• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.977-986
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• 1996

The uncertainty of rains at the onset of wet season (WS) and the drought risk involved hinder growing more than one rainfed lwoland rice crop per year. Establishing transplanted rice well into the WS leaves insufficient moisture in the soil for subsequent crop. Rice establishment early in the season gives the farmer better opportunities to grow a crop after rice. An experiment was conducted startign in 1993 to evaluate dry seeding of rice through slit soil seeding. It is done utilizing the vertical metering slit seeder for conserving soil moisture coming from the first rains in the early WS to sustain germination and establishment of the seeding at least until the succeeding rains under therainfed lowland (RL) environment. The treatment consisted of slit-seeding the PSBRc 14 into the tilled and nontilled plots at 100kg/ha and at depths of <10 mm (shallow seeding) and 60-70m (deep seeding). The control treatment was broadcast seeded on tilled soil and harrow to cover the seeds The superior crop establishment observed in 1995 WS experiment on nontilled, slit-seeded plots confirmed the results observed in 1993 WS and 1994 WS experiments. Emergence in deep seeding was not significantly different from shallow seeding in nontilled plots giving an average yield of 2.1 t/ha in all slit-seeded plots. This offers an advantage of reduced energy in put in nontilled shallow seeding. However, heavy weed infestation has to be addressed at the early stage of rice in nontilled soil to get the full advantage from slit seeding. The consistently better crop establishment observed in slit seeding over that of broadcast seeding in the WS of 1993, 1994 and 1995 also demonstrates that the slit seeding technology can be adopted with confidence in the rainfed lowland field condition to reduce the risks involved in broadcast seeding.

• 한국잡초학회지
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• 제15권4호
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• pp.247-253
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• 1995

The herbicide butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-di-methylphenyl) acetamide] is widely used by farmers as a tool for weed management of transplanted rice(Oryza sativa L.) in Taiwan. The herbicide did not stop germination of rice and weed seeds, but strongly inhibited the subsequent growth of young shoots and roots. The inhibition was also strong on established seedlings. However, they could recover to normal growth after the herbicide effect disappeared. Butachlor greatly decreased the endogenous indole-3-acetic acid (IAA) but increased the endogenous abscisic acid (ABA) contents of rice seedlings. Addition of lAA into growth medium (Hoagland's solution) partly relieved growth inhibition. Pretreatment of both gibberellic acid ($GA_3$) and IAA 24 hours before butachlor treatment almost completely alleviated the butachlor-interfere with GA and/or IAA metabolism or their action resulting in the growth inhibition of rice. Butachlor was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicide was absorbed. Pretreatment of the herbicide for 2 days did ncx affect the absorption. Of the absorbed herbicide, 80% remained in roots, only 20% transported into shoots, and more than 50% was metabolized to water soluble substances. Thin-layer chromatographic (TLC) analysis indicated that the Rf value of the most abundant metabolite was butachlor-glutathione conjugate. Rice, barnyardgrass (Echinochloa crus-galli (L.) Beauv.), and monochoria (Monochoria vaginalis Presl) seedlings contained relatively high level of non-protein thiols, while the glutathione S-transferase (GST) activity was found highest in rice, barnyardgrass the next, monochoria the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.

• 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.

• 생명과학회지
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• 제14권4호
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• pp.644-649
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• 2004

GA 생합성에 결정적 역할을 하는 GA 3$\beta$-hydroxylase를 pIG121-Hm 벡터에 GUS유전자를 빼고 antisense로 클로닝하여 이를 동진벼에 도입한 결과 17개체의 절간신장이 억제된 형질전환한 식물체를 얻을 수 있었다. 일반 재배 동진벼를 대조군으로 하여 비교하였을때 antisense GA 3$\beta$-hydroxylase 유전자가 형질 도입된 식물체의 획득형질은 평균적으로 대조군에 비해 절간 신장의 억제가 확인되었다. 절간신장의 억제가 보인 개체의 엽육조직을 co취하여 Southen blot hybridization분석 결과 3개의 line에서 모두 single copy로 도입된 것으로 나타났다. 이로써$T_o$ 식물체 내에 antisense GA 3$\beta$-hydroxylase 유전자를 내포하고 있는 것으로 확인되었다. 이것은 antisense GA 3$\beta$-hydroxylase 유전자가 생체내에서 직접 또는 간접적으로 GA 3$\beta$-hydroxylase유전자의 발현에 관여한 것이라 사료되어진다.

• Applied Biological Chemistry
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• 제3권
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• pp.1-7
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• 1962

In order to study the rate control step in the protein metabolic course of the chlorophyll formation, the transaminase activities which are obtained freely in the extracts of cotyledons of germinating peas at the light and the dark places, are measured in Beckman mopel D.U, spectrophoto meter at 490 mu. In this case, of two enzymatic reaction products; oxalacetic acid and pyruvic acid, the former is converted to pyruvic acid by aniline citrate and after each pyruvate phenyl hydrazones are extracted by toluenes: when this is treated with strong alcoholic alkali, a colored hydrazone is formed and it is measured by above apparatus. The estimated G.O.T. and G.P.T. in the germinated cotyledons at dark and light places considerably differ in their activities; G.O.T. and G.P.T. activities which are formed at the light are more increased than at the dark and also they differ in their rates through germination, though G.O.T. activity increment is smoothly but that of G.P.T. is more sharply, and they are considered to be directly affected to the chlorophyll formation and indirectly to the growth. G.O.T. and G.P.T. in each fractions of cell in the cotyledons should be formed by dissociation of zymogens in the microsomal fractions and it seems to promoted by light. In the formation of the chlorophyll, the protein metabolism occurred mainly in the microsomal fractions and the rate determining step is found at the point where the zymogene that is able to produce G.P.T. is activated, and this activation is promoted by light as noted above.

