds stored at –20℃ scored even lower germination rate and fail in emergence of above ground part. Conclusion : Seed water content and temperature during the cold-stratification period of ginseng seeds affected on the seed viability and germination rate, thus control of seed water content and storage temperature might improve the emergence rate of spring-sowed ginseng filed.

Background: Developing new ginseng cultivars is a significant time-consuming process owing to the three years of growth required for ginseng to flower. To shorten the ginseng breeding process, it is necessary to establish rapid progression through each generation. In this study, we examined it was possible to rapidly break ginseng seed dormancy using gibberellic acid (GA3) treatment and alternating temperature. Methods and Results: Seeds were obtained from local variety. Seeds were treated with either GA3 at a concentration of 100 ㎎/ℓ, constant temperature (−2℃ and 2℃), alternating temperature (2℃ followed by −2℃, followed by 2℃) or a combination GA3 and temperature treatment. Following experimental treatment, seeds were sown into trays and placed in a greenhouse. Low germination rates were observed in seeds that did not receive GA3 treatment, which were similar following 2℃ and −2℃ constant temperature treatment. Germination rates increased in proportion to GA3 and more so when combined with alternating temperature treatment. In additon, stem and leaf lengths of the resulting ginseng plants were increased following GA3 treatment, although no synergistic effect was observed with alternating temperature treatment. Conclusions: These results suggest that a combination GA3 and alternating temperature treatment enhances ginseng seed germination, which can contribute to shortening the time required to progress through a single ginseng generation for breeding.

Background : When ginseng seeds were gathered, the seeds were unripe. To grow immature embryo definitely, special treatment called dehiscence must be performed. Even though dehiscence is completed, most ginseng seeds are on enforced dormancy. The breaking seed dormancy is generally achieved using cold treatment. Also it is reported that gibberellin treatment can replace the treatment. It is very time consuming process in order to develop new ginseng cultivar because ginseng flowers after 3 years of growth. To shorten the ginseng breeding period, it is necessary to establish fast generation progress. Therefore, this study examined the possibility of breaking seed dormancy of ginseng using GA3 treatment and alternating temperature. Methods and Results : Seeds were obtained from local variety fruit which is not inbred. Gibberellin of 100 ppm was treated at seeds for 24 hours. Fixed cold condition was treated on both –2℃ and 2℃. Alternating cold condition was treated on 2℃ and then –2℃, finally 2℃. Fixed and alternating temperature was continued for 15, 30, 45, 60, 90 days that 15 days of alternating temperature is first 2℃ for 5days and then -2℃ for 5days, finally 2℃ for 5days. The other treatment periods such as 30, 45, 60, 90 days mean 10, 15, 20, 30 days respectively. Each of 48 seeds were sowed on tray in greenhouse at 3 replication. Experimental plot was completely randomized. Conclusion : Seeds untreated with GA3 were germinated little and there is no difference between 2℃ and –2℃. Alternating temperature until 60days made no difference with fixed temperature but germination rate increased up to 70.8% when seeds were treated for 90days. Germination of seeds treated with GA3 is much higher than untreated seeds especially combined with alternating temperature.

Seed dormancy is an important adaptive mechanism to protect seeds under the unfavorable environments. Unlike to wild type species, the seed dormancy trait of cultivated crops has been weakened by breeding programs during the domestication period. Weak seed dormancy often causes preharvest sprouting (PHS) problem in many cereal crops that result in significant economic loss. The seed dormancy is a quantitative trait loci (QTL) controlled by multiple genetic and environmental factors. So far, many QTLs for seed dormancy have been identified from rice and wheat as well as in the model plant Arabidopsis. Unveiling of QTL genes and complex mechanisms underlying seed dormancy is accelerated by the rapid progress of crop genomics. In the present study, we reviewed current status of research progress on the seed dormancy QTLs and correlated genes in Arabidopsis and cereal crops.

Lespedeza species are mainly used for wildlife food and cover and for erosion control. The germination of these species can be enhanced after a fire occurrence in forest, which is known as fire-activated seeds to germinate. While the heat treatment could break seed dormancy of Lespedeza, its germination rate was quite low. We investigated that chemical scarification could promote germination of L. tomentosa. Seeds were soaked in 100% sulfuric acid (H2SO4) for 0, 1, 3, 6, 12, 24, 48, 96, 192, and 384 min, and then washed in distilled water for 24 h. Very few seeds were germinated in control (H2SO4 for 0 min). More than 90% of seeds were germinated in H2SO4 for 24, 48, and 92 min. However, some damage was observed in roots and cotyledons of seedling dipped in H2SO4 for a long time. To search the optimal soaking time in H2SO4 without defects, seeds scarified in H2SO4 for 30, 60, 90, 120, 150, 180, and 300 min were sown the commercial soil medium. Seeds treated with H2SO4 for 90 min and 150 min emerged by about 92% and 84%, respectively. Therefore, H2SO4 treatment could break the seed dormancy of Lespedeza species, and especially in case of L. tomentosa the optimal treatment time in sulfuric acid was one to two hours. Germination of L. tomentosa began promptly following the scarification and was completed within about one month, indicating that seeds has no physiological dormancy, just has physical dormancy.

