• 한국작물학회지
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• 제53권3호
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• pp.303-307
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• 2008

Cotyledon Black Decay (CBD) on soybean sprout mimics the black spot due to microbial infection. CBD, not visible or predictable at seedlot state, for some reason, shows up exclusively on cotyledon of soybean sprout during sprouting process. Such an incidence rate fluctuated from 0.8 to 19.5% over three years from 2004. We suspected some pod-infecting anthracnose fungi and/or pod-blight pathogen, or pod-sucking bean bug, one of the major pests of soybean, might have involved, of which we ruled out fungal pathogen because it was preventable through heat treatment, a proven method for seedlot disinfestation. The healthy seeds artificially fed by bean bug for one to seven days were sprouted, and 6 to 41% of the soybean sprout revealed the CBD mimic to those occurred in soybean sprout from previous commercial seedlot screening experiments. This finding is the first report to confirm that bean bug damage to pod at $R_8$ stage is directly responsible for the CBD, which did not concur with any other deleterious effects on sprouting such as reduction in hypocotyls elongation and rooting except unsightly sprout quality. However, earlier feeding either at green pod or greenish yellow pod stage ($R_6$ -early $R_7$ stage) resulted in rather severe damages, which strikingly reduced hypocotyls growth to about one forth to about two third, as well as the reduction in rates of seed germination.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.221-221
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• 2022

Chromosome breakage occurred by DNA methylation inhibitor. Zebularine is known as DNA methylation inhibitor and suitable for water solubility among different DNA methylation inhibitors as 5-Azacytidine and 5-aza-2'-deoxycytidine. We used zebularine as mutagen according to different methods by roots absorption and seed imbibition. After zebularine treatment, DNA methylation inhibitor, we observed mitotic chromosome behavior what is different according to two different treatment methods. First, seed imbibition treatment in 1,000 μM of zebularine solution for 72 hours in dark conditions. The second treatment to seedlings of Keumkang was also treated in 1,000 μM of zebularine solution for 72 hours after germination. Root and shoot showed different elongations in each treatment. Root absorption treatment(3.01±0.48, 2.00±0.26) showed the shortest elongation in root and shoot than control(8.16±0.61, 4.03±0.48) and seed imbibition treatment(4.33±0.80, 2.48±0.36). It can be explained root tip meristematic cell activity was damaged by DNA methylation inhibitor. Primary root tips were collected in DW for 24 hours at low temperature(0℃) and fixed in fixation solution for 3 days to chromosome observation in mitosis. Mitotic index, chromosome structure and chromosome aberration were observed by phase-contrast microscope. Mitotic index of the control(0.29) showed twice mitotic cells as the treated groups(imbibition 0.15, absorption 0.14). Observation of chromosomes showed some short chromosomes and loosen chromosomes affected by zebularine. It is considered because of zebularine damage DNA in mitosis. We observed "gap by chromosome breakage" in chromosomes that have loose parts between centromere and telomere. It seems demethylation of zebularine occurs chromosome breakage.

• 한국작물학회지
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• 제20권
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• pp.115-121
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• 1975

맥후작 면화재배에서 숙기를 단축하고 적채면수량을 증가시키고자 본실험을 실시하였든바 그 결과를 요약하면 다음과 같다. 1) 맥후작 면화재배에서 10월상순 Ethrel를 산포하면 적채면화율이 무처리구의 38%에 비하여 2,000ppm처리구의 그것은 93%였으며 개서는 20일이나 앞당겨 졌다. 2) 수량에서는 무처리구에 비하여 Ethrel처리구가 15%∼38%까지 증수되었다. 3) 한편 섬유장과 섬유장력에 있어서는 처리구는 무처리구와 차이 없었으나 적채면과 목채면간에는 무처리구 및 Ethrel처리구에 있어서 각각 평균 1.3mm 정도 목채면이 더 짧았다. 4) 1삭중과 종자 100립중에서도 Ethrel처리로 인한 차이는 전혀 없었으나 적채면과 목채면간에서는 목채면이 훨씬 가벼웠다. 5) Ethrel로 처리된 적채면종자는 무처리의 그것에 비하여 발아가 촉진되었다. 그러나 목채면종자의 발아율은 철된것이나 안된것이나 바슷했다. 6) 이상의 결과로서 맥후작면화재배에 있어서 만숙장섬유품종을 도입하여도 Ethrel를 적용하면 적채면수량이 더욱 증가된다고 본다.

