Seung Youn Lee

• Ph.D. , Andong National University
• Professor (Associate) at Andong National University

Veronicastrum sibiricum is a perennial species distributed in Korea, Japan, Manchuria, China, and Siberia. This study aimed to determine the requirements for germination and dormancy break of V. sibiricum seeds and to classify the kind of seed dormancy. Additionally, its class of dormancy was compared with other Veronicastrum and Veronica species....

• Disjunct species in the same genus are a common feature of the flora in the temperate forests of East Asia and eastern North America. This study aimed to evaluate whether the kind of seed dormancy was maintained after species in the genus Asarum (Aristolochiaceae) were separated from their common ancestor. • We classified the seed dormancy of Asa...

Abstract Thalictrum uchiyamae Nakai is an herbaceous perennial plant that has potential for greater utilization for landscaping and medicinal purposes. In the present study, we investigated some of the factors that affect seed dormancy and germination in this species. To determine the temperature requirements for embryo growth and germination in fi...

Although it has been speculated that Hosta seeds have an underdeveloped embryo and morphological (MD) or morphophysiological dormancy (MPD), no detailed studies have been carried out to definitively confirm this suggestion. Our first purpose was to determine if embryos of six Korean species of Hosta (H. capitata, H. clausa, H. jonesii, H. minor, H....

Acer tegmentosum, an indigenous medicinal plant under threat from overexploitation, is a deciduous tree species native to Northeast China, southern regions of the Russian Far East, and Korea. In this study, we analyzed the characteristics of samaras (single-seeded fruit) of A. tegmentosum to determine the type of seed dormancy as well as to identif...

Morphophysiological dormancy (MPD) is considered one of the most primitive dormancy classes among seed plants. While extensive studies have examined the occurrence of endo-β-mannanase in seeds with physiological dormancy (PD) or non-dormancy, little is known about the activity of this enzyme in seeds with MPD. This study aimed to investigate the te...

Trillium tschonoskii Maxim, a perennial species of the Liliaceae family, possesses significant ornamental potential for its use in gardens but is classified as an endangered species (EN category) on the Korean Peninsula. We studied the phenology of a seed dormancy break in a natural environment. The seeds had underdeveloped embryos, measuring less...

Prunus spachiana (Lavallée ex Ed.Otto) Kitam. f. ascendens (Makino) Kitam leaves exert natural anti-inflammatory effects by inhibiting nitric oxide formation. P. spachiana flowers bloom earlier than other Prunus spp. and thus could serve as a valuable resource for the horticulture and pharmaceutical industries. However, its seed dormancy class and...

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...

This study was conducted to determine the dormancy types and optimal germination conditions of Prunus mandshurica seeds. The pericarp of P. mandshurica seeds was presumed to be the reason for their poor water absorption. After the pericarp was removed with a razor blade, germination was observed to be less than 20.0% at all temperatures except at 5...

The purpose of this study was to classify the seed dormancy types of six Clematis species and to determine the germination conditions. The length of the embryo was measured, and germination was studied at warm (25°C/15°C) and cold (5°C) temperatures. Furthermore, germination was studied in light and dark conditions. All six species had underdevelop...

Background Euphorbia jolkinii Boiss. is a perennial species native to Jeju Island and the southern coastal area of Korea. Particularly on Jeju Island, the yellow flowers of E. jolkinii Boiss. have a high ornamental value because of their contrast with basalt. This study was conducted to investigate the effects of different temperatures (5, 15, 20,...

Herbaceous peony is a common perennial plant that is used as a garden or medicinal plant in temperate regions and is commercially grown as a cut flower. Because the natural flowering period is from May to June, various methods have been developed to extend the flowering period. In our previous study, peonies were forced under greenhouse conditions...

These studies were conducted to investigate the growth and flowering responses of Lysimachia mauritiana Lam. to photoperiod and cold treatment (Expt. 1) and to determine juvenility in floral induction (Expt. 2). In Expt. 1, eight-week-old seedlings with 4–6 leaves were treated with cold at 5℃ with a 9/15 (day/night) h photoperiod for 0, 3, 6, 9, an...

These authors contributed equally to the work. Abstract Gymnospermium microrrhynchum is an herbaceous perennial plant in the Berberidaceae family and is a vulnerable species in Korea. We examined the embryo growth and germination of G. microrrhynchum in terms of temperatures under both outdoor and laboratory conditions. G. microrrhynchum seed consi...

This study was conducted to determine the effect of benzyladenine (BA) and ethephon application on crown bud formation in two Hosta taxa native to Korea and one cultivar. Hosta yingeri, H. minor f. alba, and H. ‘White Edge’ were divided into uniform single-bud divisions from mother plants on April 8, 2017. BA and ethephon were applied individually...

