• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.317-323
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• 2012

This study was performed in order to explore the growth characteristics by growing stage in the containerized seedling and the bare root seedling of Chamaecyparis obtusa Sieb. et Zucc., which is the major plantation species of Korean southland. The height growth of 1-year-old bare root seedlings was better than containerized seedlings, which grew in the containers with capacity of 31.2 mL and 300 mL. The root collar diameter growth was the best in the containerized seedlings of container with 300 mL. The 2-year-old bare root seedlings were surveyed to be better in the height and root collar diameter growth than the containerized seedlings of container with 300 mL. In the comparison of dry mass production, it was the highest in 32 mL containerized seedlings as for 1-year-old above ground and in 300 mL containerized seedlings as for below-ground and total dry mass production. In case of 2-year-old seedlings, it was indicated to be high in bare root seedling as for the part above ground and in dry mass production of the containerized seedling as for the part below ground. In the comparison on root morphological traits of seedlings such as the total root length, the root project area, the root surface area, the average diameter in root, and the root volume, all of 1 and 2-year -old containerized seedlings showed the higher growth than the bare root seedlings except the average diameter in root. Synthesizing the results of this experiment, the containerized seedlings are relatively excellent in root development compared to bare root seedlings in the process of producing seedlings of C. obtusa, thereby being judged to have grown into excellent seedlings.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.771-778
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• 2016

Seedless grape (Vitis spp.) cultivars with large berries can be developed from hypo- and hypertetraploid seedlings. The low occurrence of hypo- and hypertetraploid seedlings, however, has impeded the breeding of new hypo- and hypertetraploid grape varieties. In order to establish hypoand hypertetraploid seedlings, we examined the chromosome numbers in seedlings of self-, open-, and cross-pollinated hypotetraploid 'Takao' and hypertetraploid 'RB9127K' grape. Three of the five seedlings (60%) from 'Takao' were aneuploid, including one with 74 chromosomes (2n=4x-2) and two with 75 chromosomes (2n=4x-1). In 'RB9127K', 26 of the 193 seedlings (13.5%) were aneuploid, including three seedlings with 75 chromosomes (2n=4x-1), 18 with 77 chromosomes (2n=4x+1), and five with 78 chromosomes (2n=4x+2). The high frequency of aneuploids from 'Takao' and 'RB9127K' grape indicates that meiosis in hypo- and hypertetraploid female parents is prone to segregation error. These results suggest that various hypo- or hypertetraploid seedlings can be successfully produced using hypo- or hypertetraploid grapes as female parents, which can contribute to the development of new seedless grape varieties with large berries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.192-198
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• 2020

Root extension is the most important growth change that occurs during cultivation. We analyzed growth changes according to young seedling age, temperature, and the degree of root cutting in order to identify factors affecting rooting after transplanting. Root cutting did not affect plant height growth rate, root growth rate was increased in plants that experienced root cutting, and 14-day-old seedlings exhibited a higher growth rate than 7-day-old seedlings. Growth temperature experiments revealed that elongation was high at 25℃ and 28℃, but tended to be low at 18℃, and root elongation was high at 22-28℃ for 7-day-old seedlings and 22-25℃ for 14-day-old seedlings. Nitrogen absorption decreased in the following growth temperature order: 25, 28, 22, 18℃, and differences in nitrogen absorption under different growth temperatures tended to be lower in 7-day-old seedlings. The amount of nitrogen taken up by roots did not differ significantly between the short root treatment and the control, and 7-day-old seedlings tended to start nitrogen absorption faster than 14-day-old seedlings. Root vitality was highest in short-rooted 7-day-old seedlings with 3 cm of root remaining, and vitality also tended to be high in short-rooted 14-day-old seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.55-59
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• 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.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.135-138
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• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.322-328
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• 2006

A series of methanol extracts from leaf and root parts in spring- and winter-barley plants were assayed to determine their allelopathy and antioxidant activity. The methanol extracts applied on filter paper in a Petri-dish significantly inhibited root growth of Chinese milkvetch (Astragalus sinicus L.) seedlings. Leaf extracts at 25 and 50 g $L^{-1}$ inhibited root growth of Chinese milkvetch seedlings more than root extracts. No difference in phytotoxic effects of spring- and winter-barley seedlings extracts on root growth of Chinese milkvetch was observed. Methanol extracts dose-dependently increased DPPH free radical scavenging activity in vitro. DPPH free radical scavenging activity was higher in the methanol extracts from winter-barley seedlings than in those from spring-barley seedlings, and from leaf extracts than from root extracts. The antioxidant potential of the individual fraction from the methanol extracts of spring-barley seedlings was in order of n-butanol>ethyl acetate>water>chloroform>n-hexane fraction. By means of HPLC analysis, spring-barley (200.62 mg $100g^{-1}$) had more amount of total phenol acid than winter-barley (114.08 mg $100g^{-1}$). Especially, ferulic acid was detected in spring-barley extract (183.46 mg $100g^{-1}$) as the greatest amount. These results suggest that early seedlings of barley plants had potent allelopathy and antioxidant activity, and their activities were differently exhibited depending on plant parts and growing condition.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.629-634
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• 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.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.251-257
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• 2011

The purpose of this study was to investigate the acclimation responses of Tamarix chinensis to cold stress. We evaluated the acclimation responses by measuring biomass, daily elongation rate, chlorophyll content, and total soluble carbohydrate content. The plant samples comprised leaves from seedlings of 2 different ages (8 and 12 weeks); the leaves were collected 0, 2, and 4 weeks after cold treatment. We found that the cold-treated samples showed reduced daily elongation rates and chlorophyll content. Further, these samples showed more than 8-fold increase in the total soluble carbohydrate content. However, the seedling ages did not have a significant influence on the growth of cold-treated seedlings. On the basis of these findings, we can conclude that T. chinensis seedlings aged less than 1 year old show acclimation to cold stress by accumulating soluble carbohydrates. This study may help us understand how T. chinensis seedlings acclimatize to their first cold season.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.122-128
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• 1999

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.

• Forest Science and Technology
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• v.14 no.4
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• pp.153-159
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• 2018

Seedlings of Pterocarpus indicus were grown in both well-watered and drought stress conditions in phytotron. Seedlings grown under well-watered and drought stress conditions were exposed to either combined or without ozone of 200 ppb for one month. First, the physiological responses to elevated ozone levels indicated a decreased biomass. The seedlings grown in arid soil and exposed to ozone showed less biomass than those grown in arid soil but not exposed to ozone. Moreover, all the seedlings except the well-watered and unexposed ones showed a significantly lower photosynthetic rate ($P_N$) over time. However, with the accumulation of ozone injuries, the antioxidant enzyme activities increased overall. In the study results, when exposed to ozone, the well-watered seedlings exhibited more antioxidative enzyme activity than did the seedlings grown in arid soil. Generally, P. indicus in arid soil suffered less damage from elevated ozone than did the well-watered plants.