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To produce nylon 6,6 (N66)-based composites with carbon fiber (CF) having extremely high mechanical strength, CF covalently bonded with carbon nanotube (CNT), CF–c–CNT, was first produced by reacting functionalized CF and CNT and then a composite of N66 and CF–c–CNT was produced by melt extrusion. Two types of CF–c–CNT were prepared: CF and CNT functionalized with acyl chloride (COCl) and amine group (NH2), respectively (COCl–CF–c–CNT–NH2), and CF and CNT functionalized with NH2 and COCl, respectively (NH2–CF–c–CNT–COCl). N66 bonding to CF–c–CNT occurred during extrusion by the reaction of COCl with amine groups in N66. Thus, N66 bonded to CF (N66–CF–c–CNT) and N66 bonded to CNT (CF–c–CNT–N66) were formed. The N66/CF–c–CNT–N66 composite exhibited the highest interfacial adhesion, the best filler dispersion, and the greatest amount of N66 bonding to filler among the composites tested. As a result, the N66/CF–c–CNT–N66 composite had the highest tensile strength and fatigue life among the composites. The tensile strength and fatigue life of the N66/CF–c–CNT–N66 composite were 20% higher and five times longer than those of the N66/CF composite, respectively.

This study aimed to clarify the germination characteristics and seed dormancy type of three Rhododendron species (R. brachycarpum, R. micranthum, and R. mucronulatum var. ciliatum) native to Korea. The embryos of three Rhododendron species were linear and fully developed, indicating the absence of morphological dormancy (MD). R. brachycarpum and R. micranthum had non-dormant (ND) seeds at dispersal, whereas R. mucronulatum var. ciliatum seeds had some physiological dormancy (PD) at population level. The application of exogenous gibberellic acid (GA3) at 1,000 mg･L-1 broke the PD of R. mucronulatum var. ciliatum, while cold stratification at 4°C had no effect on seed dormancy. The optimal environmental conditions for seed germination were light･ 25/15°C for R. brachycarpum, darkness･20/10°C for R. micranthum, and light·25/15°C for R. mucronulatum var. ciliatum. Due to the interspecific variation of Rhododendron genus, the seed dormancy type or germination characteristics of all species were distinguished in this study. This study could be useful to understand the ecophysiological characteristics of Rhododendron species native to Korea.

The growth and flowering characteristics of four Korean Veronica species (V. dahurica, V. kiusiana var. diamantiaca, V. pusanensis, V. pyrethrina) were evaluated under various shading levels. Among the study species, V. kiusiana var. diamantiaca has been designated as both an endemic and a rare species (critically endangered) in Korea. V. pusanensis has been designated as both a rare species (data deficient) and an endemic species, as they exist only in Busan, Korea. This study was conducted from March 30 to August 17, 2018 in an experimental plot at the Korea National Arboretum. The study species were cultivated under 0%, 40%, 60%, and 90% shading levels. The fresh shoot weight, number of leaves, and number of branches of V. dahurica grown under 0% – 60% shading levels was significantly higher than when grown under the 90% shading level. The stem caliper of V. pyrethrina grown under 0% – 60% shading levels was significantly higher than under the 90% shading level. V. dahurica and V. pyrethrina grown under 0%, 40%, and 60% shading levels were flowered. Also, time to flowering of V. dahurica and V. pyrethrina grown under 0%, 40%, and 60% shading levels were shorter than when grown under the 90% shading level. The dry weight of the shoots and the visual quality of the kiusiana var. diamantiaca grown under 0% – 40% shading levels were significantly higher than under the 60% – 90% shading levels. The visual quality of V. pusanensis grown under 0%, 40%, 60%, and 90% shading levels were 4.0, 3.0, 2.2, and 1.0, respectively. These results indicate that the four studied Veronica species have different sensitivities to light intensity.

Nitrogen-doped holey carbon nanotubes (N-HCNTs) were fabricated for use as a cathode material of Zn–air batteries. Holes were formed in the carbon nanotube (CNT) by reacting it with hydrogen peroxide, following which the oxidized CNT was pyrolyzed with urea to form N-HCNT. The electrocatalytic activities of N-HCNT in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) were compared with those of Pt/C and IrO2; N-HCNT exhibited excellent bifunctional electrocatalytic activity in both, the ORR and OER, while Pt/C and IrO2 exhibited excellent electrocatalytic activity only in the ORR and OER, respectively. Further, the maximum power density of a Zn–air rechargeable battery using the N-HCNT electrode was 17.6% higher than that of a battery using a mixture of Pt/C and IrO2 (1:1) as the electrode. Moreover, after 500 cycles, the change in the charge-discharge voltage gap of the battery using the N-HCNT electrode (18.3%) was much smaller than that of the battery using the mixture of Pt/C and IrO2 (118.1%). The excellent electrocatalytic activity and cycle life of the N-HCNT electrode in Zn–air battery demonstrate its promise in the development of future energy devices.