The seed germination characteristics of eight Korean native Veronica species (V. dahurica, V. rotunda, V. kiusiana var. diamantiaca, V. pusanensis, V. rotunda var. subintegra, V. nakaiana, V. pyrethrina, and V. kiusiana var. glabrifolia) were evaluated, and seed dormancy types (kinds) were classified. Among the study species, V. kiusiana var. diama...

This study was conducted to develop a protocol for the vegetative propagation of Patrinia rupestris (Pall.) Juss., to facilitate its use for ornamental and medical purposes. Cuttings of P. rupestris were treated with distilled water (control), commercial rooting powder (Rooton, 0.4% 1-naphthylacetamide), α-naphthalene acetic acid (NAA), and indole-...

A Hosta cultivar ‘Neulpureum 1’ was bred at the Korea National Arboretum, which produces new cultivars using vegetative propagation techniques. The new cultivar ‘Neulpureum 1’ was derived by crossing Hosta minor with Hosta ‘Krossa Regal’. Among the induced leaf-color- and shape-modified hosta plants, the plants that exhibited deep-green color and s...

Lychnis wilfordii (Regel) Maxim is an endemic plant species that occurs in the wetlands of Gangwon-do, Korea. This research was conducted to investigate the effect of after-ripening treatment (0, 3, 6, or 9 weeks at 20-25°C), cold stratification (0, 3, 6, or 9 weeks at 5°C), and GA3 treatment (0, 10, 100, or 1000 mg·L-1) on L. wilfordii seed germin...

This study was conducted to determine the effects of artificial lighting sources on vegetative growth of Phalaenopsis and Doritaenopsis (an intergeneric hybrid of Doritis and Phalaenopsis) orchids. One-month-old plants were cultivated under fluorescent lamps, cool-white light-emitting diodes (LEDs), or warm-white LEDs at 80 and 160 μmol·m-2 ·s-1. T...

The aims of this study were to determine the requirements for dormancy break and germination and to characterize the type of seed dormancy of T. rochebrunianum. Ripe seeds (achenes) were collected in late Sept. To determine the temperature requirements for embryo growth and germination in the field, the seeds were sown in field soil. Every 1 or 2 w...

The aims of this study were to determine the requirements for dormancy break and germination and to characterize the type of seed dormancy of T. rochebrunianum. Ripe seeds (achenes) were collected in late Sept. To determine the temperature requirements for embryo growth and germination in the field, the seeds were sown in field soil. Every 1 or 2 w...

Thalictrum species belongs to the Ranunculaceae and are perennial landscape plants which are available in the garden and potted plants. This experiment was conducted to find out the basic data for the growth effects of fertilizer levels and shading rate in seedling plug cell tray in the Thalictrum rochebrunianum, T. uchiyamai and T. coreanum. For T...

This study was conducted to prevent flower bud abortion in forcing culture of herbaceous peony. When dormant rootstocks of Paeonia lactiflora 'Taebaek' were subjected to dormancy-breaking treatment (0°C for 6 weeks) in November, this could hasten flowering in early spring. However plants chilled in August, September, or October produced abnormal fl...

The genus Jeffersonia, which contains only two species, has a trans-Atlantic disjunct distribution. The aims of this study were to determine the requirements for breaking dormancy and germination of J. dubia seeds and to compare its dormancy characteristics with those of the congener in eastern North America. Ripe seeds of J. dubia contain an under...

Jeffersonia dubia is a spring-flowering perennial found in rich forests in Korea and Northern China and has potential as an ornamental or medicinal plant. However, illegal picking and land use change have decreased the number of populations and overall population size of this plant in its natural habitat. Although J. dubia has been reported to be a...

This study was conducted to investigate flower bud differentiation and to determine the chilling requirements for bud dormancy breaking and sprouting in Erythronium japonicum Decne. (Liliaceae). Dormant bulbs grown in an open field were randomly selected from June 2012 to December 2013 for observation of flower bud differentiation and development....

Heloniopsis koreana and Heloniopsis tubiflora (Melanthiaceae) are endemic herbaceous species of the Korean Peninsula. The Melanthiaceae family has been described as having seeds with small, underdeveloped embryos at the time of dispersal, and morphological (MD) or morphophysiological dormancy (MPD). However, there are few reports on embryo growth,...

Jeffersonia dubia is an herbaceous perennial and has the potential to be used as ornamental planting. To shorten the long cultivation period of J. dubia, effect of concentration in nutrient solution on the growth of J. dubia was evaluated. In the 1 st experiment, to compare the physiological responses to the fertilization treatment, plants were sub...

This study was conducted to find basic information for the research of morphological dormancy in seeds of two genera (Heloniopsis and Thalictrum) native to Korea. Seeds of Heloniopsis koreana, Heloniopsis tubiflora, Thalictrum rochenbrunianum, Thalictrum uchiyamai, and Thalictrum coreanum were collected, and embryo morphology and seed germination w...

