• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.97-101
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• 1988

The objective of this paper was to examine the oxygen requriement of rice seeds when the seeds were germinating under the water. The trial was carried out in the laboratory with the different water temperature (25$^{\circ}C$, 17$^{\circ}C$) in the Crop Experiment Station, Suwon. The tested varieties were 6 in japonica and 6 in indica (I) ${\times}$ japonica (J). In the 25$^{\circ}C$ water temperature rice seeds absorbed more dissolved oxygen (DO) and germinating duration was shorter than in the 17$^{\circ}C$ water temperature. DO uptake of japonica rice seeds was faster than that of indica ${\times}$ japonica rice seeds, and the germinating ratio of japonica rice seeds was higher than that of I${\times}$J rice seeds in the water. DO requirements of germinating rice seeds in the water were average 82.4 ${\mu}$g per seed up to coleoptile appearance and average 123.6 ${\mu}$g per seed up to appearance of radicle in the japonica varieties, but I${\times}$J varieties were 96.9 ${\mu}$g and 145.1 ${\mu}$g respectively. Especially when the rice seeds were germinated in the water, length of coleoptile and radicle of japonica rice were significantly longer than those of I${\times}$J rice varieties.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.280-285
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• 1983

The effect of pH and calcium on the growth of subterraneum clover (Trifolium subteraneum L.) varieties Dwalganup, Mt. Barker, and Tallarook was determined in solution culture. At pH 4.5 and below all components of growth except germination percentage were adversely affected. The effect of lower pH was improved at high calcium level(3.0mM). There was a varietal difference in response to low pH. Mt. Barker showed the highest percent germination and produced the longest radicle length, whereas the greatest value in top dry weight, root dry weight, root length and number of laterals was obtained with Tallarook.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.776-782
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• 2016

Salinity has been a threat to agriculture in some parts of the world; and recently, the threat has grown. Plant growth-promoting rhizobacteria (PGPR) may benefit plant growth, either by improving plant nutrition or producing plant growth hormones. The effects of rhizobacterial strains to attenuate the salinity stress on the germination of Chinese cabbage seeds were tested using four different concentrations of NaCl (50, 100, 150, and 200 mM). Also, PGPR strains were tested to enhance the early germination of Chinese cabbage seeds under normal conditions. Azotobacter chroococcum performed best with enhancing the radicle length of 4.0, 1.2, and 1.0 times at treatments of 50, 100, and 150 mM of NaCl, respectively. Additionally, significant differences were found in plumule length, A. chroococcum and Lactobacillus sp. showed remarkable activation either in normal or under stress conditions. Co-inoculation by three rhizobacterial strains (LAPmix) indicated synergistic effect to enhance the early germination of the seeds. The results of this study are promising for application of rhizobacterial strains that possess plant growth promoting traits to enhance the plant tolerance against salinity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.138-142
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• 1999

An experiment was carried out to find out the changes in morphology, sugars, and $\alpha$-amylase activity during the priming of rice seeds (Oryza sativa L. cv. ＇Ilpumbyeo＇). For priming, seeds were soaked in -0.6 MPa PEG solution at 15$^{\circ}C$ for 4 days (properly primed) and at $25^{\circ}C$ for 4 and 10 days (over-primed) and dried at room temperature. The size of coleoptile and differentiated leaves of properly primed seeds were bigger and coleoptile was separated from the other part of embryo compared with non-primed and over-primed seeds. As priming of seeds advanced, compound starch grains in the endosperm disintegrated into tiny starch granules, and small holes were found in the tiny starch granules and a cavities developed between embryo and endosperm. The radicle and plumule of properly primed germinating seeds developed faster than non-primed and overprimed germinating seeds. Sucrose, maltose, and raffinose contents of properly primed seeds decreased, while content of glucose and fructose and $\alpha$-amylase activity increased. However, sugar content and $\alpha$-amylase activity of over-primed seeds were lower compared with non-primed seeds or properly primed seeds.

• Journal of Life Science
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• v.10 no.6
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• pp.598-604
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• 2000

This study was conducted to investigate the effect of simulated acid rain (SAR) on germination, growth, acid buffering capacity and nutrient leaching in Impatiens balsamina L. and Tagetes patula L.. In both species, germination was not inhibited at pH 4.0, but the germination rate decreased at the lower pH of 3.0, showing higher rate in Inpatiens balsamina L. than Tagetes patula L.. As the pH decreases, the growth of radicle was markedly decreased than that of hypocotyl in both species. The plant height, root length, leaf area, total dry weight, relative growth rate and net assimilation rate were inhibited by SAR. The acid buffering capacity in the leaves were increased at pH 4.0, on the other hand, it was shown a tendency to decrease at pH 2.0 in both species. As the pH levels decreased from 5.6 to 2.0, the nutrient leaching from leaves was significantly increased in both species. Based on the results, there are a great difference in the responses to SAR between the two species. In general, Tagetes patula L. represented a higher tolerance to SAR than Impatiens balsamina L.. These results suggested that interspecific variation in the acid buffering capacity and nutrient leaching from leaves may be responsible for the interspecific susceptibility to SAR.

