• 제목/요약/키워드: seedling size

검색결과 194건 처리시간 0.028초

Effect of Seeding Depth and of Soil Texture on Seeding Emergence and Root Shape of American Ginseng

  • Li, Thomas S.C.
    • Journal of Ginseng Research
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    • 제21권2호
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    • pp.115-118
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    • 1997
  • Stratified American ginseng(Panax quinquefoilium L.) seeds were planted in a shaded greenhouse at four depths and in four different soil types to observe effects on emergence rate and root size. Seeding depth affected seedling emergence rates and the number of days required to complete emergence. The shape of the roots was affected by the texture of soil, especially percentage of sand.

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Effects of Organic Manure on Seedling Growth and Nodulation Capabilities of Five Popular Leguminous Agroforestry Tree Components of Bangladesh

  • Uddin, Mohammad Belal;Mukul, Sharif Ahmed;Hossain, Mohammed Kamal
    • Journal of Forest and Environmental Science
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    • 제28권4호
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    • pp.212-219
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    • 2012
  • An experiment was set to understand the seedlings growth and nodulation capabilities of five potentially important leguminous agroforestry tree species of Bangladesh in response to application of organic fertilizer. Study was carried out in nursery bed on the seedlings of Acacia mangium Willd., Acacia hybrid, Acacia auriculiformis A. Cunn. ex Benth, Albizia lebbeck (L.) Benth. and Leucaena leucocephala (Lam.) de Wit. after sowing their seeds in polybags filled with different medium. Farmyard manure or decomposed cow dung was applied as the source of organic fertilizer with other potting media. The growth and nodulation performance of seedlings of the selected species were measured three moths after the first seed was emerged. The different soil: organic manure ratios' used during the experiment were, 1:1, 2:1 and 3:1. The effects of organic fertilizer on growth and nodulation were compared to that of seedlings grown in control. The results revealed a positive correlation between seedling growth and the different doses of organic fertilization (i.e. seedling growth was enhanced significantly with different treatments containing higher proportion of organic fertilizer). In few cases a negative effect was observed after applying higher levels of organic manure. It was also apparent that the nodulation in terms of nodule number and size was inhibited significantly by the application of organic fertilizer.

Population Dynamics of Quercus mongolica in Mt. Jumbong

  • Cho, Do-Soon
    • The Korean Journal of Ecology
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    • 제22권6호
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    • pp.355-361
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    • 1999
  • Distribution of size class, population regeneration and changes in the population structure of Quercus mongolica were studied from 1994 to 1999 in Mt. Jumbong (128°27' E, 38° 04' N) of Mt. Sorak National Park and Biosphere Reserve in central Korea. Three 20m × 20m permanent quadrats were set up at the elevation of 900m. The vegetation of the study site was dominated by Quercus mongolica and Acer pseudosieboldianum, but little change was observed in the community structure from 1995 to 1999. Most mortality in the study site was observed in small trees of A. pseudosieboldianum and Tilia amurensis. Mean annual growth in dbh (diameter of breast height) of Q. mongolica for 4 years was only 0.09cm, and no ingrowth of saplings (dbh < 2.5cm) into tree class was observed during the study period. Among the 21 Q. mongolica trees studied in the permanent quadrats. all the smaller trees (dbh < 30cm) were established in 1920 ∼ 1950, while many bigger trees (with 40cm < dbh < 80cm) were established in 1750 ∼ 1800, indicating that its establishment was episodic. Distribution of dbh classes among Q. mongolica trees shows that smaller trees were poorly represented, and no saplings of Q. mongolica occurred in the permanent quadrats studied, indicating that currently Q. mongolica is not regenerating well in the study site. Total seed production of Q. mongolica in 1994 was estimated as 88 acorns per square meter in the study site. Rate of predation including caching of acorns was highest in 1994, then declined sharply thereafter. Most of the acorns which managed to survive in the first year were predated in the second year, and only 5% of the acorns produced in 1994 survived into the third year. No seeds produced in 1994 or seedlings germinated from them succeeded to survive to 5 years after seed production. However, seedling emergence rate and seedling survival were high in the early growing season in 1995. These results suggest that predation can be a significant factor in the regeneration of Q. mongolica. and that Q. mongolica is not regenerating well in Mt. Jumbong and needs large scale disturbances for its new recruitment.

