• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.47-53
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• 1977

Bacterial diseases of soybean has been recognized as a limiting factor of soybean production in Korea as it was estimated to cause around 10 percent of yield losses annually. The purpose of the study is to obtain information on the diseases through proving the kinds of pathogens and epidemiology, The wire brush method and multineedle appeared to be the best way of inoculation under all circumstances. Wire brush method, especially, was effective in shortening the incubation period and manifesting the lesion development by introducing more inoculum per unit of area. In case of spray inoculation it was necessary to apply a small amount(1 : 1,000) of wetting agent, twin-20, otherwise it was unabled to produce the diseases under field conditions. Two kinds of bacterial diseases caused by Pseudomonas glycinea and Xanthomonas phaseoli var. sljense were found from surveyed areas in Kore. Wild fire disease on soybean caused by Pseudomonas tabaci had not detectable during the experiment although there were several reports on the disease from other countries. when the pathogens were introduced into sterile soil, bacterial leaf blight pathogen could exsisted until 30 days while bacterial pustule pathogen survived only 4 days under the natural conditions of later June. Both bacteria, however, could produce the disease after more than 10 months period of storage in refrigerator when they were exsisted in infected plant tissues. In warehouse, non-temperature controlled, the bacteria lose their infectability within 6 months period from October to April even though they exsisted in infected tissues. Surface infested seeds with the pathogens could not produced the diseases on seedling stages of soybean plants when the seeds were planted in sterile soil after inoculation by dipping the seeds into bacterial suspensions, although germination was depressed by the pathogens when the seeds were planted on agar media.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.233-238
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• 2003

The effect of phosphate solubilizing microbes (PSM) on plant P uptake and growth in rock phosphate applied soil was tested under a greenhouse condition. Tobacco plants were grown in nonsterilized soil inoculated with Penicillium oxalicum CBPS-3F-Tsa with or without rock phosphate application as P fertilizer. Phosphorus concentration in tobacco plants was increased by the application of rock phosphate, while inoculation of soil with fungi further significantly increased P concentration in tobacco plants compared with the noninoculated treatments. Phosphorus uptake by tobacco plants was also increased by the application of rock phosphate and PSM inoculation, and the significant comparison has been made with single rock phosphate treatment. Growth of tobacco plant was also significantly increased in the treatments receiving rock phosphate, while the combined application of rock phosphate and PSM further increased plant growth. It was concluded that the positive effect of PSM inoculation on plant growth was closely related in plant P content and uptake. These results suggest that Penicillium oxalicum CBPS-3F-Tsa could solubilize insoluble soil phosphates and rock phosphate which can promote growth and P uptake of tobacco plants.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.135-149
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• 2017

In order to obtain promising rice growth-promoting microbial strains that can be used as substitutes for chemical fertilizers, 172 bacterial strains were isolated from rice roots grown in Korean and Russian soils. Out of them, the strains KR076, KR083, KR181 and RRj228 showed plant growth-promoting activities on maize seedlings. Bacillus megaterium KR076 and Bacillus sp. KR083 showed both nitrogen-fixing and plant growth-promoting activities, while Rhizobium sp. KR181 and Pseudomonas sp. RRj228 appeared to support only plant growth-promotion, but not $N_2$ fixation. Especially, RRj228 showed high growth promoting activity at low concentrations. Inoculation studies with KR083 and RRj228 revealed a high affinity to the Japonica rice variety such as Junambyeo than the Korean Tongil type variety such as Arumbyeo. Both KR083 and RRj228 strains showed rhizoplane and/or endophytic colonization in Japonica and Tongil types rice when soaked with the bacterial suspension of $1.1{\times}10^5cfu\;ml^{-1}$ for six and twelve hours. However, the total bacterial cell numbers were higher in the roots of Japonica variety than in the Tongil type. In inoculation trials with Daesanbyeo rice variety, the seedlings inoculated with KR181 and RRj228 at the rate of $2.0{\times}10^6cfu\;ml^{-1}$ showed yield increment of 35% and 33% (p < 0.01), respectively, so that they contributed to the replacement of chemical fertilizer at half doses of N, $P_2O_5$, and $K_2O$ in pots. In Junambyeo rice seedlings, the strain RRj228, when inoculated with a cell suspension of $1.8{\times}10^6cfu\;ml^{-1}$, promoted 3.4% higher yield at 70% dose than at a full dose level of N $110kg\;ha^{-1}$ in field. These results suggest that the rhizobacteria KR181 and RRj228 are prospective strains for enhancing rice performance.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1213-1222
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• 2009