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. V. sibiricum seeds were permeable to water and had a mature embryo during seed dispersal. In field conditions, germination was prevented by physiological dormancy, which was, however, relieved by March of the next year, allowing the start of germination when suitable environmental conditions occurred. In laboratory experiments, the seeds treated with 0, 2, 4, 8, and 12 weeks of cold stratification (4 °C) germinated to 0, 79, 75, 72, and 66%, respectively. After the GA3 treatment (2.887 mM), ≥90% of the seeds germinated during the four incubation weeks at 20/10 °C. Thus, 2.887 mM GA3 and at least two weeks at 4 °C were effective in breaking physiological dormancy and initiating germination. Therefore, the V. sibiricum seeds showed non-deep physiological dormancy (PD). Previous research, which determined seed dormancy classes, revealed that Veronica taxa have PD, morphological (MD), or morphophysiological seed dormancy (MPD). The differences in the seed dormancy classes in the Veronicastrum-Veronica clade suggested that seed dormancy traits had diverged. The results provide important data for the evolutionary ecological studies of seed dormancy and seed-based mass propagation of V. sibiricum.

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, and 25 °C) and gibberellic acid (GA3) concentrations (0, 10, 100, or 1000 mg/L) on seed dormancy and germination of E. jolkinii. In addition, we classified the seed dormancy type and compared types with those of other species in the same genus. Results The number of seeds with viable embryos and endosperms was approximately 66%. The final germination percentages at 5, 15, 20, and 25 °C were 51.7%, 83.5%, 2.6%, and 0.0%, respectively. In GA3 concentration experiments, the final germination percentages of 0, 10, 100, and 1000 mg/L were 83.5%, 91.7%, 79.1%, and 83.4%, respectively, at 15 °C conditions, and 0.0%, 6.9%, 13.2%, and 27.3%, respectively, at 25 °C. Conclusions Germination improved at temperatures of 15 °C or lower. Furthermore, GA3 treatment effectively reduced germination times. Thus, the seeds of E. jolkinni were classified as having non-deep physiological dormancy.

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. venusta and H. yingeri) grew inside the seeds prior to germination (i.e., were underdeveloped) or did not do so (i.e., were fully developed). Our second purpose was to identify the class of dormancy found in these seeds by examining germination during incubation at 15 and/or 25°C. The initial embryo : seed ratio in seeds of the six Hosta species was between 0.78 and 0.85, and embryos elongated by 9.6 to 17.5% prior to germination. Seeds of H. capitata, H. clausa, H. venusta and H. yingeri germinated to ≥65% in light and darkness at 15 and 25°C within 30 days, those of H. minor germinated to ≥80% in light and darkness at 25°C and to 24% in light and 50% in darkness at 15°C, and those of H. jonesii germinated to 100% in light at 25°C. We conclude that embryos in seeds of these six Hosta species are underdeveloped at maturity. Because high percentages of H. capitata, H. clausa, H. venusta and H. yingeri seeds germinated at cold and warm temperatures within 30 days, they have MD. On the other hand, seeds of H. minor germinated to high and low percentages at warm and cold temperatures, respectively. Thus, some seeds have MD and others may have MPD.

This study aims to examine the effects of cold durations and photoperiods on dormancy break, growth, and flowering of Patrinia rupestris native to Korea. First, we monitored the growth and flowering phenology of plants growing in an open field from March to October, 2018. For the dormancy breaking experiments, P. rupestris was maintained at 4°C for 0, 3, 6, 9, and 12 weeks under short-day conditions andfor cold treatment. The plants were then transferred to long-day conditions (9 h + 4h night interruption) in room chamber set at 25°C. To determine photoperiodic responses, P. rupestris was maintained under short- (9 h, SD), middle- (12 h, MD), and long-day (16 h, LD) conditions in room chamber set at 25°C following natural chilling accumulation. In open field conditions, P. rupestris blooms in the late summer from August to September with attractive yellow flowers. Time to first flower significantly decreased following 9 or 12 weeks of cold storage compared with the plants subjected to 3 or 6 weeks of cold storage. P. rupestris required ≥9 weeks of chilling treatment to achieve ≥33% flowering. Plant height was the highest in the LD condition (50.1 cm) compared with the SD (16.7 cm) and MD (16.1 cm) conditions. All plants grown under LD conditions flowered, but not all plants grown under SD and MD conditions did (0% flowering) after 16 weeks of forcing. P. rupestris demonstrated both obligate vernalization and long-day flowering responses.

