• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.4
• /
• pp.307-314
• /
• 1984

One hundred winter wheat cultivars obtained from the world collections in Korea were planted in 1982. Stomatal frequency of flag leaf of these cultivars were measured, and among these 21 cultivars which showed different stomatal frequency were selected to investigate the relationship of their stomatal frequencies and other characters such as culm length, heading date and characters related to leaf. Stomatal frequency of flag leaf of 100 cultivars different significantly, ranging from 51 to 90 stomata mm$^{-2}$ for the adaxial and 35 to 65 for the abaxial surfaces of leaf. Stomatal frequency was always greater on the adaxial than on the abaxial surface. Mean ratios (adaxial/abaxial) were 1.5 for the flag leaf and 1.3 for the from second to fouth leaves. Among 21 cultivars examined, stomatal size which measured guard cell length varied from 38.5 to 46.6$\mu$ for adaxial surface and from 39.4 to 49.4$\mu$ for abaxial. A negative correlation was obtained between stomatal frequency and its size. Stomatal frequency decreased from flag (L$_1$) to lower leaves, progresively. Stomatal frequency on L$_1$ sheath was compared to those on L$_3$ and L$_4$ abaxial surface of leaf. More stomatal frequency on top and center of adaxial surface showed than that on basal part of a leaf but the abaxial surface resulted in reverse of adaxial one. Cultivars with high stomatal frequency on flag leaf showed higher stomatal frequency on the other leaves and sheaths. Positive correlation between stomatal frequency and other characters such as, culm length, heading date and chlorophyll content showed statistical significance, whearas it revealed the negative correlation of stomatal frequency with leaf weight, leaf area and stomatal aperture. However, no relation appeared between stomatal frequency and leaf vein.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.4
• /
• pp.266-275
• /
• 1997

Anemarrhena asphodeloides BUNGE is one of important medicinal crops, which has been collected or/and cultivated for its rhizomes. The main medicinal ingredient of the A. asphodeloides Bunge rhizomes is a saponin, which is known to have medical values for diaphoresis, sedatives and biuresis. However, studies on cultural methods and breeding works on this plant have not been made in detail. To increase productivity and to improve quality of crops, it is important to collect cultivated and wild lines, to classify them based on morphological and genetic characteristics, and to select superior pure lines at first. Therefore, total 20 A. asphodeloides lines collected were cultivated at the fieldof Chungnam Provincial Administration of Rural Development in 1995 to study the agronomic characteristics and to classify them based on morphological characteristics. Characteristics related with reproductive organ such as the number of spikes per plant and peduncle length showed greater variations than vegetative organrelated characteristics such as leaf length and rhizome length based on the coefficient of variation. Vigorous shoot growth resulted in better development of reproductive organs such as peduncle length and number of spikes per plant. However, the development of spikes was negatively correlated with chlorophyll content. Characteristics of underground parts were more significantly correlated with spike characteristics than aerial part characteristics. A. asphodeloides tested in this study were classified into 2 groups (group A and group B) based on centroid linkage cluster analysis. Group A showed more vigorous shoot growth with more leaves and spikes per plant, longer peduncle length, thicker peduncle diameter and higher shoot dry weight than group B. Group A could be further classified into 2 sub-groups based on leaf size, spike length and peduncle diameter, while group B also could be classified based on number of leaves, number of spikes and shoot dry weight.

• Research in Plant Disease
• /
• v.25 no.3
• /
• pp.136-142
• /
• 2019

Drought stress is considered as one of major abiotic stresses; it leads to reduce plant growth and crop productivity. In this study, we selected bacterial strains for alleviating drought stress in chili pepper plants. As drought-tolerant bacteria, 28 among 447 strains were pre-selected by in vitro assays including growth in drought condition with polyethylene glycol and plant growth-promoting traits including production of 1-aminocyclopropane-1-carboxylate deaminase, indole-3-acetic acid and exopolysaccharide. Sequentially, 7 among pre-selected 28 strains were screened based on relative water content (RWC); GLC02 and KJ40, among seven strains were finally selected by RWC and malondialdehyde (MDA) in planta trials under an artificial drought condition by polyethylene glycol solution. Two strains GLC02 and KJ40 reduced drought stress in a natural drought condition as well as an artificial condition. Strains GLC02 or KJ40 increased shoot fresh weight, chlorophyll and stomatal conductance while they decreased MDA in chili pepper plants under a natural drought condition. However, two strains did not show biocontrol activity against diseases caused by Phytophthora capsici and Xanthomonas campestris pv. vesicatoria in chili pepper plants. Taken together, strains GLC02 or KJ40 can be used as bio-fertilizer for alleviation of drought stress in chili pepper plants.