• Journal of Plant Biology
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• 제35권3호
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• pp.265-271
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• 1992

대두의 발아 후 초기 생장 단계의 조직에서 IAA가 DAO에 미치는 영향에 관하여 조사하였다. DAO의 활성은 발아전 자엽에서는 나타나지 않으나 발아 후 3일된 조직에 나타나기 시작하여 4일된 조직에서 가장 높았고 이후 다시 감소되는 경향을 보였다. 내생 IAA 함량도 4일된 조직에서 가장 높았다. 그러나, cadaverine의 함량은 4일된 조직에서 감소하였다. IAA가 DAO에 미치는 영향을 조사하기 위하여 3일된 조직에 다양한 농도로 처리하였다. 저농도($10^{-7}-10^{-6}M$) IAA 처리구에서는 대조구에 비하여 활성이 증가하였으나 고농도($10^{-5}-10^{-4}M$) IAA 처리구에서는 대조구와 유사한 활성이 조사되었다. DAO의 활성 변화와는 달리 cadaverine의 함량은 고농도 IAA 처리구에서 증가하였다. 한편, 고농도 IAA 처리구에서는 에틸렌이 발생하였다. 따라서, 에틸렌이 DAO의 활성에 미치는 영향을 보기 위하여 NDE를 처리한 결과 DAO의 활성에는 아무런 영향도 미치지 않는 것으로 나타났다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제1권1호
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• pp.22-30
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• 2020

Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested.

• Applied Biological Chemistry
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• 제26권1호
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• pp.28-34
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• 1983

발아초기(發芽初期)에 콩(대두(大豆))의 부위별(部位別)로 Lactate dehydrogenase(LDH)의 Isozyme 존재가능성(存在可能性)을 조사(調査)하기 위한 기초적(基礎的)인 연구(硏究)가 수행(遂行)되었다. 발아가 진행(進行)됨에 따라 자엽부위의 효소활성변화(酵素活性變化)에는 큰 유의성이 나타나지 않았으나, 배축이나 뿌리 부위(部位)에서는 감소하는 경향을 보였으며 $4{\sim}7^{\circ}C$에서 배축이나 뿌리로부터 얻은 LDH는 자엽에서 얻은 LDH에 비(比)해 불안정(不安定)했다. 전기영동상의 Rm value가 자엽으로부터 얻은 효소(酵素)에서는 0.25인데 비하여, 배축으로 부터 분리된 LDH는 0.29였다. 배축이나 뿌리로 부터 분리된 LDH는 Biphasic으로 0.45mM과 0.014mM의 두 km값을 보이고 자엽부위에서는 0.45mM 값만 관찰할 수 있었다. 이상의 결과는 자엽부위의 LDH와는 다른 성질(性質)을 가진 LDH가 배축이나 뿌리부위(部位)에 존재(存在)할 가능성(可能性)을 보여주고 있다.

• 한국자원식물학회지
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• 제11권1호
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• pp.101-105
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• 1998

우리나라 황칠나무의 자생지인 전남 완도지방에서 황칠나무의 재배시 종자의 발아율을 향상시키는 방법을 구명하고자 본 시험을 실시한 결과는 다음과 같다. 황칠나무의 열매는 핵과로서 자방의 길이가 7.8~10.7mm였으며, 자방폭은 6.9~9.0mm의 타원형이었다. 자방은 5실로 구분되어 있었고, 1실에는 각각 1개의 종자가 형성되었다. 따라서 자방 1개에는 5개의 종자가 들어있으며, 5개의 종자중의 1개종자는 배유가 형성되지 않은 무배유 종자로 발아가 이루어지지 않았다. 황칠나무의 종자는 길이가 6.3~7.4mm였으며, 종자폭은 2.0~2.9mm이었고, 종자의 100립중은 1.43~1.80g이었다. 황칠나무 종자의 발아율을 향상하기 위해서는 채종 즉시 가을파종은 $40^{\circ}C$온탕에 90분~120분간 침지한 후 파종을 하면 종자의 발아율이 향상될 것으로 판단된다. 또한 종자 저장후 봄파종은 $10^{\circ}C$의 온도에 60일~90일정도 저장한 후 파종하면 발아율을 높일 수 있을 것으로 생각된다.

• 한국환경농학회지
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• 제16권4호
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• pp.390-393
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• 1997

식물생육에 대한 저선량 방사선의 효과를 보고자, 배추 세품종과 무종자에 ${\gamma}$선을 조사한 후, 온실과 포장에서 재배하여 그 생육상황을 조사한 결과는 다음과 같다. 저선량 ${\gamma}$선이 배추와 무의 발아율과 유묘초장등에서 초기생육을 촉진하는 효과가 인정되었으며, 그 효과는 품종에 따라 달랐다. 유묘초장의 경우는 서림배추와 알타리무는 0.2Gy에서, 고랭지 여름배추는 1Gy에서, 덕성배추는 4Gy에서 가장 높았다. 포장재배한 서림배추와 무의 초장은 1Gy에서, 덕성배추는 4Gy에서 가장 높았고, 생체중은 배추와 무 모두 4Gy에서 가장 양호하였다.