• The Korean Journal of Mycology
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• v.21 no.4
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• pp.316-322
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• 1993

Examination by scanning electron microscopy and potato-dextrose agar medium showed that the dry seeds of R. raetam were externally free of fungi. When planted in sandy loam soil, the seeds become colonized with eleven soilborne fungal species. The fungi were isolated on cellulose agar, pectin agar and lignin agar media. Aspergillus flavus, A. niger, Penicillium capsulatum and Fusarium oxysporum had broad occurrence and recovered on the three media. The production of hydrolytic enzymes by the isolated fungi depends on the substrate and species. P. capsulatum, P. spinulosum and A. niger had wide enzymatic amplitude and they were able to produce cellulolytic, pectolytic and lignolytic activities on corresponding substrates as well as on seed coat containing media. The lignolytic activities of the isolated species except Chaetomium bostrychods and Trichoderma viride were enhanced on applying the seed coat materials as C-source rather than using lignin. Soaking R. raetam seeds in culture filtrates of the most fungi grown on seed coat supplemented media induced pronounced and distinct stimulating effect on seed germination. The most effective filtrates were those of P. capsulatum, P. spinulosum and Sporotrichum pulverulentum.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.586-593
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• 2007

Seed coating by a phenazine-producing bacterium, Pseudomonas chlororaphis O6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. In wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. Deletion of the gacS gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzI gene and the biosynthetic phzA gene. The inhibition of seed germination and the induction of systemic disease resistance against a bacterial soft-rot pathogen, Erwinia carotovora subsp. carotovora, were impaired in the gacS and phzA mutants of P chlororaphis O6. Culture filtrates of the gacS and phzA mutants of P. chlororaphis O6 did not inhibit seed germination of wheat, whereas that of the wild-type was inhibitory. Our results showed that the production of phenazines by P. chlororaphis O6 was correlated with reduced germination of barley and wheat seeds, and the level of systemic resistance in tobacco against E. carotovora.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.403-411
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• 2009

We inspected seed sizes of 353 genetic accessions of watermelon to diversify functional utility related to seed size and classified them into six representative groups based on their seed sizes. Each group was named as giant seed (GS), big seed (BS), medium size (NS), small size (SS), micro seed (MS) and tomato seed (TS) from the biggest. As the seed size was getting smaller, decreased seed length and seed width, increased seed number per fruit, and decreased seed weight per fruit were observed, but seed shape did not change significantly. In order to study the effect of seed size on fruit weight and seed germination, we developed three near isogenic lines (NILs) with three different seed sizes, SS, MS and TS, from crossing between two accessions 'NT' and 'TDR', and one NIL with seed size of TS from crossing between two accessions 'S55' and 'TDR'. In the study on the fruit weight of NILs with various seed sizes, NS, SS, MS, and TS NILs produced an average of 6.4, 6.3, 5.9, and 4.2 kg fruits, respectively. The bigger seed types showed the better germination rate. NS type showed the highest germination percentage, while TS showed very low germination percentage. Fermentation treatment for 48 hrs increased the germination percentage on TS type seed, but still remained at a low level. In NS, SS, and MS material, the ratio of embryo/whole seed weight was over 50%, meanwhile that of TS was only 44.4% of which low embryo percentage would be one of the reason of low germination percentage. From this study, we concluded that watermelon has very wide genetic diversity on seed size which is somehow related to fruit sizes and germination rate.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.53-57
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• 1999

The experiments were conducted to determine the factors such as light and darkness, phytohormone and seed coat, influencing on seed germination of Bidens tripartita L. and B. frondosa. The seeds of both species were germinated when seed coat was damaged and weakened. $GA_3$ and BA stimulated germination of both species but ABA and IAA had no effect on germination of them, which ranged 50.0% to 80.0%. In B. forndosa, when inner layer of seed coat was removed, germination was highly promoted up to 96.7% compared with 10.0% germination rate in another treatments.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.242-248
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• 1983

The effects of light source, plant growth regulators (GA, BA, ABA), and sodium hypochlorite (4% Cl, SH) on germination of 'G rand Rapid' lettuce (Lactuca sativa L.) seed were studied. Seed did not germinate under the conditions of dark and blue light. The treatment of GA or BA did not promote on germination under dark or blue light. The germination percentage under red light was very high, it was similar to the condition of white light. ABA inhibited lettuce seed germination. Although ABA was treated, BA 10ppm treatment was moderately effective under white light condition and BA 10ppm or 50ppm combined with GA 50ppm were also effective on seed germination under dark condition. Presoaking in sodium hypochlorite solution induced germination of lettuce seed in any condition of dark or white light. The optimum presoaking time in sodium hypochlorite solution was twenty min.

