• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.39-44
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• 2019

Drought is one of the key limiting factors that adversely affects the growth and productivity of crop plants. For the enhancement of drought tolerance in crop plants, the identification of basic mechanisms of a plant to drought stress is necessary. In this study, we compared physiological and biochemical responses of five local Arundenilla hirta ecotypes to drought stress. These ecotypes were previously collected from various parts of Korean peninsula, including Youngduk, Gunsan, Jangsoo, Jinju-1 and Yecheon. A. hirta plants were exposed to drought stress for 14 and 17 days respectively, followed by re-watering for 3 days. The results showed that the lipid peroxidation (MDA), hydrogen peroxide ($H_2O_2$), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, and proline level were significantly increased while the chlorophyll content was decreased by drought stress in A. hirta leaves. The highest proline content and DPPH scavenging activity were shown in Ecotype of Youngduk with least MDA and $H_2O_2$ levels while the highest MDA and $H_2O_2$ contents, and least proline and DPPH levels were shown in Gunsan, respectvely. These results indicate that the Youngduk is the most tolerant and Gunsan is the most sensitive ecotype among the five different collections. Together, these results provide a new insight of overall physiological responses of A. hirta to drought stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.403-407
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• 1986

The rice leaf color, which was one of main factors to determine application time of fertilizers, was analyzed in visible region, while the distinction of photosynthetic pigments controlling the rice leaf color was separated by T.L.C. The light absorption peaks of ethyl ether extracts of rice leaf blades were occurred in 413, 432, 453 and 662nm. Especially, the maximal light absorption was 432nm in blue and 662nm in red region. The both light absorption ratios (blue to red region) was not greatly different among rice ecotypes, whereas decreasing tendency in increased fertilization was observed. There was a significant negative correlation between the both light absorption ratios and the values of color chart, and the content of chlorophyll in rice leaf blades. The composition ratio of chorophyll was larger than that of carotenoid at heading stage, and the carotenoid was larger than the chlorophyll at 30 days after heading. The composition ratio of chlorophyll among photosynthetic pigments according to rice ecotypes, Japonica x Indica cultivars were larger than Japonica cultivars at heading stage, and Japonica cultivars were larger than Japonica x Indica cultivars at 30 days after heading, while carotene was vice versa.

• The Korean Journal of Ecology
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• v.12 no.3
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• pp.133-144
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• 1989

The morphology and flowering time of two Suaeda japonica populations from different habitats, the creek and the bank of the mudflat in Sorae, were surveyed. And standard transplantation and reciprocal transplantation were carried out to determine whether their characteristics were genetically fixed or not. Also soil sample of these habitats were analyzed. The amounts of loss on ignition, maximum field capacity, total nitrogen, exchangeable calcium and potassium, and soluble phosphorus were found to be significantly different between two habitats. Leaf thickness, leaf width, leaf length, stem height number of branches, and number of seeds were significantly different between plants of two populations. And flowering times of two populations did not overlap. According to the results of transplantation, leaf width, leaf thickness, and flowering times were the same as those at their original habitat. But the stem lenght, leaf lenght, number of branches and unmber of seeds were not. Therefore, the differences in the leaf length, leaf thickness, and flowering time seemed to bo genetically fixed. It were suggested that the creek bank populations of Suaeda japoinica were to be considered as different ecotypes.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.507-512
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• 1998

Molecular analysis has been done for characterization of the interactions between three beet curly top virus (BCTV) strains and two Arabidopsis ecotypes in terms of virus inducible disease symptoms and infectivities. The total DNA was isolated from three tissues (shoot tips, infection origins and roots) of virus infected plants and this DNA was analyzed by quantitatively and qualitatively to elucidate virus movement and symptom development. CTV-Worland infected Col-O and Sei-O showed only symptom shown in hypersusceptible ecotype Sei-O by BCTV-worland was shoot tip stunting. Kinetics of virus DNA accumulation of three different viruses indicated that roots contained more virus DNA than shoot tips or infection origins, and that disease symptom severity was strongly correlated with virus DNA accumulation. These results suggest that the mild and Worland-specific symptoms shown in Sei-O by BCTV-worland are caused by the interactions of host factors provided by hypersusceptible ecotype and viral factors of mild strain.

