This study was conducted to develop a seed propagation protocol of Hemerocallis taxa native to the Korean Peninsula. In this study, the seed dormancy types were classified. The germination traits of H. thunbergii, H. dumortieri, H. hakuunensis, and H. hongdoensis were also characterized. The initial embryo to seed length ratio (E:S ratio) in seeds of the four Hemerocallis species was between 0.80 and 0.90 at harvest, however, the E:S ratio did not increase until just before germination. Thus, seeds of the four Hemerocallis species had no morphological dormancy (MD), and at least 84% of seeds of all tested species germinated at 25/15℃ under light within 30 days. The lower the incubation temperature, the lower the germination rate of seeds of the four Hemerocallis species. However, the temperature range for germination was expanded due to old stratification. Gibberellin treatment increased the germination rate or germination speed at a relatively low temperature of 15/6℃. However, this treatment did not improve the germination rate as much as the temperature at 25/15℃. Under 15/5℃ of incubation, cold stratification increased the final germination percentage and rate/speed and expanded the temperature range for germination from high to low (25/15℃ → 15/6℃). This indicates that the seeds have a conditional dormancy (CD) that germinates in a narrow temperature range. In conclusions, the four Hemerocallis seeds exhibited nondeep physiological dormancy.

Iris laevigata, which belongs to the Iridaceae, is now designated as an “endangered” (EN) grade by Korea Forest Service because it does not have many natural sites known for its reckless development and damage to its natural habitats. This study was carried out to establish the propagation protocol from seed to restore the native habitat of the I. laevigata and to utilize it for ornamental purposes. Basically, the appearance and internal structure of seeds were observed and imbibition experiments were conducted. Germination rate was measured by cold stratification experiment, after warm followed by cold stratification experiment, and GA3 treatment experiment. The seeds had underdeveloped embryos, which had grown to about 25% of those of fully matured seed before germination. In the controlled laboratory experiment, after cold stratification at 5°C for 0, 4, 8, or 12 weeks, the seeds germinated to 0, 11.7, 43.4, or 51.7%, respectively, after 4 weeks of incubation at 25°C. After warm stratification (25°C, 8 weeks) followed by cold stratification for 0, 4, 8, or 12 weeks, the seeds germinated to 0, 51.7, 85.0, or 88.3%, respectively, after 4 weeks of incubation at 25°C. GA3 treatment did not overcome the dormancy. Our study determined the dormancy type of I. laevigata seed. Imbibition experiments showed that there was no physical dormancy, and it was also found that there was an underdeveloped embryo when it was observed that the embryo was growing according to the period of incubation. A nd t he e m bryo grew a t relatively w arm temperatures. It is concluded that the seeds of I. laevigata have morphophysiological dormancy (deep simple MPD). This is the first report to determine the dormancy type in seeds of this valuable ornamental plant.

본 연구는 제비꽃과 남산제비꽃 종자의 종자휴면을 구명하고 종자 저장에 따른 발아 특성을 알아보는 것을 목표로 하고 있다. 먼저 장기 저장 종자를 대상으로 다양한 배양 온도, 저온층적처리, GA3처리를 수행하였다. 휴면의 유무를 판단하기 위해 종자를 25/15, 20/10, 15/6°C 온도에서 배양하였고 제비 꽃 종자의 최종 발아율이 각각 86, 66, 66%으로 나타났다. 이는 제비꽃 종자에 휴면이 없는 것으로 여겨진다. 남산제비꽃은 최종 발아율이 50% 이하이며, 4주 이내에 거의 발아를 하지 않아 생리적휴면이 있다고 판단된다. 남산제비꽃 종자에 GA3 1000mg･L-1를 처리했을 때 최종 발아율이 100%로 나타났다. 또한 저온층적처리 실험 결과 남산제비꽃 종자가 저온 층적처리 기간이 증가할수록 최종발아율도 증가하였다. 앞의 실험은 장기 저장이 되었던 종자를 사용한 것이며 채종 직후의 제비꽃, 남산제비꽃의 발아양상도 살펴보았다. 제비꽃은 25/15°C에서 1주 만에 모두 발아를 하여 종자 휴면이 없는 것을 다시 확인하였다. 장기 저장 종자에 비해 평균발아일수가 줄어들고 발아속도가 증가하여 제비꽃 종자는 장기 저장 중에 종자의 활력이 감소됨을 알 수 있었다. 바로 채종한 남산제비 꽃 종자도 4주만에 발아가 거의 이루어지지 않고 저온층적처리를 통해 발아율이 향상 되는 것으로 보아 생리적휴면을 가지고 있다고 재확인되었다. 따라서 제비꽃과 남산제비꽃은 장기 저장에 따라 종자의 휴면 유형은 변하지 않지만 종자 활력 에 따라서 최종발아율, 평균 발아일수, 발아속도, 발아균일도가 달라질 수 있다.

