• Plant Breeding and Biotechnology
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• v.5 no.3
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• pp.204-212
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• 2017

There is a growing preference for using doubled haploids (DHs) in maize breeding programs because they reduce the time required to generate and evaluate new lines to 2 years or less. However, there is an urgent need for efficient techniques that accurately discriminate between haploid and diploid maize kernels. Here, we investigate the effects of several hormones and chemicals on the germination of haploid and diploid maize kernels, including auxin, cytokinin, ethylene, abscisic acid (ABA) biosynthesis inhibitor (fluridone), ABA catabolism inhibitor (diniconazole), methyl jasmonate (MeJA), and NaCl. Ethylene effectively stimulated the germination of both haploid and diploid maize kernels. The ABA biosynthesis inhibitor fluridone, the ABA catabolism inhibitor diniconazole, and MeJA selectively stimulated the germination of haploid maize kernels. By contrast, gibberellin, 1-naphthaleneacetic acid (NAA), kinetin, and NaCl inhibited the germination of both haploid and diploid maize kernels. These results indicate that the germination of haploid maize kernels is selectively stimulated by fluridone and diniconazole, and suggest that ABA-mediated germination of haploid maize kernels differs from that of diploid maize kernels and other plant seeds.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.182-187
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• 1977

This investigation was to determine the changes in the trypsin inhibitor activity(TIA) and electrophoresis patterns of the soybean cotyledon and axis during germination. The TIA of the cotyledon decreased slightly and that of the axis decreased rapidly to 50% activivity after 7 day germination. At the 2nd, 3rd and 4th day's germination the TIA of the defatted dry axis was higher than that of cotyledon. However, the TIA of the fresh cotyledon was lower than that of the axis, due to its higher moisture content. Results from the electrophoretic studies showed that band 1 (polymer, 15S etc.), 2(11S), and 3(7S) whichare the major reserve proteins of soybean were decreased consid erably in cotyledon and axis and the fragments with Rm values between 0.5 and 1.0 were increased and band 5 showed up during germination. The band 4 of the cotyledon and band 6 of axis were not changed during germination. Generally speaking, the TIA and thereserve protein decreased as germination proceed.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.61-67
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• 1984

Conidial germination of Septoria glycines Hemmi, brown spot fungus of soybean, was studied by slide germination test. Poor conidial germination of S. glycines was observed on sterile distilled water, but potato dextrose agar(PDA) and distilled water floated with soybean leaf disc furnished a satisfactory medium for conidial germination. Exogenous supply of carbon source was essential for conidial germination, while phosphorous and potassium were not evident as that for carbon. Soluble starch was the most suitable as a carbon source for conidial germination and followed by D-glucose, D-galactose and lactose in that order. Maximum germination was attained in the $5\times10^{-2}mol$. concentration of glucose. Germination was decreased with increment of conidial concentration and was almost completely suppressed in the density of 10,000 conidia per $mm^2$. It suggested existing a self-inhibitor(s). Non-washed conidia germinated more than washed conidia and this was obvious when the conidia density was over $2\times10^3$ conidia per $mm^2$ on the dry agar block.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.219-232
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• 2019

Chemicals related to hydrogen peroxide ($H_2O_2$) and nitric oxide (NO) generations were exogenously applied to Fusarium oxysporum f. sp. fragariae (Fof) causing Fusarium wilt disease in strawberry plants, and regulations of in vitro conidial germination and mycelial growth of the fungus by the chemical treatments were evaluated. $H_2O_2$ drastically reduced the conidial germination of Fof in a dose-dependent manner, and treatment with 3-amino-1,2,4-triazole (3-AT) catalase inhibitor also led to dose-dependent inhibition of conidial germination but relatively moderately. Gradual decreases in mycelial growth of Fof were found by high concentrations of $H_2O_2$, whilst exogenous 3-AT slightly increased the mycelial growth. Increasing sodium nitroprusside (SNP) NO donor, $N^G$-nitro-l-arginine methyl ester (L-NAME) NO synthase (NOS)-inhibitor and tungstate nitrate reductase (NR) inhibitor led to dose-dependent reductions in conidial germination of Fof in quite different levels. SNP conversely increased the mycelial growth but increasing L-NAME moderately decreased the mycelial growth. Tungstate strongly enhanced mycelial growth. Differentially regulated in vitro mycelial growths of Fof were demonstrated by SNP, L-NAME and tungstate with or without $H_2O_2$ supplement. Superoxide anion production was also regulated during the mycelial growth of Fof by nitric oxide. These results show that $H_2O_2$ and NO-associated enzymes can be suggested as fungal growth regulators of Fof as well as eco-friendly disease-managing agents in strawberry production fields.