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 Asarum sieboldii, an East Asian species, based on a phenology study and experiments in controlled temperature conditions, and then compared it to that of the previously studied A. canadense, an eastern North American species. The underdeveloped embryo of A. sieboldii grew and germinated (radicle emergence) in autumn but shoot emergence did not occur until the following spring. The seeds of A. sieboldii had deep simple epicotyl morphophysiological dormancy because the seeds with emerged radicle required a relatively long period of cold stratification to break epicotyl dormancy and produce a shoot. Although the seed of A. sieboldii had weaker radicle dormancy and stronger epicotyl dormancy compared to A. canadense, the kind of seed dormancy was the same for the two species. The trait of seed dormancy was inherited from a shared common ancestor and maintained in populations well after the two species (or their ancestors) separated. However, quantitative differences in temperature requirements for radicle and shoot emergence suggest the possibility of adaptation to the environment.

In this letter, we propose the objective metric that can precisely predict the perceptual quality of contrast-changed images using inter-pixel contextual information. The metric consists of two parts. One is a two-dimensional (2-D) histogram-based contrast quality measure that utilizes the distribution of the gray-level differences between adjacent pixels. We design the desired 2-D histogram considering the characteristic of an adequately high contrast image and predict contrast quality by comparing the desired 2-D histogram with 2-D histograms of an original image and a contrast-changed image. The other is a spatial entropy based one that uses the information of spatial location distribution of gray-levels. A comparison is carried out with many IQA metrics on five contrast related databases. Experimental results show that the proposed metric provides a more accurate prediction of human perception of contrast change than other metrics.

Euphorbia jolkinii Boiss. is a perennial herb belonging to the family Euphorbiaceae and is native to Jeju island and the southern coastal area of Korea. It holds potential as a new ornamental plant, with yellow-green flowers and a long flowering period which ranges from March to May. The present study aimed to investigate the population distribution and growth environments in habitats that are native for the species. Identification of 14,817 plants was done at more than 40 sites along the coastal area of Jeju Island. Of these, 1,075 individuals (7.3%) were identified in eastern Udo, 952 individuals (6.4%) were found in north-west Biyangdo, and 589 individuals (4.0%) were identified in southern Gapado. E. jolkinii was found mainly occurring on rocky areas of the southeastern coast. Similarly, it was distributed only in the eastern part of the island i.e., in the areas of Gapado, Udo, and Biyangdo. The growth of E. jolkinii varied depending on its native area. Plant height, stem length, and stem caliper showed positive correlation with flower size. In each area, flowers bloomed in late March, and seeds were dispersed starting in early June. Approximately 30 plant species were distributed in the vegetation surrounding E. jolkinii habitats, including Spergularia marina (L.) Besser, Rosa wichuraiana Crep. ex Franch. & Sav., Vitex rotundifolia L.f., and Angelica japonica A. Gray. Herbaceous and woody plants accounted for 80% and 20%, respectively. Soil pH ranged from 8.3 to 9.4, and salinity values obtained ranged from 0.003 to 0.017%. Organic matter was determined to be present at 1.9% in Jungmun, 1.4% in Gapado, and 1.0% in Pyoseonmyeon, and cation exchange capacity (CEC) values were recorded as 10.7 cmol+/kg in Gapado, 5.6 cmol+/kg in Pyoseonmyeon, and 1.3 cmol+/kg in Jungmun, respectively. Electrical conductivity (EC) was determined to be 0.47 dS/m in Jungmun, 0.19 dS/m in Gapado, and 0.16 dS/m in Pyoseonmyeon, and Cl− was 57.45 mg/kg, 63.01 mg/kg, and 8.12 mg/kg, respectively. Available phosphate was not detected in the coastal areas of Jungmun.