• Plant Resources
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• v.3 no.1
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• pp.66-70
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• 2000

Umbelliferae medicinal crops have low germination under natural condition. Special objective of this study is to investigate morphological characteristics of seeds and effects of environmental factors such as light and temperature on their germination and seedling growth in Umbelliferae plants, using them as oriental medicine materials. Fruits of Umbelliferae are bi-partite type and form 2 seeds. Their oil canals and funiculus or carpaphore has apparently specific shape. Seed shape of Buplerum falcatum, Ligusticum acutilobum and Foeniculum vulgare are oblong, Ledeboutiella seseloides, Angelica dahurica, Angelica gigas elliptic, and Ostericum koreanum ovate. Color of seed coats varied from yellow to dark brown. Seed size was 3.2 to 6.9 mm in length, 1.7 to 4.9 mm in width. One thousand-seed weight of Buplerum falcatum was lowest(at 1,660 mg) and Ledebouriella seseloides and Angelica gigas were relatively highest(at 3,970 mg) having larger size than any others. Optimum temperatures for seed germination and seedling growth ranged from 20 to $25^{\circ}C$ and especially temperature at $25^{\circ}C$ improved seed germinations of Ledebouriella seseloides, Angelica dahurica and Ligusticum acutilobum regardless of light condition.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.303-306
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• 2006

Seed of Codonopsis lanceolata exhibits low germination due to impermeable seed coat. Prolonged seed dormancy can be overcome by the application of gibberellins, as it promotes growth of the embryo and weakens the structures surrounding of embryo. The effects of photoperiod, sugar and gibberellin concentration were investigated at constant temperature for 12 days and 22 days in vitro and invivo conditions respectively. The rate of germination of seeds of Codonopsis lanceolata in wet filter paper in both complete dark and light treatments was significantly lower than that of seed treated with $GA_3$. It clearly indicates that there is significant coat imposed dormancy in the seed of Codonopsis lanceolata. The rate of germination in vivo condition was lower than that of the in vitro condition supplemented with $GA_3$ Thus, the physical dormancy due to impermeable seed coat and low level of endogenous gibberellins in the seed was the cause of poor germination rate in Codonopsis lanceolata.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.618-624
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• 2010

This study was conducted to establish the in vitro seed germination of Loranthus tanakae. A factorial experiment evaluated the effects of seed storage duration (0, 8, 16 weeks), media (MS, SH, White, WPM), presence of viscin, GA3, gelling agent and concentrations. Seed germinated after one week culture in in vitro condition and produced radicles. In vitro seed germination was optimal when the seeds removed viscin placed on SH medium (69%) and the addition of 0.35% gelrite (75%) in the same medium. As seed storage duration was expanded to 8 or 16 weeks, in vitro seed germination rate was reduced rapidly. Holdfasts were also produced at the side of radicles. The important factors to produce holdfast and haustorium was kind of media as an optimal condition in White medium without any supplements to be shown 98% and 8% respectively. Process of in vitro germination of Loranthus tanakae was followed to radicle elongation, holdfast development and then haustorium formation sequencially.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.154-154
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• 2017

Root is an important organ of plant that typically lies below the surface of the soil. Root surface determines the ability of plants to absorb nutrient and water from the surrounding soil. This study describes an application of image processing and computer vision which was implemented for rapid measurement of seed germination such as root length, surface area, average diameter, branching points of roots. A CCD camera was used to obtain RGB image of seed germination which have been planted by wet paper in a humidity chamber. Temperature was controlled at approximately 250C and 90% relative humidity. Pre-processing techniques such as color space, binarized image by customized threshold, removal noise, dilation, skeleton method were applied to the obtained images for root segmentation. The various morphological parameters of roots were estimated from a root skeleton image with the accuracy of 95% and the speed of within 10 seconds. These results demonstrated the high potential of computer vision technique for the measurement of seed germination.

• Molecules and Cells
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• v.19 no.3
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• pp.334-341
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• 2005

Plants are sessile and rely on a wide variety of growth hormones to adjust growth and development in response to internal and external stimuli. We have identified a gene, designated NAN, encoding a basic helix-loop-helix (bHLH) transcription factor that regulates cell elongation and seed germination in plants. NAN has an HLH motif in its C-terminal region but does not have any other discernible homologies to bHLH proteins. A bipartite nuclear localization signal is located close to the HLH motif. An Arabidopsis mutant, nan-1D, in which NAN is activated by the insertion of the 35S enhancer, exhibits growth retardation with short hypocotyls and curled leaves. It is also characterized by reduced seed germination and apical hook formation, symptomatic of GA deficiency or disrupted GA signaling. The phenotypic effects of nan-1D were increased by treatment with paclobutrazol (PAC), an inhibitor of gibberellic acid (GA) biosynthesis. NAN is constitutively expressed throughout the life cycle. Our observations indicate that NAN has a housekeeping role in plant growth and development, particularly in seed germination and cell elongation, and that it may modulate GA signaling.