• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.129-134
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• 2002

194 plantlets regenerated from leaf explants of boxthorn 'Cheonyang' were cultivated to investigate their morphological characteristics in the field for 2 years. Based on the morphology of leaves, 66.1% of them had elliptical type leaf, the same as that of mother plants, while 22.2% in oval type, 7.2% in obovate type, 2.6% in long-obvate type and 2.1% in lanceolate type. They were classified to 4 groups; group A was selected with both high fruit size and fruit yield, group B with only high fruit size, group C with larger or thicken leaf, and group D with multiple brenches. In comparision of production efficiency between the selected groups and mother plants, group A (99741, 99781, 99854, 99870 and 99886) were longer (2.1 to 2.7 mm) in length of fruits and higher in fruit production (15 to 30%) as compared to mother plants. Croup D (99797 and 99892) was higher in leaf production (7.2%) as compared to boxthorn 'CL1-48', which is the highest in leaf production among boxthorn veriaties.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.173-180
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• 2003

To clarify whether the closely related species living in the same area is a population or populations ecologically, leaf morphology, specific leaf area, and fruit and seed production were studied in the natural group of sect. Pes-gallinaceua of Corydalis of Namhansansung area from 1999 to 2000. There were 352 plants in one square meter and total eight species or varieties were identified. Of the 352 plants, the number of C. turtschaninovii was the most with 103(29.3%), and that of C. ambigua was the next with 78(22.2%), and that of C. turtschaninovii var. fumariaefolia was the smallest with 9(2.6%). In the 28 plants having spotted leaves, central leaflet did not parted or again parted. The extent of partition with the plant was various from non-parted type to perfectly two-parted type (three leaflet). Between two extreme types, there were diverse types so that this character formed a gradient. The rate of length/breadth was in the range of 0.79~2.17. This character was related to the extent of leaflet partition but did not well expressed the distinguishing trait along a species. The number and the type of serration were diverse and there was no sharp borderline among the species or varieties. Ecological properties, specific leaf area, the number of fruit per plant, and the number of seed per fruit, varied with a wide range in a species or variety but differences between species or variety were not significant. Therefore, the Corydalis group studied was regarded as a population on the three criteria: (1) possibility of interbreeding, (2) continuity of leaf morphology, (3) irrelevance between character and species, (4) similarity of several ecological properties.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.235-244
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• 2023

Acidovorax citrulli (Ac) is a phytopathogenic bacterium that causes bacterial fruit blotch (BFB) in cucurbit crops, including watermelon. However, there are no effective methods to control this disease. YggS family pyridoxal phosphate-dependent enzyme acts as a coenzyme in all transamination reactions, but its function in Ac is poorly understood. Therefore, this study uses proteomic and phenotypic analyses to characterize the functions. The Ac strain lacking the YggS family pyridoxal phosphate-dependent enzyme, AcΔyppAc(EV), virulence was wholly eradicated in geminated seed inoculation and leaf infiltration. AcΔyppAc(EV) propagation was inhibited when exposed to L-homoserine but not pyridoxine. Wild-type and mutant growth were comparable in the liquid media but not in the solid media in the minimal condition. The comparative proteomic analysis revealed that YppAc is primarily involved in cell motility and wall/membrane/envelop biogenesis. In addition, AcΔyppAc(EV) reduced biofilm formation and twitching halo production, indicating that YppAc is involved in various cellular mechanisms and possesses pleiotropic effects. Therefore, this identified protein is a potential target for developing an efficient anti-virulence reagent to control BFB.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.435-444
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• 2020

Background: As the Positive List System (PLS) is implemented in broad application to agricultural products, attention to the correct use of pesticides is also needed in the production of mulberry leaves and fruit. In this regard, three types of pesticides against mulberry popcorn disease were applied 2 - 3 times both in the field and greenhouses to prepare safety standards. Residual pesticide analysis was conducted on mulberry fruits and leaves. Methods and results: Three pesticieds, thiophanate-methyl, thiophanate-methyl·triflumizole and fluopyram registered as PLS pesticides for mulberry popcorn disease, were sprayed in the Wanju and in Buan regions, after which residual pesticide analysis was conducted using high-performance liquid chromatography (HPLC). As three pesticieds were either undetected or below the permissible level in mulberry fruit, demonstrating that they were suitable for safe spraying. However, 5.6 mg/kg of thiophanate-methyl was detected in the greenhouse after three application, which was slightly above maximum residue limit (MRL). Furthermore the level of thiophanate-methyl·triflumizole was higher than 0.2 mg/kg ("Gwasang No. 2" variety, spraying twice) or similar to 0.09 mg/kg ("Daesim" variety, spraying thrice) the permissible level (0.1T mg/kg) as the thiophanate-methyl was detected in mulberry leaves in the greenhouse. Conclusions: The spraying frequency for controlling mulberry popcorn disease in greenhouses should be limited to two times or less, especially when mulberry leaves are treated with thiophanate-methyl·triflumizole careful consideration is required if the leaves are to be used as food materials.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.20-27
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• 1994

This study was conducted to improve marketing value and productivity of cucumber which was cultivated with primary scaffold stem type (Mannungcheongjang) and lateral stem type (Sayeup). The results are summarized as follows ; 1. Investigation of fruit setting characteristics to improve cucumber training type was resulted that the fruit-thinning was effective 3 nodes in Mannung- cheongjang and 4 nodes in Sayeup, because of defected yield potential and marketing value. 2. In the matter of early growing stage after training and cucumber quality at different treatment, cucumber weight at flowering curved cucumber and growth analysis of Mannungcheongjang were good in order of horizontal>vertical>slant training. And those of Sayeup were good in order of horizontal >slant> vertical training. 3. Aspect of light reception of cucumber plant in the level of plant height and accumulated leaf area index, vertical and horizontal training are better than slant in Mannungcheongjang, and there is order of horizontal >vertical >slant training in Sayeup. 4. Horizontal training in Mannungcheongjang was superior to any other case In view of cucumber number, productivity, and marketing rate. Therefore, this training was suggest ed of best method in cucumber cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.355-367
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• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.