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고추 유묘에 대한 Colletotrichum acutatum의 병원성과 탄저병 발생 (Pathogenicity and Occurrence of Pepper Seedling Anthracnose Caused by Colletotrichum acutatum)

  • 한경숙;박종한;한유경;황정환
    • 식물병연구
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    • 제15권2호
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    • pp.88-93
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    • 2009
  • 고추 유묘의 신초가 말라죽고 잎에 수침상점무의 증상으로부터 병원균을 분리하여 균총의 색깔과 형태, 포자의 모양과 크기를 관찰한 결과 균총의 색깔은 처음에는 핑크색 띄나 차츰 회색으로 변하였고, 분생포자는 방추형으로 크기가 $8.1-17.0{\times}2.0-3.8{\mu}m$이며 생장최적온도 $25-27^{\circ}C$이다. 종 특이적 프라이머를 이용하여 고추 유묘에서 분리한 균을 동정한 결과 C. acutatum에 특이적인 프라이머인 CaINT에서만 496 bp의 증폭산물을 얻었다. 이들 결과를 바탕으로 유묘에서 분리한 균은 Collectotrichum acutatum으로 동정하였다. 고추 유묘에서 분리한 균주를 고추묘 생육단계별로 병원성 검정한 결과 유묘 뿐 아니라 식물체 전 생육기에 잎 탄저병 증상을 나타내었으며 또한 고추 열매에서도 강한 병원성을 나타내었다.

Identification of Genes Induced by Low Temperature in Rice

  • Choi, Kyong-Hee;Choi, Hack-Sun;Lee, Choon-Hwan;Kwon, Young-Myung;Rhew, Tae-Hyong
    • BMB Reports
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    • 제30권4호
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    • pp.292-295
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    • 1997
  • Exposure of seedling of rice (Oriza sativa cv.Dongin) to cold stress ($6^{circ}C$, 7day) induced differential gene expression. Differentially expressed polyadenylated RNA induced by low temperature were isolated and identified from the leaves of rice (Oriza sativa cv.Dongin) seedling by using the technique, differential display of reverse transcription through polymerase chain reaction (DDRT-PCR). Four bands of cDNAs were differentially displayed on the PAGE gel through DDRT-PCR, and among them three bands were those of overexpressed genes while one band was of an underexpressed gene One of the overexpressed cDNA was characterized. The size of the DDRT-PCR product was found to be about 200 bp. The sequence of the cloned DNA was compared with those of GenBank through a BLAST E-Mail server, and it was found to have no homologies in the nucleotide sequence with that of any known DNA: therefore, it was designated as RC101 The expression of the cold-stress induced-gene, RC101, was sustained with Northern Blot analysis by using the cloned DDRT-PCR product as a probe.

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Evaluation Method of Weed Suppression by Rice Plant

  • Lee Sang-Bok;Ku Yeon Chung;Seong Ki Young;Song Duck Young;Seo Kyung In;Shin Jin Chul
    • 한국작물학회지
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    • 제50권2호
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    • pp.79-83
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    • 2005
  • Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above $3\~4cm$ from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of $2.5\times2.5cm$ at rice clipping of seedling 29 days after rice seeding.