• Food Science and Preservation
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• v.5 no.2
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• pp.119-122
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• 1998

This study was conducted to blow the effect of postharvest physiological changes on garlic quality according to its ecotypes and storage temperatures. The changes of water, total soluble solids, crude stein, md total fructans were measured and the rates of respiration and sprouting were analyzed during storage at 20$^{\circ}C$ and 30$^{\circ}C$. The decrease of water content and the increase of total soluble solids were reversely appeared during garlic storage. The crude protein content was gradually increased during storage but total fructan content was decrased. The respiration late was maximized at 60days after storage and the spouting rate was gradually increased. In the aspect of ecotypic characteristics, the water content, fructan content and sprouting rate were higher in 'Namdo' cultivar than those of southern type. The high storage temperature (30$^{\circ}C$) controlled spouting and loss of fructan, and it was effective to maintain the garlic quality.

• Korean Journal of Plant Taxonomy
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• v.51 no.2
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• pp.176-180
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• 2021

Arabidopsis thaliana (L.) Heynh. is a small plant species that serves as a model organism of plant biology and genetics. Here, we present the first complete mitochondrial genome of Korean A. thaliana natural isolate (named as 180404IB4), which is 368,875 bp long and contains 58 genes (33 protein-coding genes, 22 tRNAs, and three rRNAs), with a GC ratio of 44.8%. Sixty-four single-nucleotide polymorphisms and 11 insertion and deletion regions (1,089 bp in length) are identified against the Col-0 ecotype, showing one large insertion of 1,069 bp without structural variation. Phylogenetic trees constructed from 30 conserved genes indicate that the 180404IB4 mitochondrial genome is clustered with Col-0 and three East Asian ecotypes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.265-272
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• 2002

Forage breeding laboratory of National Livestock Research Institute, R.D.A. has made interspecific hybrids of Lolium multiflorum $\times$ L. pratensis and intergeneric hybrids of Lolium $\times$ Festuca since 1984, and has collected ecotypes of Italian ryegrass since 1991. Growth characteristics of these hybrids and ecotypes were researched, and then these clone lines were named. Among these clone lines, the several clones that have polen fertility, high cold-tolerance, and similar heading time were used for making synthetics, Naehan 6, 7, 8, 9, with polycrossing method in 1997. Field experiments were carried out to compare the mophological and agronomical characteristics and forage productivity and quality of the synthetics with those of Italian ryegrass varieties, Barmultra and Hwasan 101. in Suwon and Yonchun from 1999 to 2000. Heading time of the synthetics were 22th to 24th May that belong to late-mature types to be similar to that of Barmultra and Hwasan 101 in Suwon. The synthetics were 101 to 106 c3n in plant length, medium or thick in thickness of stem, dark peen in leaf color, broad and long in flag leaf, strong in lodging resistance, and excellent in regrowth. Winter survivals of the synthetics were no different from that of Barmultra or Hwasan 101 in Suwon, but better than that of Barmultra or Hwasan 101 in Yonchun where was -10 to -12$^{\circ}C$ of minimum average air temperature in January or February. Dry matter(DM) yields of the synthetics were similar to DM 8,238kg per ha of Barmultra in Suwon, but in Yonchun, were more 7 to 13% than DM 7,291kg per ha of Barmultra. Forage qualities, IVDMD, ADF, NDF and TDN of the synthetics were lower than those of Hwasan 101, but higher than those of Barmultra.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.285-290
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• 1996

