• 미생물학회지
• /
• 제43권4호
• /
• pp.279-284
• /
• 2007

식물호르몬(phytohormone)을 생성하며 불용성 인산 가용화능이 있는 세균을 근권에서 분리하여 각각의 생성능을 조사하고 토마토 씨앗에 적용하여 생장촉진 가능성을 조사함으로써 분리 균주의 생물학적 비료로서의 가능성을 제시하고자 하였다. 분리 균주인 Bacillus sp. PS2와 RFO41은 첨가된 두 종류의 500 mg/L 불용성 인산을 약 80% 이상 가용화 시켰으며, 펩톤이 풍부한 생장배지에서 여러 가지 식물호르몬을 생성하였다. 이를 토대로 토마토 씨앗의 생장촉진 실험을 수행한 결과, PS2와 RFO41이 적용된 실험군의 발아한 토마토모종의 뿌리와 줄기의 길이 생장은 대조군에 비하여 각각 26.8과 34.8% 및 45.5와 36.5%가 증가하였다. 이 결과는 분리 균주인 Bacillus sp. PS2와 RFO41의 인산 가용화능과 식물호르몬의 생성능이 토마토 씨앗의 발아와 생장에 직접적인 영향을 주는 요인으로 작용한 결과라고 판단할 수 있으며, 생물학적 비료로서의 가치를 뒷받침하는 것이라고 할 수 있다.

• The Korean Journal of Ecology
• /
• 제25권1호
• /
• pp.1-7
• /
• 2002

The ecological background of a restoration project is complex and difficult to betermine without experimentation. A useful context for experiments is the well-studied process of natural succession, because the factors that drive or inhibit succession are also at work during reclamation (a form of primary succession) and restoration (which often resembles secondary succession). Using experimental studies on urban wasteland reclamation, we have tested for factors that stimulate or inhibit succession during early phases of woodland development in the Northeastern United states. The emphasis has been on mutualisms (seed dispersal, pollination, and mycorrhizae) and microsite limitations in the recruitment, growth, and reproduction of woody plants. Using plantings of seeds, seedlings, and clusters of reproductively mature plants on abandoned landfills, we have observed that (1) soil microsite deficiencies lead to very poor germination (<0.1$\%$) and seedling survival (<0.01$\%$) of most native species; (2) seed dispersal by birds is a significant and reliable source of woody plant recruitment; however (3) proximity effects are strong, with most (up to 95$\%$) of seed rain falling in the vicinity of planted clusters that are closest to putative seed sources; and (4) remnant natural woodlands are critical components of the recruitment process. To emphasize the last point, in one case, we found that the destruction of approximately 50$\%$ of nearby natural woodland vegetation led to a commensurate decline in seed rain. In another case, we found that the species richness of recruits was strictly limited by the species composition of nearby source plant communities, with no evidence of community enrichment by long distance dispersal over 5 years. We conclude from these results that the size and proximity of remnant natural populations are critical considerations when planning reclamation and restoration programs that rely on natural successional processes.

• 한국산림과학회지
• /
• 제67권1호
• /
• pp.10-16
• /
• 1984

Pt균계(菌系)를 증식배양후(增殖培養後) 인공접종(人工接種)한 상수리나무 분묘(盆苗)는 온실내(温室內)에서 자랐으며, 외생균근(外生菌根) Pt가 상수리나무 분묘(盆苗)의 생장(生長)과 발달(發達)에 지대(至大)한 효과(效果)를 나타내었다. 본(本) 실험(實驗)의 3가지 처리중(處理中) Pt 접종분묘(接種盆苗)는 일차측근(一次側根)의 수(數)와 길이, 수고생장(樹高生長), 근부직경(根部直經), 엽면적(葉面積)의 발달(發達)에 현저(顯著)하게 나타나는 유의적인(有意的)인 인자(因子)였다. 그러나 균근(菌根)을 접종(接種)하지 않은 상수리나무 분묘(盆苗)는 외생균근(外生菌根)의 형성(形成)을 볼 수 없었다. 또 Pt 접종분묘(接種盆苗)에 있어서 외생균근(外生菌根)의 접종(接種)은 71.1%였으며, 대부분 외생균근(外生菌根)은 분(盆)의 상부(上部)와 하부(下部)보다는 분(盆)의 중앙부위(中央部位)에서 증가(增加)하는 경향(傾向)을 보였다.