• 대한방사선기술학회지:방사선기술과학
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• 제44권3호
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• pp.253-260
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• 2021

The purpose of this study is to measure of growth and chlorophyl in barley exposed by X-ray. Barley seed was soaked 24h duration in water, then was classified into two group; pre-seed germination group (Pre-G) or post-seed germination group (Post-G). Also, divided as control subgroup and experimental subgroup(10Gy, 20Gy, 30Gy) in each group. Experimental subgroups were exposed by X-ray using linear accelerator (Clinac IS, VERIAN, USA). Expose condition was 6 MV X-ray, SSD 100 cm, 18×10 cm, 600 MU/min. Length was measured every day for 10 days and 10th day for weight. Chlorophyl was analyzed using spectrophotometer(uv-1800, shimadzu, japan) in l0th day. Data analysis was performed using SPSS ver 22.0(Chicago, IL, USA), ANOVA test (Dunnett_T3) between control subgroup and experimental subgroup in group and Independent T-test between Pre-G and Post-G in subgroup. In Pre-G, length of barley was significantly difference between control and 30Gy in 4th day (4.3 vs. 1.5, p= 0.011). Length of 30Gy was statistical difference with control(10th day; 14.4 vs. 6.3, p < 0.01), and was not in 10Gy or 20Gy in all day. In experimental subgroup, length was shorter as increasing radiation dose. In Post-G, length of barley was not difference statistically between control and experimental subgroup in first day, but more difference between two subgroup with increasing duration after exposing. Length of experimental subgroup was shorter significantly compared with control in 10th day, and no significant difference between experimental subgroup. Density of chlorophyl was increasing with increasing radiation dose in Pre-G and Post-G. Chlorophyl density of control was lower than 30Gy; 0.26ppm in Pre-G, 0.29ppm in Post-G). Growth and chlorophyl of barley was effected by X-ray. It is expected to be used as basic data for future radiobiological research.

• 한국응용곤충학회지
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• 제26권4호
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• pp.221-228
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• 1987

도열병균(稻熱病菌)(Pyricularia oryzae)의 포자발아(胞子發芽)에 가장 적합한 온도는 $26{\sim}30^{\circ}C$였으며, 발아(發芽)에 필요한 최소한의 수분존재시간(水分存在時間)은 4시간으로 나타났고, $34^{\circ}C$에서는 발아율(發芽率)이 10% 이하로 낮게 나타났다. 포자발아(胞子發芽)에 대한 상대습도의 영향은 고온(高溫)인 $34^{\circ}C$에서만 차이가 있었고 나머지 처리에서는 유의적(有意的)인 차이가 없었다(P>0.05). 발병효율(發病效率)은 $26^{\circ}C$에서 가장 높게 나타났으며 $18^{\circ}C$와 $22^{\circ}C,\;30^{\circ}C$에서는 $26^{\circ}C$에 비해 약 20% 정도였다. 주당(株當) 1개 이상의 병반(病斑)을 형성하는데 필요한 평균수분존재시간(平均水分存在時間)은 $18^{\circ}C$에서 22시간, $22^{\circ}C$에서 16시간, $26^{\circ}C$에서 10시간, $30^{\circ}C$에서는 8시간이었으며, $34^{\circ}C$에서는 주당(株當) 1개 이상의 병반(病斑)을 형성하지 못하였다. 접종(接種)후 병반(病斑) 발현시(發現時)까지의 잠복기간(潛伏其間)은 $18^{\circ}C$에서 $7{\sim}8$일(日), $22{\sim}26^{\circ}C$에서는 약 $4{\sim}5$일(日), $30^{\circ}C$에서는 $3{\sim}4$일(日)이었다. 병반(病斑) 크기 증가율(增加率)은 온도 및 습도조건과 밀접한 관계를 보였다. 1일당(日當) 평균(平均) 병반(病斑) 크기 증분(增分)은 상대습도 90% 이상인 경우, $18^{\circ}C$와 $22^{\circ}C$에서 0.7mm, $26^{\circ}C$에서 1mm, $30^{\circ}C$에서는 0.8mm 였고, 상대습도 85% 이하에서는 $30^{\circ}C$를 제외한 온도 조건에서 90% 이상에서의 증분(增分)의 $50{\sim}60%$ 밖에 되지 않았다.