The foliage of variegated Solomon's seal is excellent in cut flower arrangements. However, it has a restricted marketing period because the harvesting is limited in spring and summer. The increased interest requires the year-round production, thus techniques for dormancy breaking and forcing without low temperature treatment is needed. Therefore, e...

Heloniopsis koreana Fuse, N. S. Lee & M. N. Tamura is native to Korea and has a great potential to become a new ornamental plant for decorative purposes in gardens, in pots and landscape due to attractive reddish-purple flowers and evergreen leaves. Therefore, we observed the effects of leaf parts and growing media on rooting and shooting of H. kor...

The Ranunculaceae is a family reported to have morphological dormancy (MD) or morphophysiological dormancy (MPD), with underdeveloped embryos. There are few reports on seed dormancy and germination in Adonis amurensis. This research was performed to determine the type of dormancy for A. amurensis seeds and its dormancy-breaking requirements. Phenol...

Herbaceous peonies are common perennials that have been used as garden or medicinal plants throughout temperate regions of the world and have been grown commercially as cut flowers for many years. Because of its short flowering period from May to June, off-season culture is needed. In our previous research, peonies were forced under greenhouse cond...

To find optimum temperature on growth after dormancy release of variegated Solomon's seal for forc-ing and retardation culture, different temperatures (forc-ing: 15/5, 20/10, 25/15, and 30/20 ο C, day length 12/12 h) (retardation: 28/18, 32/22, 36/26, and 40/30 ο C, day length 12/12 h) were treated on dormancy broken rhizomes. As the temperature fo...

Photosynthetic characteristics of two Cymbidium hybrids, ‘Red Fire’ and ‘Yokihi’, were investigated at different developmental stages. The net CO2 assimilation rate (A n) as a function of incident photosynthetic photon flux (PPF), intercellular CO2 concentration (C i), and relative humidity (RH) in a leaf chamber head was determined in a greenhouse...

In Korea, slurry composted and biofiltered (SCB) liquid fertilizer is produced through the composting and biofiltering of animal waste. An appropriate guidelines involving proper treatment of SCB liquid fertilizer on turfgrass should be considered. An experiment was conducted to determine the optimum application amount, timing, and frequency of SCB...

has been reported that many spring ephemeral plants have underdeveloped embryos at seed harvest. The seeds with underdeveloped embryos at harvest have morphological (MD) or morphophysiolog-ical dormancy (MPD). This study was conducted to serve basic information for the research of morpholog-ical dormancy of seeds in several ornamental spring epheme...

Jeffersonia dubia (Maxim.) Benth. et Hook. has been recognized as a promising horticultural crop which has attractive light purple flowers and heart-shaped leaves. However, seeds of this Korean endemic have proven to be very difficult to germinate. It takes a long time (about 9 months) for the seeds to germinate due to seed dormancy. For a horticul...

The Ranunculaceae is a family reported to have morphological dormancy (MD) or morphophysiological dormancy (MPD), with rudimentary or linear embryos. Thalictrum rochebrunianum is a perennial plant within the Ranunculaceae family. There are few reports on embryo growth, morphology, and germination in Thalictrum (Ranunculaceae) species. The aims of t...

Dormancy breaking and flowering of Paeonia lactiflora ‘Taebaek’ were controlled by natural cumulative chilling and GA3 treatments according to the transfer date in the central region of Suwon, Korea. Shoot emergence and flowering did not occur throughout the experimental period when dormant rootstocks were transferred to a glasshouse between Septem...

Changes in phytoremediation efficiency after repeated exposures (three) to toluene (1.3 ppm) were assessed in 26 species and two additional cultivars of indoor plants. There was a rapid increase in toluene removal efficiency in 27 of the 28 crops with the greatest increase between the first and second exposure (i.e., after 3 days). The increase in...

Water absorption properties of different wicks were found out, and water diffusion of various irrigation systems was recorded in planters for indoor plants. Microfiber, cotton, and nonwoven fabric were used as wicks, and water diffusion pattern was demonstrated at drip, hand, and wick irrigation system. The height of water absorption was a differen...

This study was conducted to investigate the effect of treatment time and concentration of a chemical pinching agent, dikegulac, on branches and growth of Rhododendron simsii ‘California Sunset’. R. simsii ‘California Sunset’ developed lateral branches naturally but the number of them was few. Treatment of dikegulac delayed the terminal bud developm...

An adventitious rooting of softwood cuttings was evaluated according to leaf number and rooting media in Native Hydrangea serrata for. acuminate. The shoots were carried to the lab in polyethylene bags and were cut to create cuttings of approximately 10 cm length. Softwood cuttings were prepared with 0, 1, 1/2+1/2 or 2 leaves and were planted in fo...