• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.66-70
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• 2005

The experiment was carried out to investigate the effects of gamma radiation on the early growth performance and physiological traits of BT2 clone tea, the most promising cultivar released by Bangladesh Tea Research Institute. The fresh shoot cuttings were irradiated with seven different levels of gamma radiation such as 0, 10, 20, 30, 40, 50 and 60 Gy from Cobalt 60Co source (Dept. of PlantBreeding, Bangladesh Institute of Nuclear Agriculture). Thereafter, the irradiated shoot cuttings were planted in polythene bags and kept under natural conditions. It was observed that callusing was initiated from 8th weeks after placement of tea shoot cuttings in the polythene bags and completed by 12th weeks. The morphological growth of tea shoot cuttings were recorded under varying levels of gamma radiation and growth stages. It was observed that the number of leaves, number of primary branches, base diameter, root length and total leaf area per plant significantly increased with the progress of time and increasing levels of gamma radiation, however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic makeup. After 56 weeks of planting, the plant height, the number of leaves and primary branches per plant, base diameter, root length and total leaf area per plant recorded were 65.70 cm, 30.67, 7.33, 1.48 cm, 23.50 cm, and 1250.67 cm2 per plant respectively under the radiation level 60 Gy, whereas the corresponding figures of the above parameters at the control treatment were 76.21 cm, 18.33, 3.67, 0.92 cm, 17.75 cm and 778.33 cm2 per plant, respectively. A significant relationship was observed among the physiological growth parameters with the increasing levels of gamma radiation. The total dry matter gain, leaf area index, absolute growth rate and relative growth rate were significantly influenced with the rising levels of gamma radiation (up to 60 Gy), whereas the net assimilation rate of individual tea plant non-significantly responded as compared to those of control treatment. Finally after 56 weeks of planting, the maximum total dry weight gain, leaf area index, absolute growth rate, relative growth rate and net assimilation rate recorded under 60 Gay radiation level were 40.25 g/plant/week, 4.25, 1.18 g/week, 0.0621g/g/week and 17.07 g/m2/week respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.85-92
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• 2008

An RIL population from a Shinpaldalkong2/GC83006 cross was employed to identify quantitative trait loci (QTL) associated with agronomic traits in soybean. The genetic map consisted of 127 loci which covered about 3,000cM and were assigned into 20 linkage groups. Phenotypic data were collected for the following traits; plant height, leaf area, flowering time, pubescence color, seed coat color and hilum color in 2005. Seed weight was evaluated using seeds collected in 2003 to 2005 at Suwon and in 2005 at Pyeongchang and Miryang sites. Three QTLs were associated with 100-seed weight in the combined analysis across three years. Among the three QTLs related to seed weight, all GC83006 alleles on LG O ($R^2\;=\;12.5$), LG A1 ($R^2\;=\;10.1$) and LG C2 ($R^2\;=\;11.5$) increased the seed weight. A QTL conditioning plant height was linked to markers including Satt134 (LG C2, $R^2\;=\;25.4$), and the GC83006 allele increased plant height at this QTL locus. For two QTLs related to leaf area, 1aM on LG M ($R^2\;=\;10.0$) and laL on LG L ($R^2\;=\;8.6$), the Shinpaldalkong2 alleles had positive effect to increase the leaf area. Satt134 on LG C2 ($R^2\;=\;41.0$) was associated with QTL for days to flowering. Satt134 (LG C2) showed a linkage to a gene for pubescence color. Satt363 (LG C2) and Satt354 (LG I) were linked to the hilum color gene, and Sat077 (LG D1a) was linked to the seed coat color. The QTL conditioning plant height was in the similar genomic location as the QTLs for days to flowering in this population, indicating pleiotropic effect of one gene or the tight linkage of several genes. These linked markers would be useful in marker assisted selection for these traits in a soybean breeding program.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.311-319
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• 2011

Overusing chemical fertilizers involves potassium accumulation in the soil, which can become a toxicity problem in agriculture. This study was conducted to investigate the effect of potassium (K) treatment on growth, physiological characteristics, and morphological changes using Chinese cabbage (Brassica rapa L. ssp. campestris). With high (600 mM) K treatment, the plant growth traits of leaf length, leaf area, and fresh and dry weight of shoots and roots decreased, whereas chlorophyll content increased. As the concentration of K increasing, total N, P, and K increased in leaves, but concentrations of Ca, Mg, and Na decreased. However, Mn, Fe and Zn contents were highest in 100 mM K treatment. Chlorophyll a, b, and carotenoids increased with increasing K concentration. Maximum photochemical efficiency ($F_v/F_m$) was not significant in the all treatments, whereas $CO_2$ assimilation decreased with increasing K level due to stomatal degradation. Total free amino acids increased with the 10 and 100 mM K but decreased at 600 mM K treatments. Therefore, the growth and physiological characteristics of Chinese cabbage ascertained that tolerance up to 100 mM K when grown with nutrient solution in pot culture.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.393-405
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• 2021