The search for diverse plant growth-promoting (PGP) diazotrophic bacteria is gaining momentum as efforts are made to exploit them as biofertilizers for various economically important crops. In the present study, 17 diazotrophic strains belonging to eight different genera isolated from rice paddy fields were screened for multiple PGP traits and evaluated for their inoculation effects on canola and rice plants. All of the strains tested positive for 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity and production of indole 3-acetic acid (IAA) and ammonia ($NH_3$). Additionally, four of the strains were able to solubilize phosphorus (P), five tested positive for zinc (Zn) solubilization and sulfur (S) oxidation, and eight strains produced siderophores. Based on the presence of multiple PGP traits, 10 strains were selected for inoculation studies. Treatment with Herbaspirillum sp. RFNB26 resulted in maximum root length (54.3%), seedling vigor, and dry biomass in canola, whereas Paenibacillus sp. RFNB4 exhibited the lowest activity under gnotobiotic conditions. However, under pot culture conditions, Paenibacillus sp. RFNB4 significantly increased plant height and dry biomass production by 42.3% and 29.5%, respectively. Canola plants and rhizosphere soils inoculated with Bacillus sp. RFNB6 exhibited significantly higher nitrogenase activity. In greenhouse experiments, Serratia sp. RFNB18 increased rice plant height by 35.1%, Xanthomonas sp. RFNB24 enhanced biomass production by 84.6%, and rice rhizosphere soils inoculated with Herbaspirillum sp. RFNB26 exhibited the highest nitrogenase activity. Our findings indicate that most of the selected strains possess multiple PGP properties that significantly improve the growth parameters of the two plants when tested under controlled conditions.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.51-57
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• 1970

On the basis of the specific interrelationship between the species or variety of leguminous crops and the species or strain of nodule bacteria, Rhizobia, the rhizobial species and strain must be effectively chosen for the successful inoculation. The present paper describes on some results of the isolation and taxonomic study on the native rhizobial strains isolated from the nodules of five species of leguminous crops such as numerous varieties of soy bean, lespedeza, birdfoot trefoil, ladino and red clovers. The isolated strains of soy bean nodule bacterium, Rhizobium japonicum were grouped through the inoculation test on variety Changdanbaikmock into the effective, noneffective and toxic strain for the nodule formation. In the study of the effect of some inorganic and organic nitrogenous compounds on the growth of Rhizobium japonicum strain Ac 20, a promotive response was showed by asparagine, and glutamine, but hydroxylamine, nitrite, hydrazine and azide was inhibitory at the concentration of $10^{-2}M/l$ in mannitol-yeast extract basal medium. In the physiological characteristics each strain showed somewhat different activities of the indole-3-actic acid formation and hydrogenase and discussed with these characters in relation to nodule forming ability.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.802-809
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• 2010

Phytophthora blight of pepper is the most economically important disease in the world cultivation regions. We investigated the phytophthora blight resistance of 300 accessions of Korean landrace of hot pepper germplasms collected from 83 local regions. The disease incidence rate was checked from 7 days to 28 days at an interval of 7 days after inoculation under greenhouse conditions. Among 300 accessions, the disease incidence rate of phytophthora blight of 67 accessions of pepper germplasm was more than 60.1%, while no disease was observed in 37 accessions at 7 days after inoculation. At 28 days after inoculation, five and eleven accessions of pepper germplasm were resistance and moderate resistance to $P.$ $capsici$, respectively. Two hundred forty four susceptible accessions (81.3%) of pepper were scored as having more than 60.1% of disease incidence of phytophthora blight. This result suggests that five candidate pepper germplasm might be used as breeding resources for the phytophthora blight resistance breeding program. Also, further genetic studies should be carried out to verify this result, with the overall focus of providing information on important characteristics of pepper germplasm.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.74-81
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• 1984

The experiments were conducted to study the distribution of wilt of strawberry caused by Fusarium in Korea, the characters of the causal fnngus and its control. The results obtained are summarized as follows. 1. Wilt of strawberry has been found in Gimhae and Samrangjin, Gyeongnam province a few years ago. This disease has been spreading year after year, and observed on farms in most of the strawberry-growing areas in Korea. 2. The fungus was isolated frequently from the crowns and petioles of diseased straw berry plants, and the fungus belonging to Fusariun oxysporum in terms of the morphological characteristics of macroconidia, microconidia, chlamydospore and conidiophore on V-8 Agar. 3. The macroconidia formation of the fungus varied remarkably with the Isolates and kinds of medium tested. However. all isolates abundantly produced macroconidia on V-8 Agar. 4. The cross-inoculation tests with several forma specialis of F. oxysporum to cucumber, tomato, watermelon, luffa, cabbage, melon and strawberry were carried out. The isolates from strawberry viz. Kodama's F. oxysporum f. sp. fragariae and S-1 of the authors were pathogenic to only strawberry. The fungus was also similar in morphology and symptoms to Kodama's and Winks' isolate of F. oxysporum f. sp. fragariae. Therefore, the fungus is identified as Fusarium oxysporum Schl. f. sp. fragariae Winks & Williams. 5. The most effective fungicides were Benomyl and Homai for inhibiting sporulation and mycelial growth of the fungus. 6 The cultivar Kurumae 35, Himiko, Senga gigana and Daehak I were resistant, whereas Hokowase, Instiate Z4, Juspa, Puget beauty and Marshall were susceptible to the fungus with artificial inoculation.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.280-286
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• 1999