A novel image enhancement method for infrared (IR) images is presented. The proposed method consists of two parts considering the characteristics of high-dynamic-range IR images. First, we attempt to enhance image contrast by introducing the ramp distribution that increases with a constant slope in an ordered histogram domain. The ramp-distributed histogram is incorporated into an optimization problem with a sorted histogram of the input image to calculate a modified histogram. Second, to deal with blurred effects on IR images, we propose a relative edge-strength index for high-boost filtering to effectively suppress noise in relatively uniform regions. Compared with various conventional and state-of-the-art algorithms, the proposed method shows highly competitive performance.

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-3-butyric acid (IBA). The stem cuttings pretreated with 2685, 5370 µM NAA or 4920 µM IBA displayed the best rooting traits; the rooting percentage, number of adventitious roots, length of roots, and fresh weight of roots. It would be advisable to use the lower concentration, for economy in using the hormone. We recommend treating cuttings with 2685 µM NAA for the propagation of P. rupestris to produce large amounts of planting materials.

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 field conditions, the seeds were buried in field soil. Every 1 or 2 weeks, the seeds were exhumed, and embryo growth, germination, and seedling emergence were investigated. In the laboratory, the effects of temperature and GA3 on dormancy break and germination were investigated in order to characterize the seed dormancy. The seeds had underdeveloped embryos that were physiologically dormant at maturity in late September. In natural conditions, embryo growth and germination occurred in March of the following year, and seedlings emerged in early April. The physiological dormancy of the embryos was broken by cold stratification at 5 °C for 8 weeks, but warm temperatures (25/15 °C) were required to promote embryo elongation even after the physiological dormancy was broken. GA3 treatment could substitute for the cold stratification requirements and broke seed dormancy of T. uchiyamae, 87.3% of which germinated after 8 weeks of incubation at 25/15 °C at 100 mg ⋅L−1 GA3 soaking treatment. These results suggest that the seeds of T. uchiyamae exist in a state of non-deep simple morphophysiological dormancy. The temperature requirements for the dormancy break of the seeds enabled the seedlings to emerge in the very beginning of the growing season the following year. These results represent practical knowledge for propagation of these plants from seed.

Heavenly bamboo ( Nandina domestica ) is a popular ornamental shrub used as an indoor plant and for landscaping. However, seed propagation has been limited due to its very slow germination (9 months under natural conditions) caused by an extended seed dormancy period. We used various temperature treatments, including simulations of seasonal temperature changes, to investigate the temperature requirements for dormancy breaking and the germination of heavenly bamboo seeds at the embryo and whole-seed levels. Heavenly bamboo seeds were found to have no physical dormancy because the seeds imbibed water readily. However, its mature seeds contained underdeveloped embryos (E:S ratio 3 ) at 100 and 1000 mg L −1 could substitute for warm stratification and broke dormancy in seeds incubated at 15/6 °C. These results suggested that heavenly bamboo seeds had non-deep simple morphophysiological dormancy, which could be broken by warm stratification at 25/15 or 20 °C.

Multiwalled carbon nanotubes (MWCNTs) with physically absorbed pyrene derivatives containing a hydroxyl group are investigated as an effective filler for polybutylene terephthalate (PBT) composites. During extrusion, transesterification reaction occurred between the hydroxyl group of 1-pyrenebutanol (PBOH) and ester group of PBT, thereby grafting PBT onto MWCNTs. Reactions between PBT and 1-hydroxypyrene (POH) and 1-pyrenemethanol (PMOH) absorbed onto the MWCNTs were also observed. Compared to the POH and PMOH absorbed MWCNTs, the higher amount of PBT was grafted onto PBOH absorbed MWCNTs (PBOH-MWCNTs). Calculation results using the density functional theory suggest that the reactivity of PBT was higher with PBOH than that with POH and PMOH, due to the lowest free energy change at the rate determining step and most stable intermediate formation at the rate determining step for PBOH. PBT/PBOH-MWCNT composite exhibited the highest tensile strength and fatigue life. The highest reactivity of PBT with PBOH among the pyrene derivatives resulted in the greatest amount of PBT grafting onto the PBOH-MWCNTs, best interfacial adhesion between PBT and the PBOH-MWCNTs, and highest mechanical reinforcement in the PBT/PBOH-MWCNT composite.