• The Korean Journal of Ecology
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• v.14 no.2
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• pp.121-135
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• 1991

A number of laboratory experimentes have performed to elucidate water-soluble of volatile substances from wormwood plant(artemisia princeps var. orientalis) as growth inhibitor or phytotoxicant. in germination tests with aqueous extracts of leaves, stems and roots of the wormwood plants, most tested species showed that relative germination ratio was inversely proportional to comcentration of the extracats. and seedling elongation and dry weight of the species were heavily inhibited with the extracts, incubated leaves, volatile substances of the leaves and soil underneath wormwood plants. gas Chromatography was employed to find out possible phytotoxic substances or growth inhibitors of wormwood leaves. ten substantes have isolated, and most of them were identified as terpenoids.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.225-231
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• 2011

Previously, we identified the 20S proteasome ${\alpha}$-subunit of Magnaporthe oryzae (M. oryzae) induced during appressorium formation, and detected an increase in multiple protein ubiquitination during the early appressorium formation process (Kim et al., 2004). In this study, we further attempted to determine whether the proteasome is involved in the appressorium formation of M. oryzae both in vitro and in planta, using proteasome inhibitors. A significant increase in 20S proteasome during fungal germination and appressorium formation was observed using Western blot analysis with 20S proteasome antibody, demonstrating that proteasome-mediated protein degradation was involved in appressorium formation. Pharmacological analysis using proteasome inhibitors, MG-132, proteasome inhibitor I (PI) and proteasome inhibitor II (PII) revealed that germination and appressorium formation were delayed for 4 to 6 h on rice leaf wax-coated plates. Similarly, the treatment of proteasome inhibitors with fungal conidia on the rice leaf surface delayed appressorium formation and host infection processes as well. Additionally, fungal pathogenicity was strongly reduced at 4 days' postfungal infection. These data indicated that the fungal 20S proteasome might be involved in the pathogenicity of M. oryzae by the suppression of germination and appressorium formation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.287-294
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• 2006

Germination and early elongation of rice after germination were investigated in anoxic air treatment, nitric oxide gas treatment, and six concentrations of mercuric chloride solutions to determine the effects of limited oxygen environment, nitric oxide, and inhibited water flux through cell membrane in $17^{\circ}C$. Anoxic air treatment affected germination of tested six varieties very little. However root elongation rates were severely inhibited while shoot growth was affected less. Reductions in shoot and root elongations demonstrated genotypic variations. Nitric oxide delayed the germination of rice even though it didn't affect the final percent germination. Elongations of root and shoot were inhibited in nitric oxide treatment. The inhibitor effect of nitric oxide on the shoot elongation of rice was less severe, while nitric oxide completely inhibited the root emergence of rice. Concentrations of $HgCl_2$ greater than $300{\mu}M$ dramatically reduced the rate and percentage of germination when compared to distilled water treatment. The reduced percent germination showed the greatest variation among rice varieties in $500{\mu}M$ solution of mercuric chloride. Ansanbyeo, Jinheung, and Odaebyeo were affected less by $HgCl_2$, Nonganbyeo and Sangmibyeo were intermediate, and the germination of Andabyeo was greatly reduced by $HgCl_2$. Root elongation of germinated rice seedlings was more sensitive to oxygen deficits, nitric oxide, and $HgCl_2$ treatments than germination and shoot elongation. In conclusion, poor seedling establishment of rice sown in flooded paddy soils, in which the oxygen supply to the seeds is restricted, appears to the result of limited root elongation rate.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.279-282
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• 2002

Oryzalexine A, a potent growth inhibitor against several weeds such as Digitaria sanguinalis (L) Scop., and Amaranthus lividus L. was purified by conventional solvent partitioning and column chromatographies. This substance showed strong inhibitory activity on several weeds: Germination of seeds of Poa annua L. was inhibited by 36.5 % at 1.0 mM and Amaranthus lividus L. by 56.1% at 2.5mM. Growth of root and shoot of Digitaria sanguinalis (L.) Scop. by 10.2% and 22.4% at 2.5mM, respectively. These suggest that Oryzalexine A in rice straw might affect the germination and growth of susceptible weeds and other plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.384-394
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• 1996

The experiment was conducted to determine the seed characteristics and preferable methods to enhance the seed germination rate in Bupleurum falcatum. The optimum temperature for the seed germination of Bupleurum falcatum is 2$0^{\circ}C$. Any significant promoting effects were not found in seed germination with hormone treatments and physical methods. At 15$^{\circ}C$, prechilling combined with 50~200ppm of GA$_3$ treatment raised germination rate by 2 times of control ones. The most positive effect was observed in the treatment of 10$^{-2}$ ~10$^{-3}$ M potassium nitrate only at 15$^{\circ}C$ for 12 and 24 hours. The leachate of Bupleurum falcatum didn't inhibit the germination of Lactuca sativa, showing almost 100% of germination rate, which is suggested that no inhibitors contained in the seeds of Bupleurum falcatum. Observation of embryo conditions under stereoscopic microscope showed that the ratio of seeds with or without embryo is almost 50/50. The results suggested that the lower rate of germination in Bupleurum falcatum was caused by embryolessness of seeds.