The microstructure observation of seed surface structure is needed for protocols of breaking dormancy of seeds with physical dormancy. The seeds of Rubus species are surrounded by a thick, hard endocarp; together, the seed and endocarp make up the stone. We evaluate stone characteristics of 18 species of Rubus through optical microscopic observation, and correlate different stone characteristics with endocarp thickness. As a result of stone size comparison, Rubus species were classified as big stones group including R. parvifolius and R. idaeus, small stones group including R. longisepalus var. longisepalus, R. corchorifolius and R. hirsutus, and middle stones group including rest of the species. The result of this study revealed that stone size and the endocarp thickness in Rubus species was various characteristics in each species. Furthermore stone size and stone weight were also well correlated endocarp thickness and result indicated that heavy stones had harder endocarp than lighter one. Thus from the result of this study it can be presumed that only one stone characteristic approach may be sufficient to estimate other characteristics in Rubus.

섬쥐똥나무는 울릉도의 숲 지대에 자생하는 한국 특산식물 이다. 본 연구는 섬쥐똥나무 종자의 휴면유형을 분류하기 위 하여 GA3 처리(0, 10, 100, 1000mg･L-1), 저온층적처리(5℃에 서 0, 4, 8, 10주), move along test를 수행하였다. 각각 처리 한 종자는 25℃로 유지되는 생장상에서 25μmol･m-2 ･s-1의 광 도로 16시간 일장조건에서 배양하였다. 섬쥐똥나무 종자는 배 가 완전히 성숙한 상태로 탈리되며, 불투수성이 존재하지 않 았지만, 무처리 상태에서 4주동안 발아하지 않았다. 따라서 섬쥐똥나무 종자는 생리적 휴면을 가지고 있는 것으로 판단하 였다. GA3 처리실험 결과 각 처리(0, 10, 100, 1000mg･L-1)별 로 최종발아율은 각각 30.0, 40.0, 53.3, 38.3%를 기록하였다. 저온처리 실험결과 모든 처리구에서 저온이 끝나고 15-16주의 시간이 지난 다음 발아를 시작하였다. 온도 처리별 실험결과 15℃처리에서 6주만에 발아를 시작하여 17주차에 약 88.3%, 20℃ 처리에서는 13주차에 발아를 시작하여 19주차에 약 Fig. 6. Germination of Ligustrum foliosum seeds as affected by light conditions. Seeds were incubated at 15℃ under light (16 h) or dark conditions during 11 weeks after soaking seeds in 1000 mg·L-1 GA3 solution for 24 h. Control seeds were soaked in distilled water for 24 h. Error bars indicate mean ± SE of three replications. www.ijfs.org Flower Res. J. (2017) 25(3) : 124-132 131 98.8%, 25→20→15℃처리는 15주차에 발아를 시작하여 17주 차에 약 98.8%, 5→15→20℃처리는 16주차에 발아를 시작하 여 20주차에 약 31.6%, 25℃에서는 17주차에 발아를 시작하 여 20주차에 약 38.3%의 최종발아율을 기록하였다. 반면, 5℃ 처리에서는 발아가 이루어지지 않았다. 위 결과들을 종합해보 면 섬쥐똥나무 종자는 생리적 휴면을 가지고 있고, 세부 유형 으로 non-deep PD 유형을 가지고 있는 것으로 판단된다.