• Journal of Plant Biology
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• v.28 no.4
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• pp.285-296
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• 1985

To examine the differentiation and transition of vascular system in Prunus davidiana FR., the mature embyro and developing seedlings were embedded in paraplast and treated by clearing method. In mature embryo, the procambium was connected with the epicotyl-hypocotyl-radicle axis and cotyledons, whereas protophloem and protoxylem were restricted primarily to the mid-vein and two lateral veins of the cotyledonary base. With the onset of germination, protophloem and protoxylem were differentiated both acropetally and basipetally from the cotyledonary base. The first and second leaf traces appeared in the cotyledonary node, and then differentiated bidirectionally toward the epicotyl and the root tip. The 3rd to 6th leaf traces were connected with the cotyledonary traces in hypocotyl. At the part of the root tip, the xylem was a diarch. As the first and second leaf traces were superimposed at the middle part of the root, the diarch xylem was changed to a tetrarch. As the cotyledonary traces were diverged below the root base, the tetrarch xylem was changed to an octarch. It was suggested that the vascular system of the epicotyl might be superimposed on that of the cotyledon-hypocotyl-root during the formation of the primary vascular system of Prunus davidiana.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.44-53
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• 2021

The present work aims to study the induction of somatic embryogenesis in cork oak (Quercus suber L.) from immature zygotic embryos and young apical leaves obtained from 2-month-old seedlings through acorn germination on sterilized peat. The immature zygotic embryos were grown for 1 month on the mineral solution of MS in the presence of 4.52 µM 2,4-D and 30 g/L sucrose. They were then transferred to the same mineral solution with no added growth regulators. In the third subculture, yellow somatic embryos, characterized by two voluminous cotyledons, were differentiated from the radicle of the immature zygotic embryos. The induction of somatic embryogenesis in young leaves required a series of transfers on different culture media containing 30 g/L sucrose and 100 mg/L myo-inositol. Secondary or recurrent somatic embryogenesis occurred within the immature somatic embryo radicles after 1 month of culture on growth regulator-free medium containing WPM macronutrients, MS micronutrients, and vitamins.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.160-166
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• 1997

Number of bacterial isolates were collected from high mountainous areas at various locations in the whole country to select promising biocontrol agents. Most of selected isolates belonged to fluorescent pseudomonads. Population densities of fluorescent pseudomonads were examined by DLF method. Alll selected isolates rapidly multiplied on spermosphere after seed inoculation upto 24, and then the population abruptly declined. When seeds were germinated fully, bacteria moved to newly emerging radicle. The good root colonizing isolates, B16 and V13 proliferated on the growing root and moved down to the root tip and lateral roots. but the poor root colonizing isolates, MC07 and X01 moved much slower. Scanning electron microscopic observations showed that the cells of the good colonizing isolates were arranged linearly on the growing root and parallel to growing root axis and continuously existed on the root tip, Whereas the cells of poorly colonizing isolates were gathered and scattered randomly on the root surface.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.211-215
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• 1977

The Sporulation of Didymella bryomiae were observed under diurnal cycles of light/darkness of near ultraviolet light (NUV) and artificial daylight (ADL) and continous darkness in eight isolates growing on PDA and V-8 juice agar. Light stimulated pycindial and perithecial formation of this fungus on potato dextrose agar and V-8 juice agar. Sprulation was poor in darkness, but some isolates were able to produce pycnidia and perithecia in the absence of light. Perithecial formation was much better under artificial daylight (ADL) on V-8 juice agar than those grown under near ultraviolet light (NUV). In general, cultures grown on V-8 juice agar sporulated better than cultures grown on PDA under three setsof light condition. Most of the pycnidiospores obtained from each isolates of this fungus grown on PDA were non-septate and microtype, but macrotype of non-septate and uniseptate pycnidiospores were produced on V-8 juice agar. Pycnidiospore produced on V-8 juice agar were similar to those produced on the radicle of naturally infected seeds. The appearance of perithecia were quite distinctive from pycnidia. The mature perithecia were darker than pycnidia and whitish spore masses formed on the ostiole of perithecia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.112-117
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• 2000

This study was conducted to evaluate the drought tolerance of Japonica and Indica rice cultivars during germinating and seedling stages by using the polyethylene glycol (PEG) solution. Each 5 cultivars of Japonica and Indica were cultured from 14 days after seeding(DAS) to 21 DAS using the PEG solution in a moderate water potential (-0.63 MPa). The lengths of radicle and plumule during the germinating stage were inhibitied by the PEG treatment to about 50% and 85%, respectively. The application of PEG to the seedling of two rice types caused to inhibit the plant height and leaf age about 23 % and 10%, respectively. Shoot and root dry weights by PEG treatment were inhibited more severely in Japonica than those in Indica. The difference on delaying of leaf area expansion between both rice types was not found with treatment of PEG, while the leaf color was increased in both Japonica and Indica by 19.9% and 9.2%, respectively. The average photosynthetic ability was inhibited more in Japonica to 36.0% than did Indica to 27.9%. The stomatal conductance was severely affected by PEG treatment, and the degree was varied in both rice types, ranged with 80-85% in Japonica and 29.3-81.6% in Indica. These results indicate there is little relationship between seed germination and seedling growth under the stress of low water potential.