• 농업과학연구
• /
• 제10권2호
• /
• pp.263-268
• /
• 1983

1. 충남(忠南) 각지(各地)에서 수집(收集)한 28개(個) 콩종자(種子) sample을 blotter법(法)으로 조사(調査)하였던 바 21종(種)의 균류(菌類)가 검출(檢出)되었고, 특히 부생균(腐生菌)인 Alternaria alternata, Aspergillus spp., Penicillium spp. 등(等)과, 자주빛무늬병균(病菌) (Cercospora kikuchii) 및 Fusarium spp. 이 많이 검출(檢出)되었다. 2. 자주빛무늬가 있는 종자(種子)에서는 무늬가 없는 종자(種子)에 비(比)하여 C. kikuchii가 많이 검출(檢出)되었고 반면(反面)에 Aspergillus spp.나 Penicillium spp.와 같은 부생균(腐生菌)의 오염율(汚染率)과 Phomopsis sp. 및 Fusarium 균(菌)의 이병율(罹病率)이 낮았다. 3. 병원성실험(病原性實驗) 결과(結果) Cercospora kikuchii, Colletotrichum dematium, Fusarium moniliforme, F. oxysporum, F. semitectum, Phomopsls sp.는 병원성(病原性)을 나타내었으나, F. equiseti와 F. solani는 병원성(病原性)이 없었다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.266-266
• /
• 2017

In recent years, adoption of the System of Rice Intensification (SRI) is spreading in most Asian countries, and more recently in Cambodia is one of the Asian countries with high adoptions of SRI. We conducted on-farm experiment to investigate the effects of SRI on rice growth and yield in the farmers' fields in rainfed region of southern Cambodia. The study was undertaken in rainfed lowland fields of Popel commune ($11^{\circ}$ 04' 67" N, $104^{\circ}$ 40' 79" E) of Tram Kak District in Takeo Province during the wet seasons in 2012, 2013, and 2015. A total of 32 on-farm experiments were conducted during the wet seasons for three years of 2012 (11 fields), 2013 (8 fields), and 2015 (13 fields). Across the three years of study, SRI produced significantly greater plant biomass and grain yield than Non-SRI. The yield increase was mostly ascribed for the increased number of grains per land area, which was due to the increased number of spikelets per panicle rather than the number of panicles per land area. With no significant difference between SRI and Non-SRI with respect to seedling age, the greater number of grains per panicle was accounted for by the reduced planting density and increased amount of manure application in SRI than Non-SRI fields. It was found that the greater manure application has increased soil nitrogen content in SRI and Non-SRI fields. While SRI did not increase the number of panicles per land area, it did increase the number of panicles per hill.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.182-182
• /
• 2017

The objective of this research was to determine controlling effects on rice blast (Pyricularia oryzae) in rice plants by using plant extracts from different extraction methods (water, boiling water, fermentation, and ethanol) from 38 agricultural materials of traditional agriculture. Rice blast was completely suppressed by 3% ethanol extracts in Rheum palmatum roots, and suppressed 97% and 77% by 10% ethanol extracts in onion bulb and pine tree leaves, respectively in a laboratory test. However, other agricultural materials showed low effect on suppression of rice blast. Additionally, in a seedling test, rice injury of two cultivars (Ilmibyeo and Hopyoungbyeo) against rice blast was reduced 40-71%, 29-63%, and 23-63% by 5 and 10% ethanol extracts in Rheum palmatum roots, onion bulb, and pine tree leaves, respectively, compared with non-treated controls. Rice injury of two cultivars (Ilmibyeo and Hopyoungbyeo) against rice blast was reduced by 21-55%, 23-46%, and 5-39% in response to Rheum palmatum roots, onion bulb, and pine tree leaf applications at 100, 200 and $400g/m^2$ at 0 day after seeding, respectively, compared with non-treated controls. Rice plants did not show any leaf injuries and growth reduction after treatments of the Rheum palmatum roots, onion bulb, and pine tree leaf extracts or soil application. Thus, the above materials may be used for controlling rice blast in organically produced rice fields.

• 식물조직배양학회지
• /
• 제21권1호
• /
• pp.1-6
• /
• 1994

멜론의 배발생 캘러스의 유도와 식물체 재분화 시스템을 확립하기 위해서 자엽과 배축의 절편을 여러 농도의 2,4-D 와 BA가 첨가된 MS 기본배지에 치상하여 관찰한 결과, 초기배양에서는 4 mg/L 2,4-D와 1 mg/L BA 그리고 2 mg/L 2,4-D+O.1 mg/L BA가 첨가된 배지에서 연한 노란색의 배발생 캘러스가 형성되었고, 위의 조건에서 형성된 캘러스로부터 배발생 캘러스는 0.5와 1 mg/L 2,4-D가 첨가된 동일배지에서 약 75%가 형성되었다. 그리고 생장조절제를 첨가하지 않은 기본배지에서 대부분의 체세포배는 식물체로 재분화되었으며, 두개의 자엽을 갖춘 정상적인 체세포배보다 비정상적인 나팔형의 자엽을 가진 것이 3배 높은 빈도로 나타났다. 이러한 체세포배들은 MS 기본배지에서 식물체로 발아되었으며 생육상에서 생장하여 견실한 열매를 맺었다.

