• Journal of Crop Science and Biotechnology
• /
• 제10권1호
• /
• pp.39-44
• /
• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.

• Journal of Biosystems Engineering
• /
• 제14권3호
• /
• pp.181-187
• /
• 1989

The mechanical and rheological properties of agricultural materials which influence the machine design or handling are not completely understood. Agricultural materials do not react in a purely elastic manner, and their responses when subjected to stress and strain appear a combination of elastic and viscous behavior. Many researchers have studied the mechanical and rheological properties of the various agricultural materials, but those properties are available mostly for foreign varieties of agricultural products. Rheological properties of rice seedlings become important to formulate the principles governing their mechanical behavior. The objectives of this study were to experimentally determine the creep and recovery behavior of rice seedlings of one japonica-type and one Indica x japonica hybrid in the transplanting age. The results of this study are summarized as follows; 1. The compression creep and recovery behavior of mat-type seedlings could be described by 4-element Burger's model. 2. The steady-state creep appeared at the stress larger than 0.8 MPa and the logarithmic creep appeared at the stress smaller than 0.8 MPa. 3. In the compression creep test of the rice seedlings, the instantaneous elastic modulus of Burger's model showed the range from 20 to 40 MPa. The higher value of absolute viscosity for the rice seedling explained that the rice seedlings were viscoelastic materials. 4. In the recovery test of the rice seedlings, there was a tendency that the higher permanent strain of all samples was observed under the smaller stress being appeared, and the larger permanent strain in Dongjin was observed than in Samkang.

• 한국작물학회지
• /
• 제50권1호
• /
• pp.55-59
• /
• 2005

Rice farmers can save labor and expenses by using expanded rice husk (ERH) as a seedling medium since ERH is lighter and cheaper than other commercial seedling media (CSM). This study was carried out to develop a method for rice seedling cultivation using ERH as a seedling medium. It is suggested that a mixture of $60\%$ of ERH and $40\%$ of a CSM could be used as a seedling medium; the planting densities would be 240g per tray for infant seedlings and 200 g for young seedlings; and nitrogen (N) would be applied at a rate of 1g per tray for infant seedlings prior to planting and 2g per tray for young seedlings with division. Great care should be taken to use $CO(NH_2)_2$ as an N-source fertilizer. These results would lay a foundation for the rice seedling cultivation with ERH as a medium.

• 한국유기농업학회지
• /
• 제19권spc호
• /
• pp.135-138
• /
• 2011

In traditional organic rice culture practices, control of weeds is a big problem. This study was conducted to increase the rice production. Results showed that Plant height, SPAD, root length and weight were higher in pot raised seedling than broadcasting method except number of panicles. High plant density caused reduction in plant height, number of culm and chlorophyll content of the rice. No lodging was observed in both methods. Thickness of third internode and culm length was more in pot raised seedlings at both sites. When organic material was used rice yield increased by 3.81%. Higher rice production (10%) was recorded in the fields planted with pot raised seedlings. From the above study it could be conclude that the pot raised seedlings perform better than the seedlings raised by broadcasting methods.

• Journal of Plant Biology
• /
• 제32권4호
• /
• pp.235-245
• /
• 1989

The contents and the compositions of total free amino acids were investigated in the rice(Oryza sativa L. cv. Chuncheong) seedlings under low temperatures. Activities of some enzymes associated with the markedly changed amino acid content were also investigaetd. Under low temperature, the contents of soluble protein and the total free amino acids increased, while the content of total nitrogen decreased. Although asparagine＋glycine were the most abundant amino acid speceis in the rice seedlings at the control temeprature, low temperature treatment for 3days brought about the decrease in their amount to about 60% level of the control plants. On the other hand, alanine showed the highest increase in the content among all the free amino acids, though glutamine, proline, asprtic acid, valine and tyrosine also increased after low temperature treatment. To eludicate the decrease of asparagine＋glycine level under low temperature, the activities of asparagine aminotransferase and asparaginase which metabolize asparagine were investigated in the rice seedlings under low temperature. The activity of asparaginase increased markedly, while that of asparagine aminotransferase decreased under low temperatures. Therefore, it was suggested that asparaginase metabolizes asparagine predominatly in the rice seedlings under low temperatures.

• 한국자원식물학회지
• /
• 제27권6호
• /
• pp.629-634
• /
• 2014

Rice type tartary buckwheat is used as a substitute for rice in many Asian countries due to its easy dehulling character. The objective of the present study was to determine the chlorophyll, total polyphenol (TP), total flavonoid (TF), antioxidant activity and to quantify the bioactive compounds rutin, quercetin and chlorogenic acid in the seedlings of rice-type tartary buckwheat (RTTB). Young seedlings exhibited higher antioxidant (DPPH radical inhibition) activity in dose dependent manner. TP and TF content were highest ($3017.46{\pm}201.84{\mu}g$ TAE/100 mg dw and $1916.0{\pm}102.95{\mu}g$ QE/100 mg dw respectively) in 3 days after germination (DAG) seedlings compare to 6 and 9 DAG. The contents of rutin and quercetin increased with growing stage of seedlings. However, the chlorogenic acid decreased with increasing growth. Overall, RTTB seedlings can be regarded as a strong source of phenolics and have high possibility for food and nutraceutical application due to their efficient antioxidant properties, higher chlorophyll and phytochemical content.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.187-187
• /
• 2017