Epimedium species are shade-tolerant perennials with flowers and leaves that vary in color, making them valuable groundcover plants. We investigated the dormancy of E. koreanum seeds and their requirements for embryo growth and germination. First, the phenology of embryo growth, germination, and seedling emergence under field conditions were observed. Then, the effects of temperature sequences and gibberellic acid (GA3) treatment on dormancy and germination were evaluated in two laboratory experiments. Under field conditions, the underdeveloped embryos grew very little from June to early September, while rapid growth of the embryos was observed from late September to November. Embryo growth was completed by early December, resulting of 16-fold increase of the initial length of the embryo. The seeds had germinated in March of the following year, and the germination percentage reached 84.4 %. In the laboratory experiments, embryos hardly grew when the seeds were incubated at a constant temperature of 20 or 15 °C. When the seeds were warm stratified at 25 °C and then moved to lower temperatures of 20 and 15 °C, the embryo grew rapidly. Germination then occurred after cold stratification at 5 °C for 12 weeks. However, if seeds were subjected to cold stratification first, the embryo did not grow, and no seeds germinated. GA3 treatment increased embryo growth in the seeds, but few seeds germinated less than 10 %. Based on these results, seed dormancy of E. koreanum can be broken through warm followed by cold stratification. Therefore, the seeds can be classified as having deep simple morphophysiological dormancy. This is the first report of the ecophysiology of seed dormancy and germination in the genus Epimedium in the Korean peninsula.

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, and 12 weeks (wk). After cold treatment, plants were grown under five different photoperiods [9/15, 12/12, 14/10, 16/8, and 24/0 (day/night) h] for 15 weeks. Plants without cold treatment did not flower throughout the experimental period. However, after a 6-wk cold treatment, percent flowerings were 83 % and 82 % under 16/8 and 24/0 h photoperiods, respectively, and after 9- and 12-wk cold treatments both were 100 %. In Expt. 2, growth stages were divided into two groups according to the number of leaves: Stage 1 (4–6 leaves) and Stage 2 (10–12 leaves). Cold treatment was administered for 0-, 5-, and 10-wk at 5℃ with the same photoperiod treatments as Expt. 1. Flowering was not induced with cold treatment in Stage 1 for any photoperiod treatment. However, in Stage 2, percent flowerings were 40 % and 47 % after 5-wk cold treatments and 71 % and 91 % after 10-wk cold treatments under 16/8 and 24/0 h, respectively. These results indicate that a long-day photoperiod and sufficient cold exposure are necessary for flowering induction of L. mauritiana. This species also requires an appropriate growth stage to sense the forcing conditions.

A good contrast enhancement (CE) algorithm should not only have good performance but also be computationally efficient for real time display. In this paper, we propose a novel efficient CE algorithm, which applies adaptive thresholding based on the slope obtained from a sorted histogram of the input image. The algorithm allows to control levels of perceived contrast. Compared with state-of-the-art CE algorithms, the proposed algorithm shows highly competitive performance with real-time speed.

We performed deep sequencing of target genes in head and neck squamous cell carcinoma (HNSCC) tumors to identify somatic mutations that are associated with induction chemotherapy (IC) response.Patients who were diagnosed with HNSCC were retrospectively identified. Patients who were treated with IC were divided into two groups: good responders and poor responders by tumor response and progression-free survival. Targeted gene sequencing for 2404 somatic mutations of 44 genes was performed on HNSCC tissues. Mutations with total coverage of500 were excluded, and the cutoff for altered allele frequency was10 %.Of the 71 patients, 45 were treated upfront with IC. Mean total coverage was 1941 per locus, and 42.2 % of tumors had TP53 mutations. Thirty-three mutations in TP53, NOTCH3, FGFR2, FGFR3, ATM, EGFR, MET, PTEN, FBXW7, SYNE1, and SUFU were frequently altered in poor responders. Among the patients who were treated with IC, those with unfavorable genomic profiles had significantly poorer overall survival than those without unfavorable genomic profiles (hazard ratio 6.45, 95 % confidence interval 2.07-20.10, P0.001).Comprehensive analysis of mutation frequencies identified unfavorable genomic profiles, and the patients without unfavorable genomic profiles can obtain clinical benefits from IC in patients with HNSCC.