This studies were conducted to evaluate efficiency of microbial inoculator for active composting of food wastes. The Microbial inoculators used in this studies were purchased from different comparise to evaluate their effectiveness for composting of food waste in Korea. The number of bacteria growing at $30^{\circ}C$ in commercial inoculator collected were below $91.0{\times}10^8\;CFU/g$ which were counted from well cured compost made by animal manure. The number of bacteria in commercial microbial inoculator, such as FL, VP, B9, CM and GE were higher than that of composted at $50^{\circ}C$ or $60^{\circ}C$ of incubation temperature. Fungi were counted in GR, VP and B9 as over $10^3CFU/g$ at $30^{\circ}C$ of incubation temperature, while fungi of all the commercial inoculator collected could not grown at $50^{\circ}C$ and $60^{\circ}C$. Actinomycetes in most of the these had higher number($10^5CFU/g$) than that of compost : however, it was not detected at $60^{\circ}C$ incubation temperature from all the samples collected. The amount of carbon dioxid production was order to VP>HU>B9>GE>CM>Control>Compost in the lab scale composting test with or without inoculation of commercial inoculators, however, but the difference in carbon dioxide production was similar among each treatments. The effect of inoculation on composting parmeter such as pH changes, temperature increasing and change of chemicals properties were a little among each treatments, with or without inoculation of commercial inoculator in active composting of food waste. Using commercial inoculator did not show any statistical difference in food waste composting process under various condition such as pH changes, temperature changes, etc.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.99-107
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• 1992

Effects of the indigenous Vesicular-arbuscular mycurrhizal fungi(VAMF) on early growth response of greenhouse grown crops were experimented. This study was done to evaluate the benefit of indigenous VAMF inoculation on the early growth and the subsequent growth after transplanting of some crops such as cucumber, tomato, hot pepper, eggplant, and melon. Leaf area, shoot dry weight, and plant length of mycorrhizal greenhouse crops showed the tendency of significant or no significant increase over control plants receiving no inoculation. The levels of VA mycorrhizal colonization were increased with plant growth, and infection rates of horticultural crop except hot pepper around one week after transplanting were decreased, while that of 8 weeks after emergence of mycorrhizal seedlings were increased again and infected by around 50% at harvesting time. In spore densities in the rhizosphere soil of craps experimented, the number of spore ranged from $72.7{\pm}26.3$ to $100{\pm}10.3g^1$ on dried soil basis and high density showed in both cucumber and tomato. Total nitrogen contents in shoots were lower in the mycorrhizal plants than non-mycorrhizal one, whereas P uptake in mycorrhizal hot pepper and tomato were highly ramarkable. The K contents in the shoots of mycorrhizal cucumber and eggplent were highly enhanced. Inoculation of the indigenous VAMF enhanced shoot Ca and Mg in both tomoto and melon. The contents of Fe, Zn, Mn and Cu in shoots of mycorrhizal crops were higher than non-mycorrhizal plants and vice versa in case of eggplent. Inoculation of the indigenous VAMF to horticultural crops were effective for alleviation of transplanting shock, and pretransplanting infection improved subsequent growth by reducing the time required for establishment of a functional mycorrhizal symbiosis following transplanting.

• Journal of Sericultural and Entomological Science
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• v.8
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• pp.41-50
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• 1968

In order to achieve efficiency of laying eggs of silkworms, it is very important to eliminate noncocooning silkworms. This study is written on the basis of observation and analysis of mechanism of silkworms physiologically and anatomically. It is hoped that given herein will contribute to the effecting elimination work. Outline of the study summarize as follows: 1. It is observed through microscope that the silkworms which are seen normal state in the silk gland but no ability of cocoon making have polyhedrosis in the nerve, trachea and muscle near the tissue of the spinneret. 2. Relatively high proportion of non-cocooning silkworms are caused by the grasserie of the silkworms. 3. As a result of inoculation with purulent discharges against silkworms from first fooding through 8th day of 5th instar, number of cocooning silkworms were increased when inoculation are applied at laterer day of the instar. In the case of non-cocooning silkworms, meanwhile, resulted not big varriation when it is apllied in the early and middle of the period, but number of non-cocooning silkworm was reduced when the inoculation are given at laterer of the instar. Number of death during rearing and mounting are increased when earliest application of inoculation are carried out. 4. Symptom of grasserie was appeared more or less three days after application of the inoculation. Some silkworms which were inoculated just before mounting has ability of cocooning making even taken grasserie, in this case the silkworm can make thin cocoon. since the silkworm fall sick during cocoon making and unable of spinning soon. when the worm was affected by grasserie slightly, it was observed that the silkworm can spinning. It is supposed to be the light paralysis of spinneret is not very much influenced to spinning. 5. As a result of observation of original stock and hybrid including other 44 kinds of silkworm, many non-cocooning silkworms were found in the original stock especially originated from japanese than in hybrid. 6. A number of undulations are found in the middle division of the silk gland of non-cocooning silkworms. 7. According to the observation of the sizes of the body and digestive organs, normal natured silkworms and non-cocooning silkworms are more or less same in length, but the width, circumference of bodies and digestive organs were more larger in the later. If silkworm which was in the period of active eating of 5th instar was given shock of dropping to the floor, the silkworm receives little more shock when hit to side of the body than to head, and concrete floor than ondol and wooden floor.