Effect of Deep Sea Water on Seed Germination, Photoperiod and Temperature on the Growth and Flowering of Buckwheat Species

  • Briatia, Xoxiong;Hong, Soon-Kwan;Sung, In-Je;Chang, Kwang-Jin;Park, Byoung-Jae;Park, Cheol-Ho
    • 한국자원식물학회지
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    • 제25권3호
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    • pp.323-328
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    • 2012
  • This paper describes the potential use of deep sea water to stimulate seed germination in both common and Tartary buckwheat. Treatment of 10% deep sea water at $25^{\circ}C$ would slightly enhance germination of buckwheat seeds compared to non-DSW treatment and other temperature. In this study, the significant effects of photoperiod and temperature on seedling growth were also found in the HL treatment for the number of leaf, plant height, and plant fresh weight and LL treatment for root length and leaf size. Common buckwheat (Suwon No.1) showed higher rate (93%) of flowering plants in the HS and LL (93% of flowering rates) than those revealed in the HS and LS treatment, while the low percentage(67%) of plant flowering plants was shown in the LS treatment. All plants (100%) of a Korean landrace, Ahndong-jaerae showed flowers in the HS and LS treatment. HL and LL treatment status did not occur in the plant's flowering. Any Tartary buckwheat (KW45) plant did not yet flowered when it was 21 days-old.

한·중 어업자원관리제도에 관한 비교연구 (A Comparative Study on Fisheries Resource Management System between Korea and China)

  • 차철표
    • 수산해양교육연구
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    • 제13권2호
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    • pp.146-167
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    • 2001
  • Korea and China are two opposite countries located aside Yellow Sea and co-utilize the East China Sea. The two countries are close together from geological point of view, however, the competitive development of resources was more emphasized than the cooperative development of resources between the two countries because the special policy relationship. Additionally, after the communist government of China was founded in 1949, the political conception between the two countries was quite different. Therefore the establishment of appropriate international fisheries co-operation was impossible, and the international management problems of fisheries resources in Yellow Sea and East China Sea were let alone. UN convention on the Law of the Sea came to force in 1994, Korea and China adopted the exclusive economic zone system in 1996. On the other hand, Fisheries Law in Korea was enacted in 1953 in order to management of fisheries resources, and also China was enacted fisheries law in 1986. The two countries control the fisheries effort through fisheries license system, meanwhile through prohibition fishing area, prohibition fishing period, limitation of net size, and limitation of body length to conserve and manage the fisheries resource. The serious management methods of resource management in the two countries are similar such as the creation of promptly decreased species and those species that have commercial value, discharge of fish seedling stock, settlement of artificial reef and clean of fishing ground. Therefore, the two countries should consider not only the improvement of formal law system, but also how to recover the fisheries resources in circumference water zone and how to improve the efficiency of fisheries resource management. Specially the settlement and management of artificial reef should be chosen in the area that have the highest benefit to two countries, and should establish the common management system of discharge of fish seedling stock. And the two countries should adopt the same criteria through technical management and limitation of net size, limitation of body length, and prohibition area of special fisheries to ensure the highest fisheries benefit of fisherman in the two countries and the highest efficiency of fisheries resource management.

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땅콩 종실의 발육과 미숙종자의 발아력 (Seed Development and Germinability of Unripened Seed in Peanuts)

  • 김석동;이성우;박장환
    • 한국작물학회지
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    • 제42권3호
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    • pp.333-337
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    • 1997
  • 땅콩의 육종년한을 단축하기 위한 세대촉진 방법을 정립하고자 포장후건에서 신대광땅콩 및 남대땅콩을 재배하고, 자방병이 지하로 침투한 후부터 80일까지 10일 간격으로 꼬투리와 종실을 재취하여 그 크기와 무게, 수분함량의 변화를 추적하는 동시에 종실의 발아율과 발아한 유묘의 활력을 조사한 결과, 자방병이 지하로 침투한 후 30∼40일에 꼬투리와 종실의 크기가 완성되었고, 이 때에 수확한 종실은 100% 발아력을 갖추며 발아 후 활력있는 유묘를 생산할 수 있는 것으로 나타났다.

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