• Journal of agriculture & life science
• /
• v.53 no.6
• /
• pp.13-21
• /
• 2019

The influences of light generated by LEDs on shoot growth and photosynthesis of Tea plant(Camellia sinensis L.) were evaluated. The growth characteristics were investigated after 45 days of culture under four different light qualities: fluorescent lamp, red LED, blue LED, red+blue+white LED. Shoot growth was promoted by red light, especially root length and area were further promoted under the red+blue+white LED. Also, T/R ratio and Chlorophyll content were highest in red+blue+white. Fluor Cam was used to measure the fluorescence images of the plants, inhibition of photochemical efficiency(Fv/Fm) were not changed in all treatment. However, non-photochemical quenching(NPQ) were found rapidly increasing in blue LED, these results were that blue LED were inhibit photosynthetic efficiency and must be considered for efficiently in vitro cultivation of the tea plant. The above results suggest that light qualities could be an important factor to foster in vitro growth of the species. Also, In order to produce healthy plants, it is effective to using light qualities of red+blue+white LED on in vitro culture of the tea plant. These results could be used to mass propagating shoot and produce of healthy seedling.

• Horticultural Science & Technology
• /
• v.29 no.6
• /
• pp.617-622
• /
• 2011

The study was conducted to determine the efficiency in producing spontaneous polyploids in some mandarin hybrids with different seed embryony. Seed formation by open pollination, frequency of spontaneous polyploids, and plant growth characteristics were evaluated in four mandarin hybrids with polyembryony such as 'Amakusa', 'Haruka', 'Hayaka', and 'Seminole' and two with monoembryony such as 'Benibae' and 'Harehime'. The mean number of the developed seeds per fruit was 10.0 and frequency of small seeds was 25.1%. Polyploids were selected from plants germinated in vitro by a flow cytometry and confirmed by chromosome analysis. One triploid was produced from 'Harehime', one tetraploid, 'Amakusa', and one tetrapoid, 'Benibae'. There were little differences in leaf shape, thickness, petiole length, and internode length between diploids and polyploids such as tri- or tetraploid. However, polyploids had larger stomata and lower density of stomata in abaxial epidermis than diploids. SPAS indicating chlorophyll content and photosynthetic rate were significantly affected by ploidy level. The results indicated that spontaneous polyploids might be produced by open pollination in some mandarin hybrids and monoembryony had higher frequency in polyploid occurrence than polyembryony.

• The Korean Journal of Malacology
• /
• v.15 no.1
• /
• pp.21-30
• /
• 1999

This study was carried out to describe the growth of Ruditapes philippinarum on Chohwa and Toksan tidal flat in Kwangyang Bay, from June 1994 to July 1995. On the Chohwa tidal flat, the mean gran size, organic content and chlorophyll-a of the surface sediment were the range of 2.50-4.46 , 4.99-5.11%, 14.53-19.90 $\mu\textrm{g}$ cm$\^$-3/, and on the Toksan tidal flat, 0.83-1.66 , 2.22-2.34%, 6.20-6.90 $\mu\textrm{g}$ cm$\^$-3/, respectively. The shell length of R. philippinarum increased rapidly from spring to summer, and gently from summer to autumn, and ceased during winter. Fresh weight increased during spring and autumn, and decreased during summer and winter. condition factors also showed the same variations of weights. Synthesized annual growth pattern of 4 year classes in shell length fitted the von Bertalnffy growth model well. The annual growth of weight fitted the Gompertz model relatively well. The values of w, initial shell growth rate, and AGR$\sub$max/, maximum weight growth rate, on the Chohwa tidal flat were lower than those on the Toksan tidal flat. Comparing the growth patterns in the same tidal flat, growth rate was higher on the lover tidal flat than those on the higher tidal flat. In conclusion, the Chohwa tidal flat maintaining higher density showed lover growth rate, because of relatively insufficient food supply and inhabiting space.

• Journal of Bio-Environment Control
• /
• v.26 no.3
• /
• pp.208-214
• /
• 2017

This study aimed to determinate the effect of fluorescent light and light-emitting diodes on the leaf morphology, growth and antioxidant capacity of Salvia plebeia. The plants were grown for 56 days after transplanting (DAT) under the fluorescent light (FL) and LEDs (White, Red and Blue (R+B, ratio 2:1), Blue, Red LED) under the same light intensity and photoperiod ($130{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 hours). Leaf length, width and number of Salvia plebeia at the 56 DAT were significantly higher under the FL and red LED, and lower in the RB LED and white LED. The highest fresh and dry weights of shoot and leaf area were observed in the red LED, followed by the FL and blue LED, and the lowest in the RB LED and white LED. After 21 DAT, leaf apinasty symptom was appeared in plants grown under red LED and RB LED. The chlorophyll content was lower in the red LED. The specific leaf weight, the ratio of leaf dry weight to area, was higher in the blue LED, and lowest in the FL. No significant difference in DPPH radical scavenging activity of Salvia plebeia under the different light sources. All the integrated results suggest that the FL light is a proper light conditions for a closed cultivation of Salvia plebeia.