With increasing anthropogenic emission sources, air pollutants are emerging as a severe environmental problem worldwide. Accordingly, the importance of landscape trees is emerging as a potential solution to reduce air pollutants, especially in urban areas. This study quantified and compared NO₂ and SO₂ reduction abilities of ten major landscape tree species and analyzed the relationship between reduction ability and physiological and morphological characteristics. The results showed NO₂ reduction per leaf area was greatest in Cornus officinalis (19.81 ± 3.84 ng cm^-2 hr^-1) and lowest in Pinus strobus (1.51 ± 0.81 ng cm^-2 hr^-1). In addition, NO₂ reduction by broadleaf species (14.72 ± 1.32 ng cm^-2 hr^-1) was 3.1-times greater than needleleaf species (4.68 ± 1.26 ng cm^-2hr^-1; P < 0.001). Further, SO₂ reduction per leaf area was greatest in Zelkova serrata (70.04 ± 7.74 ng cm^-2 hr^-1) and lowest in Pinus strobus (4.79 ± 1.02 ng cm^-2 hr^-1). Similarly, SO₂ reduction by broadleaf species (44.21 ± 5.01 ng cm^-2 hr^-1) was 3.9-times greater than needleleaf species (11.47 ± 3.03 ng cm^-2 hr^-1; P < 0.001). Correlation analysis revealed differences in NO₂ reduction was best explained by chlorophyll b content (R² = 0.671, P = 0.003) and SO₂ reduction was best described by SLA and length of margin per leaf area (R² = 0.456, P = 0.032 and R² = 0.437, P = 0.001, R² = 0.872, P < 0.001, respectively). In summary, the ability of trees to reduce air pollutants was related to photosynthesis, evapotranspiration, stomatal conductance, and leaf thickness. These findings highlight effective reduction of air pollutants by landscaping trees requires comprehensively analyzing physiological and morphological species characteristics.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.555-563
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• 2016

The morphological characteristics and genetic relationships among 32 germplasms of Zanthoxylum schinifolium and Zanthoxylum piperitum collected from two farms in Korea were investigated. The traits with the most variability were seed color, leaf size, and spine size. The intraspecific polymorphism of Z. schinifolium and Z. piperitum was 96.5% and 60.3%, respectively. The genetic diversity and Shannon’s information index values ranged from 0.11 to 0.33 and 0.19 to 0.50, with average values of 0.26 and 0.42, respectively. Two ISSR primers (UBC861 and UBC862) were able to distinguish the different species. The genetic similarity matrix (GSM) revealed variability among the accessions ranging from 0.116 to 0.816. The intraspecific GSM for Z. schinifolium and Z. piperitum was 0.177-0.780 and 0.250-0.816, respectively. The GSM findings indicate that Z. schinifolium and Z. piperitum accessions have high genetic diversity and possess germplasms qualifying as good genetic resources for cross breeding. The clustering analysis separated Z. schinifolium and Z. piperitum into independent groups, and all accessions could be classified into three categories. Z. Schinifolium var. nermis belonged to independent groups. Comparison of the clusters based on morphological analysis with those based on ISSR data resulted in an unclear pattern of division among the accessions. The study findings indicate that Z. schinifolium and Z. piperitum accessions have genetic diversity, and ISSR markers were useful for identifying Z. schinifolium and Z. piperitum.

• Mycobiology
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• v.48 no.1
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• pp.37-43
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• 2020

A serious leaf disease caused by Colletotrichum dematium was found during the cultivation of Sarcandra glabra in Jingxi, Rong'an, and Donglan Counties in Guangxi Province, which inflicted huge losses to plant productivity. Biological control gradually became an effective control method for plant pathogens. Many studies showed that the application of actinomycetes in biological control has been effective. Therefore, it may be of great significance to study the application of actinomycetes on controlling the diseases caused by S. glabra. Strains of antifungal actinomycetes capable of inhibiting C. dematium were identified, isolated and screened from healthy plants tissues and the rhizospheres in soils containing S. glabra. In this study, 15 actinomycetes strains were isolated and among these, strains JT-2F, DT-3F, and JJ-3F, appeared to show antagonistic effects against anthracnose of S. glabra. The strains JT-2F and DT-3F were isolated from soil, while JJ-3F was isolated from plant stems. The antagonism rate of strain JT-2F was 86.75%, which was the highest value among the three strains. Additionally, the JT-2F strain also had the strongest antagonistic activity when the antagonistic activities were tested against seven plant pathogens. Strain JT-2F is able to produce proteases and cellulase to degrade the protein and cellulose components of cell walls of C. dematium, respectively. This results in mycelia damage which leads to inhibition of the growth of C. dematium. Strain JT-2F was identified as Streptomyces tsukiyonensis based on morphological traits and 16S rDNA sequence analysis.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.92-100
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• 2009