• 한국작물학회지
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• 제67권3호
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• pp.180-188
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• 2022

본 연구는 2017년에서 2018년까지 전북지역(완주)에서 하파가 가능한 귀리품종인 「다크호스」와 「하이스피드」를 대상으로 종자 부족을 대비한 단경기 종자생산의 가능여부를 판단하기 위하여 파종 시기에 따라 생육 및 종자 소질 등을 평가하여 하파 귀리의 최적 파종 시기를 구명하고자 하였다. 1. 여름철 7~8월, 4차례에 걸친 파종 시기에 따라 품종별 적산온도를 분석한 결과, 종실 생산을 위한 적산온도는 두 품종 모두 파종 후 성숙까지 약 1,600℃ 내외의 적산온도가 필요한 것으로 나타났다. 2. 2017년 시험에서는 다크호스가 7월 15일(1차) 파종이 10a 당 132 kg로 수량이 가장 적었고, 7월 30일(2차) 파종은 227 kg, 8월 15일(3차) 파종은 212 kg로 2차 파종이 가장 많았으며, 하이스피드는 1차 파종에서 역시 126 kg로 가장 적었고, 2차 파종은 211 kg, 3차 파종에서 219 kg로 가장 많았다. 3. 2018년 시험의 종실 수량성은 다크호스가 10a당 1차파종 184 kg로 가장 적었고, 2차파종은 240 kg, 3차파종은 216 kg로 2차파종이 가장 많았으나 통계적인 유의성은 없었으며, 하이스피드에서는 1차파종이 160 kg로 가장 적었고, 2차 파종은 258 kg, 3차 파종은 249 kg로 2차 파종에서 가장 높았다. 4. 2017년 여름 시기별로 파종한 식물체의 종실을 수확하여 이듬해 파종을 위한 종자 발아율을 검정한 결과 1차에서 3차 파종 시기까지 재배하여 수확한 종자는 발아율이 모두 85% 이상으로 높았으며, 특히, 2차 파종한 식물체에서 얻어진 종자의 발아율이 95% 이상으로 가장 높았다. 5. 2018년 발아율 시험의 경우 1차부터 3차까지 파종한 식물체에서 생산된 종실의 발아율이 모두 90% 이상으로 매우 높았으나, 통계적인 유의성은 없었다. 6. 이상의 결과를 토대로 종실 수확을 위한 하파 귀리의 최적 파종 시기는 7월 30일(2차)에서 8월 15일(3차) 사이 파종이 적합하며, 이 기간 내의 파종이 종실 수량을 높이는데 최적일 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.52-57
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• 2007

Growth promotion of wild plants by some plant growth-promoting rhizobacteria (PGPR) was examined in the microcosms composed of soils collected separately from a grass-covered site and a nongrass-covered site in a lakeside barren area at Lake Paro, Korea. After sowing the seeds of eight kinds of wild plants and inoculation of several strains of PGPR, the total bacterial number and microbial activity were measured during 5 months of study period, and the plant biomasses grown were compared at the end of the study. Acridine orange direct counts in the inoculated microcosms, $1.3-9.8{\times}10^9\;cells{\cdot}g\;soil^{-1}$ in the soil from the grass-covered area and $0.9-7.2{\times}10^9\;cells{\cdot}g\;soil^{-1}$ in the soil from the nongrass-covered site, were almost twice higher than those in the uninoculated microcosms. The number of Pseudomonas sp., well-known bacteria as PGPR, and the soil dehydrogenase activity were also higher in the inoculated soils than the uninoculated soils. The first germination of sowed seeds in the inoculated microcosm was 5 days earlier than the uninoculated microcosm. Average lengths of all plants grown during the study period were 26% and 29% longer in the inoculated microcosms starting with the grass-covered soil and the nongrass-covered soil, respectively, compared with those in the uninoculated microcosms. Dry weights of whole plants grown were 67-82% higher in the inoculated microcosms than the uninoculated microcosms. Microbial population and activity and growth promoting effect by PGPR were all higher in the soils collected from the grass-covered area than in the nongrass-covered area. The growth enhancement of wild plants seemed to occur by the activities of inoculated microorganisms, and this capability of PGPR may be utilized for rapid revegetation of some barren lands.

• Plant Biotechnology Reports
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• 제2권4호
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• pp.259-265
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• 2008

Picea koraiensis, called Korean spruce, is an evergreen tree and found mostly in northeast Asia. In this study, plant regeneration via somatic embryogenesis from open-pollinated immature zygotic embryos of nine geno-types of elite trees was established. Immature zygotic embryos were cultured onto RJW medium modified from 505 medium with $21.48{\mu}M$ NAA, $2.22{\mu}M$ BA, and $2.32{\mu}M$ KT. The average frequency for all nine genotypes was 74.2%. Embryogenic calluses of the nine genotypes of elite trees were subcultured on RJW basal medium containing $8.06{\mu}M$ NAA, $1.11{\mu}M$ BA, and $1.16{\mu}M$ kinetin. The calluses of three lines, $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$, were actively proliferated but others were not. Somatic embryogenesis was induced from the embryogenic callus in genotypes of $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$ on RJW medium with ABA and $60g\;l^{-1}$ sucrose. Cotyledonary somatic embryos were subjected to a drying process. The drying of embryos by uncapping the culture bottle for 5 days on a clean bench resulted in a high frequency of germination of somatic embryos (87% in RJW medium). However, plantlet conversion from germinated embryos was greatly reduced and the optimal medium for plant conversion was 1/2 WPM or 1/2 BMI medium. In conclusion, we have, for the first time, established a plant regeneration system via somatic embryogenesis in the Korean spruce, which can be applied for rapid micropropagation of elite trees.

