감나무의 휴면 정도에 따른 내동성을 비교하고자 '부유', '상서조생', '서촌조생', 갑주백목', '청도반시' 등의 1년생 가지를 1월 20일, 2월 20일, 3월 20일에 각각 채취하여 -5, -10, -15, -20, -25 및 -30℃ 등으로 처리한 후 전해질 누출률, TTC 검정 및 눈의 발아율을 조사하였다. 전해질 누출률은 1월 20일의 가지에서 가장 낮았고, 3월 20일의 가지에서 가장 높았다. '부유'라 '청도반시' 가지의 전해질 누출률은 1월 20일에서 높았고 2월 20일에는 낮았으며, '상서조생'과 '서촌조생'은 반대의 경향이었고, '갑주백목'은 중간 정도 수준이었다. TTC 검정을 통한 흡광률은 1월 20일의 가지에서 가장 높았고, 2월 20일과 3월 20일의 가지에서는 낮았다. '부유'와 '상서조생' 가지의 흡광률은 1월 20일과 3월 20일에서 낮고 2월 20일에서는 높은 경향이었다. '서촌조생'과 '갑주백목'의 가지는 채취시기에 관계없이 높은 수준이었다. 눈의 발아율은 2월 20일의 가지에서 가장 높았고 3월 20일의 가지에서 낮았다. 그리고 대부분 품종의 발아율은 휴면정도에 관계없이 -20℃ 처리에서 전혀 발아하지 않았다. '부유', '서촌조생' 및 '청도반시'의 가지는 휴면정도에 관계없이 비교적 높았지만 '상서조생'의 가지는 낮았다. '갑주백목'의 가지는 1월 20일에만 높은 수준이었다. 따라서 감나무의 내동성은 휴면 타파 후 가장 약하며, 떫은감과 단감 간 차이는 거의 없는 것으로 생각된다.

치커리(Cichorium intybus L.)의 우량 종근 생산을 위한 휴면 특성을 구명하기 위해 시기별로 생육 특성과 ABA 함량을 조사하였다. 5℃ 이하의 저온누적시간은 10월 7일부터 12월 3일 조사까지는 서서히 증가하는 경향을 나타내었으나 이후 증가폭이 커졌다. 종근 무게는 10월 말부터 12월 3일 조사까지 큰 폭으로 증가하였으나, 이후부터 12월 17일 조사까지 거의 증가하지 않았다. 종근 내 ABA 함량은 10월 7일부터 12월 3일 조사까지 아주 낮은 수준으로 변화가 거의 없었으나, 이후 12월 10일 조사에서 급격히 증가하였고 2주후인 12월 24일 조사에서 급격히 감소하였다. 따라서 5℃이하의 저온누적시간이 큰 폭으로 증가하고 종근 무게가 변화하지 않는 시기, 그리고 ABA 함량이 급격히 증가하는 시기를 고려하면, 치커리는 12월 3일 이후부터 대략 2주간 내재 휴면을 하고 이를 타파하기 위한 저온요구시간은 대략 240시간 정도로 생각된다.

포도 시설재배시 년 2기작 재배를 하려면 가장 문제가 되는 것이 여름의 휴면타파에 의한 2차 생장의 유도이다. 본 연구에서는 근권환경조절에 의하여 토양수분조절과 휴면타파제 처리에 의하여 발아율을 높이기 위한 연구를 수행하였다. 근권수분조절에 의하여 신초의 등숙을 7, 8월에 유도할 수 있었다. 근권환경조절에 의하여 1차 생장은 일반 시설재배의 신초생육과 차이가 없었다. 2기작 재배를 위한 휴면타파 처리제는 시아나미드화합물에 메리트청을 혼합한 구가 75% 이상의 높은 발아율을 나타내었다. 신초 등숙 유도를 위한 수분중단구가 수분공급구 보다 발아율이 높았다. 결실 신초율은 처리간 타이가 없었으나 신초발아 시기가 균일하지 않았다

저선량 γ선 조사가 기내 유기한 대지와 수미 감자 소괴경의 맹아율과 식물체 생장 및 생리활성에 미치는 효과 등을 알아보고자 감자 소괴경의 저장기간별로 γ선을 0.5~30Gy 까지 조사하여 pot실험을 수행하였다. 감자 소괴경의 휴면과 생육에 대한 저선량 γ선 효과는 품종과 저장기간에 따라 다소 차이가 있었다. 대지 품종의 경우 대체로 2,4,8Gy에서 대조구에 비해 높은 맹아 출현율을 보였고,