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 weeks, the seeds were exhumed, and the phenology of embryo growth, germination and seedling emergence were investigated. In the laboratory, effects of temperature and GA3 treatment on embryo growth and germination were also investigated to characterize the type of seed dormancy. Seeds had underdeveloped embryos, which were about 20% of the size of those in fully matured seeds. In natural conditions, embryo growth and germination occurred in early and late March next year, respectively, and embryos in the seeds of this species had to grow to a critical length before germination was possible. Thus, the seeds had morphological dormancy (MD). When tested at the time of dispersal, few seeds germinated after 4 weeks of incubation at 25/15°C. Therefore, the seed dormancy type for T. rochebrunianum seemed to be morphophysiological. Embryos in the seeds grew rapidly at warm temperature conditions following cold stratification at low temperatures. After 4–12 weeks of cold stratification at 1°C or 5°C, the seeds germinated rapidly during an incubation at 25/15°C. Cold stratification requirements could be substituted by GA3 treatment in seeds of T. rochebrunianum. After 1000 mg·L-1 GA3 treatment, high percentages (≥ 80%) of the seeds germinated after 4 weeks of incubation at 15/6, 20/10, and 25/15°C. Consequently, seeds of T. rochebrunianum could be characterized as expressing non-deep simple morphophysiological dormancy (MPD). The cold stratification requirements for dormancy break enabled the seeds to produce seedlings at the beginning of the growing season in natural conditions.

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 r...

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 flowers or resulted in flower bud abortion. To prevent flower bud abortion, we placed the dormant rootstocks at five pre-chilling treatments for 2 weeks in mid-September and October. The treatment conditions were 0°C for 2 weeks (C0, control), natural chilling in an open field for 2 weeks (NT), pre-chilling at 15°C for 2 weeks (P15), 15°C for 1 week → 10°C for 1 week (P15 → 10), and pre-chilling at 10°C for 2 weeks (P10). After these pre-chilling treatments, all of the plants were placed under a cold regime of 0°C for 6 weeks in order to break dormancy. In the C0 and NT treatments, a great numbers of flower buds were aborted from their stems. On the other hand, the P15 → 10 and P10 treatments increased to 74.7 and 81.0% for flowering, respectively. Pre-cooling treatment accelerated the growth of flower buds compared to the C0 or NT treatments. To promote blooming in the autumn season, rootstocks were also placed into three treatments (C0, NT, and P10) in early July. While the C0 and NT treatment were unable to produce flowering at all, the treatment P10 induced more than 80% flowering of plants. From these results, pre-chilling at treatment 10°C for 2 weeks was recommended as the optimum treatment to promote flowering without flower bud abortion in forcing culture for winter or autumn flowering.

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 shade-preferring plant, no study has determined the optimum light intensity for its growth. The objectives of this work were to observe the effects of various shading levels on the physiological responses of J. dubia and to determine the proper shading level for cultivation. Treatments consisted of four shading levels (0%, 50%, 75%, and 95% shade) imposed using black mesh cloth. The number of leaves and dry weight increased with decreased shading. The shoot-to-root ratio increased with increased shading, mainly due to decreased root dry weight under shading. Plants showed low net CO 2 assimilation rates and F v/Fm values combined with low dry matter levels when grown under 0% shade (full sunlight). These results indicate that J. dubia plants experience excessive irradiance without shading, resulting in damage to the photosynthetic apparatus. By contrast, the net photosynthesis rate increased as the shading level increased. Fv/Fm, the potential efficiency of PSII, was 0.8 under 95% shade, indicating that J. dubia is well-adapted under heavy shading. However, the low dry matter of plants in the 95% shade treatment indicated that the low light intensity under 95% shade led to a decline in plant growth. Thus, moderate light (50% shading) is recommended for cultivating J. dubia without physiological defects.

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. The 3–4 year-old bulbs and > 10 year-old bulbs were used for vegetative bud development and flower bud development, respectively. For natural chilling treatments, the plants were transferred from an experimental field to a growth module every month from September to February. Artificial chilling treatments were applied at 5°C for 0, 2, 4, 8, and 12 weeks in October and November. The cumulative chill unit (CCU) of low temperatures below 5°C was calculated. Flower bud initiation and differentiation in E. japonicum were observed in May, and from June to July, respectively, followed by flower bud elongation in August. Sprouting and bud break did not occur throughout the experiment when dormant bulbs were transferred from September (0 CCU) to November (450 CCU). However, all plants sprouted when the dormant bulbs were transferred after January (1,794 CCU). Prolonged cold storage also promoted sprouting of dormant E. japonicum. No cold storage or 4 weeks (672 CCU) of cold storage at 5°C in October did not induce sprouting and bud break. However, when the dormant bulbs were stored at 5°C for 12 weeks (2,061 CCU) in October, percent sprouting increased to 72.7%. Chilling treatment for 8 weeks (1,483 CCU) or 12 weeks (2,155 CCU) at 5°C in November resulted in 72.7 and 100% sprouting, respectively. In conclusion, at least 1,483–1,794 CCU may be recommended for dormancy breaking in the forcing culture of E. japonicum.