• 한국약용작물학회지
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• 제5권4호
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• pp.307-313
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• 1997

발아율을 증가시키기 위하여 실험실에서 수행된 초롱꽃과 약용작물의 종자처리(種子處理)가 출아율(出芽率)과 유묘생장(幼苗生長)을 촉진할 수 있는가를 검토하기 위하여 도라지, 더덕 및 만삼 종자를 파종 전 증류수에 2일간 침지하거나, $Ca(NO_3)_2$ 150 mM에 2일간 priming 또는 $GA_3$ 0.1 mM에 3일간 침지한 3개(個) 처리(處理)로 구분하여 유묘 출아율(幼苗 出芽率)과 파종 38일 후에 유묘생장(幼苗生長)을 조사하였으며 만삼의 출아율(出芽率)이 낮은 원인을 구명하기 위하여 전자현미경으로 종자의 내부구조를 관찰하였던 바 그 결과를 요약하면 다음과 같다. 1. 유묘 출아율(幼苗 出芽率)에서 도라지는 Priming과 $GA_3$ 처리, 더덕은 $GA_3$ 처리, 만삼은 priming처리에서 증류수로 침지 처리하는 것보다 높았고, 출아소요일수(出芽所要日數)도 도라지와 더덕은 대조구(對照區)에 비하여 $GA_3$처리로 단축되었다. 2. 공시종(供試種) 모두 하경축장(下經軸長)은 처리간 차이가 없었던 반면, 도라지와 더덕은 priming처리로 초장(草長)은 짧고 주당엽수(株當葉數)도 적었으나 만삼은 차이가 없었다. 3. 지상부중, 근중(地上部重, 根重) 또는 주당 건물중(株當 乾物重)은 대조구(對照區)에 비하여 $GA_3$ 처리에서 높은 반면, priming 처리에서 낮았다. 4. 만삼의 출아율저조원인(出芽率低調原因)은 무경(無經), 천(賤)의 형태적(形態的) 결함(缺陷) 등 종자구조에서 비롯되는 것으로 분석되었다.

• The Plant Pathology Journal
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• 제17권3호
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• pp.141-148
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• 2001

Postharvest decay of onion bulbs was examined by inspecting the commercial packages in the market or in storage. Bulb rot incidence was unexpectedly high, and onion bulbs with 1st quality grade were rotten most severely by 51%, followed by 32% for 2nd and 21% for 3rd grades. This indicates that larger bulbs had higher incidences of bulb rots. Major pathogens associated with basal and neck rots were Fusarium oxysporum and Aspergillus sp. or Botrytis allii, respectively, of which basal rot was most prevalent and damaging during storage. Among the epiphytic microorgani는 from onion plants, several Bacillus and Paenibacillus spp. and previously selected Pseudomonas putida and Trichoderma harzianum had inhibitory efficacy against bulb rot pathogens. Among these B. amyloliquefaciens BL-3, Paenibacillus polymyxa BL-4, and P. putida Cha 94 were highly inhibitory to conidial germination of F. oxysporum and B. allii. P. putida Cha 94, B. amyloliquefaciens BL-3, P. polymyxa BL-4, and T. harzianum TM were applied in the rhizoplane of onion at transplanting. Initially antagonist populations decreased rapidly during the first one month. However, among these antagonists, rhizoplane population densities of BL-3, Cha 94, and TM were consistently high thereafter, maintaining about 10$^4$-10$^{5}$ cells or spores per gram of onion root up to harvest time. The other bacterial antagonist BL-4 survived only for two months. TM was the most effective biocontrol agent against basal rot, with the number of rotten bulbs recorded at 4%, while that of the control was 16%. Cha 94 was effective for the first 20 days, but basal rot increased thereafter and had about the same control efficacy as that of BL-3 and BL-4. When the antagonists were applied to the topping areas of onion bulbs at harvest, TM was the most effective in protecting the stored onion bulbs from neck rotting. The second effective antagonist was BL-3. TM and BL-3 completely suppressed the neck rot in another test, suggesting that biocontrol of postharvest decay of onion using these microorganisms either at the time of transplanting or at harvesting may be promising.