간척지에서 자생하는 자귀풀은 콩과잡초로서 휴먼성이 강하 고 종피가 딱딱한 껍질에 싸여있어 채종한 종자는 발아율이 저조하므로 발아율을 높이기 위하여 황산, 온도 및 모래를 을 이용한 종피파상 방법을 이용한 휴면타파 효과를 구명하기 위 하여 본 시험을 수행하여 그 결과는 다음과 같다. 1. 2013년도 간척지에서 채종한 자귀풀 발아세와 발아율은 18.0%와 27.0%, 2014년 채종 종자는 15.8%와 21.5%을 보였다. 2. 자귀풀 종자의 황산처리효과는 황산용액 50% 처리에서 는 무 처리와 큰 차이를 보이지 않았지만, 황산용액 100% 처 리에서는 채종 연도와 관계없이 71.0% ~ 73.0%의 발아율을 나 타내었다. 3. 온도처리 효과는 90oC 고온 상태에서 각각 20, 30, 40분 처리시의 발아율은 처리시간 40분에서 90% 이상의 높은 발아 율을 보여 처리시간이 길어질수록 발아율은 증가할 것으로 사 료된다. 4. 모래를 이용한 종피파상 처리는 2014년 채종한 종자는 종자량과 모래의 비율이 4배 처리에서 94.0%로 가장 높은 발 아율을 보였고, 2배 처리에서도 80%의 발아율을 나타내었다. 이상의 결과를 종합하면 간척지에서 채종한 자귀풀의 휴면 타파는 많은 노력이나 시설 및 비용이 추가되는 온도처리나 황산처리보다 주변에서 쉽게 구할 수 있는 모래를 이용한 종 피파상법이 좋을 것으로 사료된다.

산형과 식물의 종자는 형태생리학적 휴면을 하고 있는 것으로 알려져 있다. 형태생리학적 휴면은 배가 미숙하고 생리적으로 휴면상태인 종자휴면중의 하나이다. 본 연구는 산형과의 세 종, 갯기름나물, 고본, 갯방풍 종자의 휴면타파와 발아에 미치는 온도, 광, 화학물질의 효과에 대하여 조사하였으며 그 결 과는 다음과 같다. 1. 본 시험에 사용된 종자의 크기는 길이 5.57 - 9.7 mm, 폭 3 - 7 mm 범위였고, 천립중은 갯기름나물 0.50 g, 고본 0.21 g, 갯방풍 17.53 g 이었다. 2. 예냉, 광, GA3, KNO3, 그리고 온도조건을 달리하여 전처리를 실시한 결과, 갯기름나물, 고본, 갯방풍의 최대 발아율은 각각 62.6%, 43.3%, 36.4%였다. 3. 갯기름나물은 4oC에서 7일 동안 예냉처리 하였을때 휴면 타파와 발아에 가장 효과적이었고 GA3의 저온 대체효과는 없었으며 20oC 항온조건에서 발아에 적합하였다. 4. 고본의 경우도 갯기름나물과 유사하게 4oC에서 7일간 예냉처리 하였을때 효과적이었으며 GA3와 KNO3 처리는 휴면타파에 효과가 없었다. 갯기름나물과 고본 두 종은 휴면타파와 발아를 위해 저온을 필요로 하였다. 5. 갯방풍은 GA3 200 mgL−1 처리가 발아에 효과적이었고 15/20oC(16/8h) 변온조건과 20oC 암조건에서 비교적 잘 발아하였다.

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.

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.