To investigate the mutagenecity of sodium azide (SA) and to select mutants having various agronomic characteristics in rice (Oryza sativa L. ssp. japonica), dry seeds of rice variety 'Suweon 472' were treated with 0, 0.5, 1.0, 2.0, and 4.0 mM SA solutions prepared in 0.1 M phosphate buffer (pH 3.0). Germination rate, seedling height and sterility were investigated in $M_1$ generation and chlorophyll mutations were observed in $M_3$ generation. Germination rate and seedling height decreased as the increase of SA concentration in $M_1$ generation, the maximum seed sterility (40.8%) was found at 4.0 mM SA concentration. Chlorophyll mutants were occurred in $M_3$ generation and the frequency calculated on a line basis was 13.5% at the same treatment. Many kinds of mutations for morphological and agronomic characters were observed and mutations with short culm and glabrous leaf were frequently found in $M_3$ generation. Interestingly, five mutant lines resistant to blast or bacterial blight (BB) were selected and evaluated with several isolates in $M_3$ generation although Suweon 472 has been known to be susceptible to blast and BB. These mutants showed all resistance to seven isolates of blast and a total of 76 lines among 2,567 lines evaluated showed resistant to race K1 of bacterial blight. Two mutant lines (440172 and 41272) showed different reaction to BB isolates from the other resistant mutants. A few kinds of endosperm mutants were also identified and most of them were waxy mutants.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.11-31
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• 1980

The morphological, anatomical and physiological traits were eximined for Populus alba ${\times}$ glandulosa which is an important planting species in Korea. The results obtained are as follows: 1. External characters in the leaf shape and chaff shape in the catkin were inherited as incomplete dominance but nectar gland was inherited as dominance. 2. Among the 15 selected clones, 9 clones were male, 2 clones female and 2 clones monoecious. 3. There were well-developed cork layers and bast fiber bundles in the bark. 4. Primordial leaves composed of 3 layers of cells and those undifferentiated into palisade and spongy parenchymas differed in its origin. 5. Leaf scare consisted of two kinds of tissues; one is connected to vascular bundle and the other not to vascular bundle. Tissues which had been connected to vascular bundle were isolated with only 2 or 3 layers of cork cells from the outside. 6. There was complicated arrangement in the vascular bundle of petioles. 7. Growth of the hybrid was sensitively influenced by external temperature, day-length and amount of light. In particular, it was apparent in height growth. 8. Flatness, loam soils and a $60{\times}60cm$ spacing might be best factors for the growth of P. alba ${\times}$ glandulosa. 9. The rooting of 15 clones was dependant upon external factors. 10. The growth of P. alba ${\times}$ glandulosa was best at around 80% of soil moisture content on the basis of plot water capacity. 11. Temperature difference between inside and outside stems below 100cm during the winter was the greatest at the south among seasons and among directions. 12. The sap movement was markedly influenced by air temperature, relative humidity in forest stand and moisture content in stem. 13. Total sugars in the cortex changed with season but did not differ in the dircetion of the stem. 14. Isoperoxidase variations in the leaf were different among 15 clones. Thus, it may be useful as a criterium for clonal identification. 15. The rate of soil moisture content decreased at a rapid slope was faster than that at a slow slope. Poor growth of P. alba ${\times}$ glandulosa at the slope was probably due to depletion of soil moisture.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.22-34
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• 2024

Recently, in several regions of Korea, we discovered the occurrence of Sagina micropetala Rauschert and S. procumbens L. All the plants of the genus Sagina growing in Korea are 5-merous and belong to the sect. Spergella. However, the two taxa we discovered belong to the sect. Saginella and are 4-merous. In addition, morphological characteristics such as sepals during the fruiting season and seeds were significantly different from those of species of the genus Sagina that occur in Korea. To clearly identify these species, we compared and observed their primary morphological characteristics using illustrated books and literature. Morphologically, S. micropetala exhibits the following traits: pubescence along the leaf margin, horizontally spreading sepals with red margins, and convex protrusions on the seed surface. In contrast, S. procumbens can be distinguished by its pedicels, which are curved during the flowering season and erect during the fruiting season. This plant also has broadly ovate sepals with white or yellowish-green margins, and flat seed surface protrusions. In terms of molecular analyses, 19 samples of Sagina were divided into two clades (S. micropetala and S. procumbens), confirming the taxonomic identity of the Sagina spp.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.79-88
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• 2021

This research was conducted to investigate the genetic diversity and select useful accession with agronomic characteristics of garlic (Allium sativum L.). germplasms at Garlic Research Institute in Chungbuk Agricultural Research and Extension Service. Morphological diversity and relationships among 160 germplasms collected from 26 countries were assessed by methods of clustering and principal component analysis. Among 11 types of leaves and bulbs characteristics, emergence days of leaf showed the highest variation with coefficient of variation of 84.8%, and the bulb weight and the number of scales showed higher variability with 24.3%. Correlation analysis based on 11 quantitative traits showed that bulb weight and bulb length have very high positive correlation with bulb quantity. Plant height, leaf length, and number of leaves showed positive correlation with bulb weight as collections with better performance in growth produced large bulb with higher quality. The cluster analysis based on 5 principal components generated 6 clusters with an average distance of 1.6 among clusters. Domestic genetic resources were the largest with 36 species (22.5%) in group II.