Cadmium (Cd) pollution is rapidly increasing in worldwide due to industrialization and urbanization. In addition to its negative effects on the environment, Cd pollution adversely affects human health. Rice (Oryza sativa L.) is an important agricultural crop worldwide, including South Korea, and studies have examined its ability to alleviate Cd uptake from the soil into plants. However, information about the relationship between sulfur (S) and antioxidants in rice seedlings is still limited with regard to Cd phytotoxicity. We therefore investigated the changes in reactive oxygen species (ROS) and antioxidants in rice (Oryza sativa L. 'Dongjin') seedlings exposed to toxic Cd, S treatment, or both. The exposure of rice seedlings to $30{\mu}M$ Cd inhibited plant growth; increased the contents of superoxide, hydrogen peroxide, and malondialdehyde (MDA); and induced Cd uptake by the roots, stems, and leaves. Application of S to Cd-stressed seedlings decreased Cd-induced oxidative stress by increasing the capacity of the glutathione (GSH)-ascorbate (AsA) cycle, promoted S assimilation by increasing cysteine, GSH, and AsA contents in treated plants, and decreased Cd transfer from the roots to the stems and leaves. In conclusion, S application of plants under Cd stress promoted Cys and GSH biosynthesis and GSH-AsA cycle activity, thereby lowering the rate of Cd transfer to plant shoots and promoting the scavenging of the ROS that resulted from Cd toxicity, thus alleviating the overall Cd toxicity. Therefore, these results provide insights into the role of S in regulating the tolerance, uptake, and translocation of Cd in rice seedlings. The results of this study indicate that S application should have potential as a tool for mitigating Cd-stress in cereal crops, especially rice.

• Current Research on Agriculture and Life Sciences
• /
• 제18권
• /
• pp.53-60
• /
• 2000

벼 자동화 육묘시설에서 파종기별 알맞은 육묘기간을 선정하기 위하여 경상북도 안동, 의성 및 경산지역의 육묘시설에서 파종기와 육묘기간에 따른 묘소질, 육묘일수에 따른 수량구성요소와 수량성, 벼 품종별 묘소질 등을 조사 분석한 결과를 요약하면 다음과 같다. 자동화 육묘시설내에서 파종기가 늦어지고 육묘기간이 길어질수록 묘초장 신장 속도는 빨랐고, 지상부 건물중은 증가하였으나, 지상부건물 중/초장 비는 감소하였으며 그 감소폭은 10일묘 이후에서 컸다. 묘초장과 묘소질을 근거로 한 각 지역별 파종기에 따른 적정 육묘기간은 4월 하순 파종의 경우 안동과 의성에서는 15~20일묘, 경산은 15 일묘이고, 5월 하순과 6월 파종의 경우는 지역에 관계없이 10일묘가 적합하였다. 육묘 기간에 따른 수량성은 육묘일수가 10일에서 20일로 연장될수록 감소하였는데, 10일묘의 10 a당 수량은 관행중묘에 비해 5% 증수되었지만 20일묘의 경우는 9% 감소되었다. '대산벼'외 12품종을 대상으로 자동화 육묘시설에서의 묘생육을 비교한 바, 10일묘의 초장은 '상미벼', '원황벼' 및 '일품벼'는 13.3~13.5 cm로 짧은데 비해 '만안벼', '화영벼', '대산벼' 및 '일미벼'는 16.6~17.5 cm로 걸었는데, 이들 품종중 '화영벼'와 '대산벼'는 10일묘의 지상부 건툴 중도 9.1~9.4 mg으로 무겁고 육묘일수에 따른 지상부건물중/초장 비의 감소 폭도 작았다.

• 한국균학회지
• /
• 제13권1호
• /
• pp.23-26
• /
• 1985

묘대별발생(苗代別發生)을 보면 강한(江漢)찰벼와 낙동(洛東)벼에시 상자육묘(箱子育苗)가 보온절충묘대(保溫折衷苗代)보다 종자소독유무(種子消毒有無)에 관계(關係)없이 키다리 병(病)의 발생(發生)이 많았다. 상자육묘(箱子育苗)와 보온절충묘대(保溫折衷苗代)에서 자란 유묘(幼苗)를 일본(一本)씩 이앙(移秧)할 경우 본답(本畓)에서 상자육묘(箱子育苗)에서 자란 유묘(幼苗)가 보온절충묘대(保溫折衷苗代)에서 자란 유묘(幼苗)보다 이병률(罹病率)이 높았고 수량(收量)도 떨어졌다.

• Journal of Plant Biology
• /
• 제13권4호
• /
• pp.23-31
• /
• 1970

The rice variety, Kwanok, was reared in the water and land beds and transplanted to the reclaimed soil area, having an average salt concentration of 0.39%. Two levels of the moderate and late season cultures with 4 treatments were used. The K and Si contents of the stem part of land bed seedlings were somewhat smaller, but total carbohydrate remarkably larger, the C/N ratio was accordingly greater than water bed seedlings. The rooting ability of land bed seedlings was vigorous markedly in culture solutions, to which added various concentrations of NaCl, The rooting ability of each seedling water not much declined in theculturing solution of up to 9.4mmhos/cm, (0.6%) of salt concentration, but it was drastically declined in the salt concentration over that. It seemed that the critical salt concentration for the rooting rice plant. The land bed seedlings in each salty condition markedly decreased compared with the water bed seeldings in transpiration rate and it showed a stronger drought resistance and contained a large amount of chlorophyll at transplanting stage, and also showed higher stability of chlorophyll at rooting stage in the salt treatment. The number of panicles, panicle weight, number of grains per panicle and ratio of matured grains of the rice plant grown by the land bed seedlings were much greater and 1,000 grain weight was less than from water bed seedlings. The cultural practices with the land bed seedlings increased the rough rice yields by 15% and 11%, respectively, compared with the yields of the moderate and late season cultures by water bed seedlings.