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, morphology, and seed germination in Heloniopsis species. The aims of this study were to investigate embryo growth and seed dormancy, and to determine the type of dormancy exhibited by these species. The effects of incubation temperatures, light conditions, and gibberellic acid (GA₃) on dormancy break and seed germination were tested. Freshly matured seeds of the two species had small embryos that occupied about 9-11% of the length of the endosperm, and which increased by more than 300% in length before radicle emergence, indicating that the embryos are underdeveloped at the time of dispersal. Embryos in the seeds grew under warm temperature regimes (between 25/15℃ and 30/20℃). GA₃ application (tested only in the light) overcame seed dormancy and promoted germination. Approximately 30% of the seeds of H. koreana and approximately 40% of the seeds of H. tubiflora germinated in suitable environmental conditions (light and temperature) within 4 weeks. Therefore, 30-40% of the seeds of the two species exhibited MD, and the rest of the seeds had non-deep simple MPD. Light was found to be one of the critical factors for germination because no seed of either of the two Heloniopsis species germinated under constant dark conditions, and thus, these species have the potential to form a persistent soil seed bank. Understanding these germination requirements will help in development of effective strategies to increase the establishment of seedlings in their native habitat.

Purpose To investigate the clinical utility of targeted next-generation sequencing (NGS) for predicting the responsiveness to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy, we compared the efficacy with conventional sequencing in never-smokers with lung adenocarcinoma (NSLAs). Patients and methods We obtained DNA from 48 NSLAs who received gefitinib or erlotinib for their recurrent disease after surgery. Sanger sequencing and peptide nucleic acid clamp polymerase chain reaction (PCR) were used to analyze EGFR , KRAS , BRAF , and PIK3CA mutations. We analyzed ALK , RET , and ROS1 rearrangements by fluorescent in situ hybridization or reverse transcriptase-PCR and quantitative real-time PCR. After molecular screening, Ion Torrent NGS was performed in 31 cases harboring only EGFR exon 19 deletions (19DEL), an L858R mutation, or none of the above mutations. Results The 31 samples were divided into four groups: (1) responders to EGFR-TKIs with only 19DEL or L858R ( n =15); (2) primary resistance to EGFR-TKI with only 19DEL or L858R ( n =4); (3) primary resistance to EGFR-TKI without any mutations ( n =8); (4) responders to EGFR-TKI without any mutations ( n =4). With NGS, all conventionally detected mutations were confirmed except for one L858R in group 2. Additional uncovered predictive mutations with NGS included one PIK3CA E542K in group 2, two KRAS (G12V and G12D), one PIK3CA E542K, one concomitant PIK3CA and EGFR L858R in group 3, and one EGFR 19DEL in group 4. Conclusions Targeted NGS provided a more accurate and clinically useful molecular classification of NSLAs. It may improve the efficacy of EGFR-TKI therapy in lung cancer.

The anticancer effect of choline kinase (ChK)-siRNA for breast cancer was evaluated using PEGylated liposomes both in vitro and in vivo. The optimal size and zeta-potential of siRNA/liposome complex were achieved using condensing agents of hyaluronic acid (HA) and protamine with weight ratios of (ChK-siRNA+HA+protamine): liposome between 0.05 and 0.0037. Suppression of the expression of ChK-mRNA and the resulting cell growth inhibition by the treatment with ChK-siRNA was the highest when using 2.5 and 5 mol% PEGylated liposomes. A pharmacokinetic study after intravenous injection into mice showed that the area under the curve (AUC) and blood half-life (t1/2, α and t1/2, β ) of ChK-siRNA in 5 mol% PEGylated liposomes were 19 times and 2.2 to 10.5 times higher than that of naked siRNA, respectively. In vivo study showed that PEG-lipo with siRNA exhibited much better tumor growth inhibition and increased survival time than the free siRNA in an MDA-MB-231-bearing xenograft nude mouse model, presumably due to the increased half-life and the passive targeting effect mediated by the PEGylated liposome. The data clearly show that the PEGylated liposome, together with appropriate condensing agents, could serve as an effective delivery system for the ChK-siRNA therapeutics for breast cancer.