This experiment was conducted to investigate the variation of adhering primary and secondary rachis branches of panicle in three ecotypes at National Honam Agricultural Experiment Station in 1993. Three ecotypes. Odaebyeo and Sinunbongbyeo as early-maturing type, Cheongmyeongbyeo and Changanbyeo as medium, and Dongjinbyeo and Mangeumbyeo as late-maturing type were used. The treatment were 5 planting times from May 5 to 5 July by 15 day intervals. The number of primary rachis branch in early maturing type recorded high in between May 5 and 20 May as early transplanting. Medium and late-maturing type, however, was found to be have more primary rachis branches at the late time of June 20 transplanting than at the optimum transplanting of Honam area. The number of secondary rachis branch was high between June 5 and 20 June regardless ecotypes. The rate of secondary rachis branch per primary rachis branch was increased with later transplanting time up to June 5, but showed no differences onwards. The number of grain in primary and secondary rachis branches were low in transplanting time of May 5 regardless ecotype but high in late transplanting time by July 5. Densinty of seed sets was found to be higher in late transplanting than in early transplating;early-maturing type showed high in July 5 and 20 June in medium-late maturing type respectively.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.441-445
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• 2005

Researches on estimating national-scaled forest biomass are being carried out to quantify the carbon stock of forests with the Kyoto Protocol. In general, estimates of national-scaled forest biomass are based on forest inventory data which provides estimates of forest area, stem volume, and growth of stem by age classes. Estimates of forest biomass are, however, obtained by converting stem volumes to dry weight with stem density and thereafter to whole tree biomass with biomass expansion factors (ratios of whole tree dry weight to stem dry weight). Pinus densiflora is widely distributed and one of the most economically important timber species in Korea. The species are largely grouped into two ecotypes of Geumgang and Jungbu. Stems of Geumgang type trees are straight and high compared to those of Jungbu type trees. The objective of this study was to determine and compare stem density and biomass expansion factors fore two ecotypes of Pinus densiflora according to stand age. Stem density of both ecotypes of Pinus densora increased and biomass expansion factors of them decreased with increasing tree age. In he same age class, stem density and biomass expansion factor of Geungang type Pinus densiflora were lower than those of Jungbu type Pinus densiflora. There were statistically significant differences in stem density and biomass expansion factors between Geumgang type and Jungbu type Pinus densiflora in 0-20-year-old stands and 40-60-year-old stands. Our results suggested that the reliability of the national forest biomass inventory could be improved by applying the ecotype- and age-dependent stem density and biomass expansion factors.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.67-75
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• 1987

The major objectives of this study were to find out the growth and yield of two ecotypes of Korean garlic in main garlic producing districts in Korea. The data were collected by the field survey which had been conducted at 270 township in 58 major garlic production countries throughout the country on 10th, 20th, and 30th day of every month from 1982 to 1984. The results of this study were as follow: 1) Sowing period of garlic of southern and northern ecotype were around September 20 and October 20, respectively. 2) Average number of plants per $3.3m^2$ of the southern and northern ecotype were 123 and 100, respectively. 3) Leaf emergence time of southern ecotype was before the beginning of winter (November) and that of northern ecotype was from early February till April. 4) Stepwise multiple regression analysis showed that the plant heights measured on November 30 for southern ecotype and on June 30 for northern ecotype most adequately predicted the yield of garlic. The relationship between yield and plant height were as follows: Southern ecotype; Y=571.56+5.34X Northern ecotype; Y=251.81+5.45X where Y is yield expressed in Kg/l0a and X is height in cm at the respective date. 5) The number of leaves increased until harvest in both ecotypes. At harvest, the number of leaves in southern and northern ecotype were 10 and 8, respectively. Number of leaves counted on January 20 for southern ecotype and on June 20 for northern ecotype correlated best with the yield of the ecotypes. 6) The highest senescent portion of southern ecotype and northern ecotype were seen on January 30 and May 30, respectively. Stepwise multiple regression analysis showed that the senescent portion of southern ecotype counted on January 30 and that of northern ecotype on June 20 mostly affected the yield. 7) Average yield of southern and northern ecotype at the main garlic producing districts were 771 and 652Kg/10a, respectively.