• Journal of Life Science
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• v.12 no.1
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• pp.27-32
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• 2002

Enzyme electrophoresis was used to estimate genetic diversity and population structure of maize, Zea mays L. (Graminales) in Korea. In nine populations, fourteen of the 24 loci (58.3 %) showed detectable polymorphism. Genetic diversity (0.205) was higher than average values for species with similar life history traits. Although our data are relatively small and the landraces not direct ancestors of cultivar, apparently the domestication process has eroded the levels of genetic variation of maize. The recent cultivars were found to have fewer alleles per locus (1.42 vs. 1.56), fewer alleles per polymorphic locus (2.27 vs. 2.33), lower percent polymorphic locus (33.3% vs. 41.7%), and lower diversity (0.159 vs. 0.185) than landraces. These genetic diversity parameters indicated that the cultivar populations were genetically depauperate relative to landlaces. The GST value of nine populations was 0.239. Nearly 76% of the total genetic diversity in Zea mays was apportioned within populations. The indirect estimate of gene new based on mean GST was moderate (Nm=0.80).

• Journal of Life Science
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• v.16 no.5
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• pp.859-865
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• 2006

When thin slits (e.g., $1mm{\times}10mm$) of maize (Zea mays) coleoptiles were floated on a buffer, they spontaneously curved outward because of unbalanced tissue tension between inner and outer faces. Exogenously applied auxin induced inward curvature of the thin strip of the maize coleoptile in a dose-dependent manner. This bioassay system was used to screen endogenous substances that work together with auxin. In methanol extract of maize coleoptiles including the leaves inside, Active fractions that promote the auxin-induced inward curvature of maize coleoptile slices were found. The curvature-enhancing activity of the extract was not related to energy supply. The active substances were adsorbed to $C_{18}$ cartridges even at pH 10 and eluted in two fractions by 50% and 80% methanol. These substances were named as Curvature-Enhancing Factor-1 (CEF-1) and Curvature-Enhancing Factor-2 (CEF-2), respectively. The CEF-2 was resolved on a reversed phase $C_{18}$ column by HPLC.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.128-133
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• 1998

Analyses of now karyotypes using different maize (Zea mays L.) inbred lines have been performed. The accumulation and isolation of high quality and quantity metaphase chromosomes from root tips can be achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed with a now cytometry. The variations of experimental now karyotypes were detected among inbred lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among 8 inbred lines ranged from 5.09 to 5.52 pg. The variability of DNA content in maize chromosome 1 was 9.1 % ranging from 0.685 to 0.747 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines.

• Proceedings of the Botanical Society of Korea Conference
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• 2001.04a
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• pp.12-12
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• 2001

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1172-1175
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• 2007

We observed that exogenously applied ethanol changed the activities of aldehyde oxidases (AO) in the primary roots of maize (Zea mays). The stimulatory effect of ethanol on the aldehyde oxidase activities was concentration dependent; the AO activities were slightly weaker with 0.2 - 0.4% ethanol and stronger with 0.8 - 1.0% ethanol than the level of control. The promotion of AO activities was not explained by the increased transcription of two AO genes in maize. In contrast, ethanol strongly increased the amount of AO proteins, indicating that ethanol enhanced AO activities by promoting the translation. Among three alcohols including ethanol, methanol and isopropanol, only ethanol promoted AO activities. These results suggested that enhancement of AO activities was specific to ethanol, whose level could be naturally increased when the plant roots drove fermentation to overcome low oxygen stresses.

