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  • Author or Editor: Dong-Chun Shin x
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Pimpinella brachicarpa (Chamnamul in Korean) is an indigenous plant that grows in Korean mountain areas. It has not been cultivated yet but is gathered to use as a vegetable. Its difficulty of propagation by seeds is one of the major reasons not to be cultivated as a horticultural crop despite its demand. As a promising propagation method for the Chamnamul, we have developed a micropropagation system using somatic embryogenesis. In the present study, induction of embryogenic callus of the Chamnamul affected by part of explants (leaf and stem) and concentration (0, 0.1, 0.5, 1.0, 1.5, and 2.0 mg·L-1) of growth regulators (2.4-D, IAA, IBA, and NAA) was investigated to find the best conditions for embryogenic callus induction. A full strength of MS medium was used for a 50-day culture for all the treatments. The embryogenic callus was firm and light yellow in color and was distinct from the non-embryogenic callus that was friable and semitransparent. More embryogenic callus was induced in the treatments that the stem was used as an explant comparing with the treatments that the leaf was used. The 2.4-D treatments resulted in the better induction of embryogenic callus than other growth regulator treatments, and 1.5 mg·L-1 was the most effective among all the 2,4-D concentration treatments. Addition of 0.1 mg·L-1 BA to 2.4-D treatments retarded the induction of embryogenic callus of the Chamnamul, while the promotion of induction and multiplication of embryogenic callus was reported in many plant species by adding BA with low concentration to an auxin-base medium. The better induction was found in the treatments of darkness and dim lighting (10 μmol·m-2·s-1 of PPF) than in treatments of the higher PPF.

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A cohort of sixth grade students at two newly constructed elementary schools in Seoul, South Korea, performed a self-assessment of ocular discomfort symptoms in association with indoor air quality (IAQ) by indoor plant intervention from early June to mid-Oct. 2011. Indoor plant intervention made little difference in air temperature and relative humidity, but stabilized the increasing levels of carbon dioxide. The indoor concentrations of formaldehyde and ethylbenzene showed little difference, but those of toluene and xylene showed a decreasing trend in classrooms with indoor plants. The participants in classrooms without indoor plants exhibited an increase in ocular discomfort symptoms at School A and a decrease in symptoms at School B; those in classrooms with indoor plants demonstrated a decrease in frequency at both schools. The variation of symptom severity did not follow a clear trend. Participants assessed their symptom severity of ocular discomfort with four options from three points for frequent occurrence to zero points for no occurrence. Among participants in classrooms without indoor plants, symptom severity significantly worsened at both schools as the scores increased from 1.96 to 2.17 at School A and from 2.27 to 2.34 at School B; among those in classrooms with indoor plants, symptom severity significantly lessened at School A and slightly worsened at School B as the scores decreased from 2.33 to 1.98 at School A and increased from 2.35 to 2.42 at School B. After spending the experimental duration in classrooms without indoor plants at both schools, 34.8% of participants at School A and 33.3% of participants at School B perceived their symptom severity as having increased. At Schools A and B, indoor plants decreased the frequency of participants experiencing an increase of symptom severity by 13.0% and 9.7%, and increased the frequency of participants reporting decrease of symptom severity by 34.8% and 22.6%.

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