• Journal of Plant Biotechnology
• /
• 제3권2호
• /
• pp.95-100
• /
• 2001

To select the section with shoot formation ability, the calli and shoot formation from three sections (first leaf including cotyledonary node, hypocotyl and cotyledon explants) of 5-days-seedlings of soybean were induced on MS medium supplemented with 1.0 mg/L BAP, 3% sucrose, and 0.3% gelrite for one month. The first leaf section exhibited the highest shoot formation rate (51%), followed the hypocotyl section (10%) and the cotyledon section (0%). The shoot formation rates and shoot number of the four excised sections (whole first leaf, a half of the first leaf, a third of the first leaf and only node) of the first leaf were also investigated on the same medium. A half of the first leaf explant and the third of the first leaf explant had higher shoot formation rates (76-80%) and numbers (3-4 / explants) than those in other two explants. Effects of six cytokinins (kinetin, zeatin, BAP, 2iP, PBA, and TDZ) on shoot formation were determined, using the half of the first leaf explants. Zeatin (1.0 mg/L) exhibited the highest in shoot formation rate (94%) and numbers (8 / explant). In addition, the combined effects of three cytokinins (zeatin, BAP, and TDZ; 0.5, 1.0, 2.0 mg/L, respectively) and an auxin (IAA; 0.0, 0.5, 1.0, 2.0 mg/L) were determined. The combination (1:1, v/v) of zeatin (1.0 mg/L) and IAA (1.0 mg/L) exhibited the highest in shoot formation rate (96%) and numbers (16 / explant), twice more than zeatin (1.0 mg/L) alone. The shoot cuttings were transferred and cultivated on the rooting media supplemented with only auxin, IBA at various concentrations. The highest root formation (8 / shoot) was achieved on the medium supplemented with 1.5 mg/L. After 4 weeks of cultivation, the plantlets with an extensive root system were transplanted in pots with a soil mixture of vermiculite and fine sand. Transferred to field, about 75% of the plantlets survived.

• The Plant Pathology Journal
• /
• 제20권1호
• /
• pp.63-66
• /
• 2004

Ginseng (Panax ginseng) is one of the most widely cultivated medicinal herbs in Korea. However, yield losses reached up to 30-60％ due to various diseases during 3 or 5 years of ginseng cultivation in the country. Therefore, successful production of ginseng roots depends primarily on the control of diseases. The objective of this study was to select potential biocontrol agents from rhizobacteria isolated from various plant internal root tissues for the control of multiple ginseng diseases as an alternative to fungicides. Among 106 Bacillus strains, two promising biocontrol agents, Bacillus pumilus strain B1141 and Paenibacillus lentimobus strain B1146, were selected by screening against root rot of ginseng caused by Cylindrocarpon destructans in a greenhouse. Pre-inoculation of selected isolates to seed or l-year-old root of ginseng resulted in stimulation of shoot and/or root growth of seedlings, and successfully controlled root rot caused by C. destructans (P<0.05). Furthermore, drenching of cell suspension of the selected isolates on seedling-growing pots reduced the incidence of Phytophthora blight after the seedlings were challenged with zoospores of Phytophthora cactorum (P<0.05). P. lentimorbus strain B1146 showed antifungal activity against various soil-borne pathogens in vitro, while B. pumilus strain B1141 did not show any. Results of this study suggest that some rhizobacteria can induce resistance against various plant diseases on ginseng.

• Journal of Biosystems Engineering
• /
• 제30권2호
• /
• pp.81-88
• /
• 2005

Manual transplanting Chinese cabbage needs 184 hours per ha in Korea. Mechanization of Chinese cabbage transplanting operation has been highly required because it needs highly intensive labor during peak season. This study was conducted to developed walking-type Chinese cabbage transplanter. In order to find out design factor of the transplanter, a kinematic analysis software, RecurDyn, was used. The prototype was tested in the circular soil bin and its operating motion was captured and analyzed using high speed camera system. Prototype was one row type which utilized original parts of engine, transmission and etc. from walking-type rice transplanter in order to save the manufacturing cost. Success ratio of pick-up device of hole-pin type and latch type were $96.0\%$ and $99.2\%$, respectively. which was highly affected by feeding accuracy of feeding device of seedling. Transplanting device of the prototype produced a elliptic loci which were coincident with those produced by the computer simulation. Prototype proved good performance in transplanting with mulching and without mulching operation, either. Working performance of prototype was 22 hours per ha and operation cost of the prototype was 961,757 won per ha. So, it would reduce $88\%$ of the labor and $29\%$ of operation cost.