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.236.2-236
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• 1994

No Abstract, See Full Text

• Journal of Life Science
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• v.18 no.8
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• pp.1164-1168
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• 2008

We investigated gravitropic responses in the primary root of maize (Zea mays) seedlings which were exposed to salt stress. The maize roots salt-stressed with higher than 100 mM NaCl or KCl started to reveal enhanced gravitropic curvature after 2 hours form the gravi-stimulation. Such a promotion was not caused by sodium phosphate, but invoked by potassium phosphate, indicating the active component is $K^{+}$. Because NaCl increased gravitropic curvature, despite that $Na^{+}$ did not played any role, we evaluated the role for $Cl^{-}$ by comparing the effects of $MgCl_2$ and $MgSO_4$. The enhancement of the curvature only with $MgCl_2$ revealed that $Cl^{-}$ played a role in the gravi-response, indicating the involvement of anion channels. These results suggest that both of $K^{+}$ and $Cl^{-}$ play roles in the regulation of osmosis that is required for cell expansion in gravitropism as well as in nyctinasty and stomatal opening.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.483-486
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• 2000

The influence of feed allowance on intake and nutrient utilization by Barbari goats given green maize (Zea mays) and potential feeding value of left-overs were studied. The goats were offered food at 3 levels to give left-overs of about 20% (T-1), 35% (T-2) and 50% (T-3) DM of offered amount. A marked effect of refusal rate on intake and digestibility of nutrients was found. The DMI, g/kg $W^{0.75}$ increased from 39.86 in T-1 to 50.91 and 66.55 g in groups T-2 and T-3, respectively. Allowing selective consumption at higher levels (T-2 and T-3), the intake of TDN and DCP from green maize was found not only to meet the maintenance requirement but provided surplus energy and protein for substantial production. The variability in diet selectivity between goats under different treatments was pronounced. As the level of food excess increased to T-3, the left overs had a higher IVDMD and crude protein and decreased cell wall constituents (p<0.05). Considering the substantial increase in intake and digestibility from feeding green maize at high allowances to goats, further studies are needed to develop practical feeding strategies.

• Plant Resources
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• v.1 no.1
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• pp.33-37
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• 1998

Carotenoid compounds in embryos of wild-type(WT) and viviparous mutants of maize(Zea mays L.) were analyzed using high performance liquid ehromatography (HPLC) with a photodiode array detector. Zeaxanthin accumulates in WT embryos as the major carotenoid. Phytoene accumulates in vp2 and vp5. Phytofluene in w3 and ${\xi}$-carotene in the vp9 mutant embryos. This indicates that the vp2 and vp5 mutants impair phytoene desaturase from 15-cis-phytoene to 15-cis-phytofluene. The w3 mutant has neither an isomerase from 15-cis-phytofluene to all-trans-phytofuene nor phytofluene desaturase from phytofluene to ${\xi}$-carotene. The vp9 mutant does not have the ${\xi}$-carotene desaturase from ${\xi}$-carotene to lycopene. Our analysis shows that the terminal carotenoid. ${\gamma}$-carotene(${\beta},{\Psi}$-carotene), accumulates in the vp7 mutant embryos. The ${\varepsilon}$-carotene(${\varepsilon},{\varepsilon}$-carotene), a product of ${\delta}$-carotene(${\varepsilon},{\Psi}$-carotene) in some plants, however, has not been found in maize embryos. The vp7 mutant impairs a cyclization step from ${\gamma}$-carotene to both ${\beta}$-carotene and ${\alpha}$-carotene. We suggest that monocyclic ${\gamma}$-carotene is the sole precursor of both bicyclic ${\beta}$-carotene(${\beta},{\beta}$-carotene) and ${\alpha}$-carotene(${\beta},{\varepsilon}$-carotene) in maize.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.581-585
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• 1999

The antioxidative activity measured by electron donating ability was investigated for the breeding of the highest antioxidative waxy corn (Zea mays L.) and the research for the most effective antioxidant in waxy corn. The electron donating ability was $15.5{\sim}65.0%$. The contents of phenolic compounds and tocopherols and the absorbance at 450 nm were $102.3{\sim}323.5\;{\mu}g/mL$, $15.6{\sim}144.2\;{\mu}g/mL$ and $0.047{\sim}0.206$, respectively. The mean values of electron donating ability and contents of phenolic compounds and tocopherols of four black waxy corn were comparatively high, that is, 48.7%, $267.0\;{\mu}g/mL$ and $87.0\;{\mu}g/mL$, respectively. The electron donating ability was significantly correlated with the level of phenolic compounds and tocopherols but not with the content of carotenoids.