Background : Considerable time and effort is required to develop new Panax ginseng varieties. Ginseng breeders have been developing techniques to shorten the breeding cycle to resolve this problem. In this study, we investigated the effects of adding GA3 and alternating temperature (AT, 2℃→ −2℃ → 2℃) on breaking bud dormancy in the varieties (Chungsun and Sunun) of ginseng root. Methods and Results : The GA3 soaking treatment and AT were applied to one year old roots, which greatly accelerated the emergence of new buds. In one year old roots, new buds emerged from the 4th day post transplanting and after breaking dormancy with GA3 and AT treatments. The emergence of new buds was completed within two weeks. The rate of bud emergence for Chungsun was 60% - 98% over 15 - 60 days after the AT and GA3 treatments. The emergence rate of Sunun was 46% - 92%. Normal growth of the ginseng seedling was observed in spite of the early breaking of bud dormancy by combined GA3 and AT treatments. Conclusions : GA3 and AT treatments shortened the dormancy period and facilitated the stable emergence of ginseng seedlings. However, some plants suffered deformities and early sprouting owing to the combined GA3 and AT treatments. Early sprouting was free from dormancy after leaf fall from the of aerial part of the plant.

‘고운’은 농촌진흥청 국립식량과학원 고령지농업연구센터에서 가을재배용 칩가공용 품종을 육성하고자 1998년 건물함량이 높은 가공용품종 ‘Lemhi russet’와 수량성이 높은 단휴면 2기작 식용품종인 ‘추백’을 인공교배하여 육성하였다. 그후 봄재배와 가을재배를 통하여 실생세대와 생산력검정예비시험, 생산력검정본시험을 거치면서 H98005-4를 선발하였으며, 2005년과 2006년에 걸쳐 제주, 남해, 강릉 등 3지역에서봄, 가을재배를 통해 지역적응시험을 실시한 결과 그 우수성이 인정되어 2006년 농작물 직무육성 신품종 선정위원회에서국가목록 등재품종으로 선정되었다. ‘고운’은 남부 해안 2기작감자 재배지역에 적응하는 칩가공용 감자품종으로 숙기는중간정도이다. 반직립형으로 생장하며, 꽃색이 흰색이고, 자연조건하에서 열매는 거의 달리지 않는다. 괴경모양이 짧은 계란형으로 육색이 흰색이며, 내외부 생리장해 발생이 적다. 괴경의 건물함량이 높고 환원당 함량이 낮아 칩가공성이 우수하다. 괴경의 휴면기간은 수확후 60～70일 정도이다. 더뎅이병과 역병에 대하여 중도저항성이지만 감자바이러스Y에는 약하기 때문에 씨감자 채종재배시 진딧물 방제를 철저히 하여야한다. 풋마름병에 대해서는 저항성이 없으므로 풋마름병 발생지역에서는 재배하지 말아야 한다. ‘고운’의 수량성은 2005년부터 2006년까지 2년간 실시한 지역적응시험 결과 봄재배시33.2 ton/ha, 가을재배시 26.2 ton/ha로 나타나 ‘Dejima’에 비하여 각각 87%, 86%의 수량성을 보였다. ‘고운’의 적응지역은 전라북도 해안지역과 전라남도와 경상남도의 2기작감자 재배지역이다.

자운영 지속재배시 토양에 매몰된 종자의 휴면 및 발아특성을 조사하여 토양속 종자 동태를 구명하기 위해 자운영종자와 꼬투리의 토양매몰 깊이 및 기간별 휴면성과 종자활력 변화를 조사하고 또한 자운영 지속재배 포장에서 낙수후 자운영 종자의 토양속 분포 개수, 발아율 및 종자활력기간을 조사한 결과는 다음과 같다. 1. 자운영 종자 회수율은 종자 매몰 한달후부터 활력이 잃기 시작하여 낙수전 9월까지 52~65%, 낙수후 10월에는 급격히 떨어져 종자와 꼬투리 모두 30% 이하를 나타내었고, 꼬투리 매몰의 경우는 낙수전 9월까지 활력소실이 되지 않고 100%를 보였다. 2. 자운영 종자의 휴면은 수확당시는 95%로 높았으나 시간이 경과함에 따라 점차 파괴되어 9월에는 휴면율(경실율)이 종자는 12~22%, 꼬투리는 31~33%로 급격히 낮아졌고, 낙수후 10월에는 경실율이 종자는 2~8%, 꼬투리는 5~12%로 보다 더 낮아졌다. 3. 발아율은 토양 매몰전 종자는 4%로 낮았으나 토양에 120일간 매몰후 종자 및 꼬투리속 종자 발아율은 휴면이 타파되어 각각 21%~31%, 49~51%로 증가하였다. 4. 자운영 지속포장에서 9월 낙수후 토양속 잔존 자운영 종자는 로터리 부분경운이앙은 경운이앙보다 2.3~2.6배가 많았고, 자운영 종자분포 깊이는 로터리 경운은 0~15 cm 깊이에 고르게 분포되었으나 부분경운 이앙은 대부분의 종자가 5cm 이하 깊이에 분포하고 있었다. 5. 자운영 종자의 출아기간을 기준으로 한 토양 속에서 활력유지기간은 매몰 후 2년정도 인 것으로 조사되었다.

This study was carried out for the improvement of germination rate by breaking seed dormancy in barley, In spring and fall planting, Post-harvest treatment of seeds such as air-dried (24 hours) or soaked in the 100 ppm gibberellin for 10 to 30 minutes imp

앵초, 설앵초와 애기나리를 인위적으로 저온 처리하여 조기에 휴면 타파시켜 동계 생산에 필요한 저온요구시간을 구명하고자 저온시간을 각각 300, 500, 700, 900시간으로 처리하여 수행한 결과 앵초는 700시간이상, 설앵초와 애기나리는 모두 500시간 이상 저온(5℃)을 받으면 화경장이 신장되고 개화율도 높아지는 것으로 보아 휴면이 완전히 타파된 것으로 판단되었다. 따라서 앵초, 설앵초와 애기나리의 동계생산을 위해서는 5℃의 저온에 500~700시간 이상을 두었다가 온실로 옮겨 재배하면 2월 상순에 분화상품 생산이 가능할 것으로 생각된다.