• Journal of Korean Society of Forest Science
• /
• v.89 no.1
• /
• pp.65-76
• /
• 2000

Lichen flora of 'Backwoon' mountain, Korea, was investigated during the summer of 1998 and 1999 to screen out lichen species which can be used as a biomonitor for atmospheric ozone. The identified foliose or fructicose lichens in the area were classified into 9 families, 20 genera and 34 species. The dominant lichen species in the area were found to be Leptogium sp., Parmelia sp., Parmotrema sp., Phaeophyscia sp. and Cladonia sp. It was also found that lichen species showing a wide range of sensitiveness to air pollution were distributed in 'Backwoon' mountain. The Parmotrema austrosinense, P. tinctorum, Certrelia braunsiana and Ramalina yasudae collected in the area were exposed to ozone at the level of 200ppb, 8hr/day in controlled growth chamber for 2 weeks. Malondialdehyde(MDA), hydroperoxy conjugated dienes(HPCD), soluble protein content and OD435nm/OD415nm ratio for phaeophytinization of chlorophyll were measured and a pollution index(PI) was calculated for each lichen. Ozone exposure severely damaged to the lichens in the order of P. austrosinense>P. tinctorum>C. braunsiana>R. yasudae. P. austrosinens easily identified and widely distributed in Korea is likely to be a very useful biomonitor of air pollution, especially for ozone. These results indicate that Korean lichen species can be used as a biomonitor for air pollution to evaluate air quality contaminated with ozone.

• The Plant Pathology Journal
• /
• v.34 no.4
• /
• pp.316-326
• /
• 2018

The effect of simulated climate changes by applying different temperatures and $CO_2$ levels was investigated in the Blumeria graminis f. sp. tritici/wheat pathosystem. Healthy and inoculated plants were exposed in single phytotrons to six $CO_2$+temperature combinations: (1) 450 ppm $CO_2/18-22^{\circ}C$ (ambient $CO_2$ and low temperature), (2) 850 ppm $CO_2/18-22^{\circ}C$ (elevated $CO_2$ and low temperature), (3) 450 ppm $CO_2/22-26^{\circ}C$ (ambient $CO_2$ and medium temperature), (4) 850 ppm $CO_2/22-26^{\circ}C$ (elevated $CO_2$ and medium temperature), (5) 450 ppm $CO_2/26-30^{\circ}C$ (ambient $CO_2$ and high temperature), and (6) 850 ppm $CO_2/26-30^{\circ}C$ (elevated $CO_2$ and high temperature). Powdery mildew disease index, fungal DNA quantity, plant death incidence, plant expression of pathogenesis-related (PR) genes, plant growth parameters, carbohydrate and chlorophyll content were evaluated. Both $CO_2$ and temperature, and their interaction significantly influenced powdery mildew development. The most advantageous conditions for the progress of powdery mildew on wheat were low temperature and ambient $CO_2$. High temperatures inhibited pathogen growth independent of $CO_2$ conditions, and no typical powdery mildew symptoms were observed. Elevated $CO_2$ did not stimulate powdery mildew development, but was detrimental for plant vitality. Similar abundance of three PR transcripts was found, and the level of their expression was different between six phytotron conditions. Real time PCR quantification of Bgt was in line with the disease index results, but this technique succeeded to detect the pathogen also in asymptomatic plants. Overall, future global warming scenarios may limit the development of powdery mildew on wheat in Mediterranean area, unless the pathogen will adapt to higher temperatures.

• Journal of Korean Society of Forest Science
• /
• v.100 no.2
• /
• pp.212-217
• /
• 2011

A photoautotrophic micropropagation methodology in liquid culture medium has a number of advantages for large-scale propagation of plants. This paper describes an improved system for the mass propagation via somatic embryogenesis of the medicinal plant Kalopanax septemlobus Nakai. Somatic embryo-derived young plantlets of K. septemlobus were cultured either under heterotrophic conditions with sucrose on half-strength MS medium with $30gL^{-1}$ sucrose, under heterotrophic conditions without sucrose, or under photoautotrophic conditions (MS liquid medium without sucrose under forced aeration) for four weeks before transferring the plantlets for acclimatization. Plantlets grown under photoautotrophic conditions had more leaves, higher chlorophyll content, a higher net photosynthetic rate (NPR), and a higher survival rate. The results indicate that the photoautotrophic conditions with a forced ventilation system are effective in enhancing the growth of plantlets and the rate of net photosynthesis. The plantlets grown under photoautotrophic conditions had a high survival rate (92%) upon ex vitro transplantation. Our study shows that autotrophically produced plantlets acclimatize better and sooner upon ex vitro transplantation than conventionally cultured plants.