• Journal of Environmental Science International
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• v.1 no.1
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• pp.13-21
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• 1992

The inhibitory effects of mercury ions on the growth of barley seedlings were studied and the distribution of metal elements in the organs of treated plants was investigated by using synchrotron radiation induced X-ray emission (SRIXE). Although the treatment of mercury ions caused growth inhibition, the mercury-specific increase in variable fluorescence and the abolishment of energy-dependent quenching in broken barley chloroplasts as shown by Moon et at. (1992) were not observed in the leaves of growth-inhibited seedlings. Instead the treatment of mercury decreased Fmax and Fo values. However, Fmax/Fo ratio and photochemical and nonphotochemical quenching coefficients were not affected significantly. By SRIXE analysis of $10\mu\textrm{m}$ mercury chloride treated seedlings, accumulation of mercury in roots was observed after 1 hour of treatment and similar concentration was sustained for 48 hours. Relative contents of mercury was high in roots and underground nodes where seeds were attachedl but was very low in leaves. Iron and zinc were also distributed mainly in the lower parts of the seedlings. However after 72 hours of treatment the contents of these metals in roots decreased and their distribution became more uniform, which may lead to death of the plants. These results suggest that the observed inhibitory effects on barley seedlings upto 48 hours after the treatment is not due to direct damages in the photosynthetic apparatus, but due to its accumulation in roots and the consequent retardation of the growth of barley seedlings. The decrease in Fmax and Fo is probably due to the decrease in chlorophyll and protein contents caused by the retardation of growth. The observed slow expansion of primary leaves could be also explained by the retardation of growth, but the fluorescence induction pattern from the leaves did not show characteristic symptoms of leaves under water stress.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.97-102
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• 1995

The purpose of this study was to investigate the effect of artificial acid rain(pH2.0, 3.0. 4.0 and 5.0) adjusted by natural rain fall and control group by pH6.5 on the change in needle chlorophyll fluorescence of Pinus densiflora and Pinus thunbergii. This study was performed from May, 1994 to August, 1994, during which 20ml of artificial acid rain was used once a week. The results are as follows : In the first treatment of artificial acid rain the measured indexes of fluorescence have increased in pH4.0 and pH5.0 treatments and decreased in pH2.0 and pH3.0 in comparison with those of the control group. As the treatment of artificial acid rain was processed the fluorescence indexes of both Pinus densiflora and Pinus thunbergii have decreased as the degree of acidity increased higher and that of Pinus densiflora has decreased more significantly than Pinus thunbergii. The measurement of change in the numerical indexes of fluorescence was proved to be a very effective criterion to make an early decision of damage of the vegetation by acid rain.