Liatris spicata 구경(球莖)의 휴면도입기(休眠導入期) 및 휴면각성기(休眠覺醒期)를 조사(調査)함과 동시(同時)에 GA처리(處理)에 의(依)한 휴면타파효과(休眠打破效果)를 조사(調査)한 결과(結果)는 다음과 같다. 1. 맹아율(萌芽率), shooting율(率) 및 발근율(發根率)은 8월(月) 30일(日) 이후(以後) 서서히 저하(低下)되어 11월(月) 14일경(日頃) 가장 낮은 경향(傾向)을 보이다가 이후(以後) 서서히 증가(增加)하여 1월(月) 29일(日) 이후(以後)에는 모두 100%로써 매우 양호(良好)하였다. 2. 출아소요일수(出芽所要日數)에 있어서도 11월(月) 14일(日) 무처리구(無處理區)에 있어서 10.1일(日)로써 가장 길었으며 1월(月) 29일(日) 이후(以後)에는 급격(急激)히 단축(短縮)되었다. 3. 맹아(萌芽) 및 shooting 상태(狀態)를 봐서 대구지방(大邱地方)의 노지(露地)에서 Liatris spicata 구경(球莖)의 휴면도입기(休眠導入期)는 9월(月) 하순경(下旬頃), 휴면기(休眠期)는 11월(月) 중순경(中旬頃), 휴면각성기(休眠覺醒期)는 1월(月) 하(下)~2월(月) 초순경(初旬頃)이라고 사료(思料)된다. 4. 구경(球莖)의 휴면타파효과(休眠打破效果)는 GA 200ppm 1시간(時間) 침지처리(浸漬處理)로 효과(效果)가 인정(認定)되었으며 특히(特)히 휴면(休眠)이 깊을수록 그 효과(效果)는 더욱 증가(增加)되는 경향(傾向)을 보였다.

This study was conducted to determine the number of days required to break a plant’s dormancy and promote subsequent crop growth in new varieties of Gomchwi through the 4℃ treatment. Three new varieties of Gomchwi namely, ‘Sammany’, ‘Gommany’, and ‘Damogy’ were observed in this study. The rate of leaf emergence of ‘Sammany’ after 15-day of 4℃ treatment was 100%, while ‘Gommany’, and ‘Damogy’ took 20-days and 10-days, respectively to reach to 97.9% rate of leaf emergence. After 10-days of 4℃ treatment, ‘Damogy’ grew faster than the other varieties. and Harvest time for ‘Damogy’ was on January 18th, after 5-days of 4℃ treatment and yield was observed to be the highest at 15-days of 4℃ treatment. ‘Sammany’ was next with a minimum of 10-days of 4℃ treatment, although 15-days is more preferred for better harvest. ‘Gommany’ on the other hand, did not grow enough for harvest by January 18th, and its harvest time was delayed to January 31st. It needed a minimum of 15-days and preferentially 20-days of 4℃ treatment to grow normally and be ready for harvest. The plant height, leaf length and leaf petiole length appeared to grow better by extending duration of the 4℃ treatment. The number of leaves of ‘Sammany’ and ‘Gommany’ varieties was three leaves for the 5-days treatment which may be due to the incomplete breaking of dormancy. Regarding the yield per plant, ‘Sammany’ yielded 112.3 grams (g) in 15-days treatment, and ‘Gommany’ yielded 106.5 g in 25-days treatment. In the case of ‘Damogy’, it yielded 123.5 g and 183 g in the 10-days and 25-days treatment respectively. It is concluded that ‘Damogy’, ‘Sammany’ and ‘Gommany requires 10, 15, and 20 days of 4℃ treatment to break the plant’s dormancy and promote better plant growth.

본 연구는 각시괴불나무 종자의 휴면유형과 발아특성을 구 명하기 위하여 수행되었다. 수분흡수 실험결과, 각시괴불나무 종자는 수분흡수가 원활히 이루어졌다. 따라서, 물리적 휴면은 가지지 않는 것으로 판단된다. 각시괴불나무 종자는 탈리 시점에 미숙배를 가지고 있으며, 발아직전까지 배/종자 비율이 약 46% 증가하였다. 온도실험결과, 5℃에서는 발아가 전혀 이루어지지 않았다. 20℃에서는 파종 후 1주부터 발아가 시작되었으며 최종 발아율은 2주차에 86.7%였다. 15℃에서는 파종 후 2주부터 발아를 시작하였으며, 최종 발아율은 4주차에 75.0%였다. 25℃에서 파종 후 1주부터 발아가 시작되었으며 최종 발아율은 19주차에 48.3%였다. 결론적으로, 각시괴불나무 종자의 발아를 위한 최적온도는 가장 높은 최종 발아율과 가장 짧은 평균 발아 일수를 나타낸 20℃이다. 각시괴불나무 종자는 5℃를 제외 한 모든 온도에서 4주 이내에 발아하였기 때문에 생리적 휴면은 관찰되지 않았다. 따라서, 각시괴불나무 종자는 오직 형태적 휴면만을 가지는 것으로 판단되었다.

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.

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: 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.

This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T50. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA3 and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.

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.