• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.328-331
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• 2000

Maize (Zea mays L. cv. kosungjaerae and cv. youngwoljaerae) seeds were irradiated with the dose of $0.5{\sim}20$ Gy by $^{60}Co\;{\gamma}-ray$ radiation to investigate the effect of the low dose ${\gamma}-ray$ radiation on the germination rate, early growth and yield. The low dose radiation was able to improve the germination rate and early growth in maize, but the optimal radiation doses were different depended on kinds of cultivars. High stimulatory effect in early growth of maize was observed in 2 Gy irradiation group of kosungjaerae cultivar and in 12 Gy irradiation group of youngwoljaerae cultivar. The optimal radiation dose for the enhancement of yield and yield components in maize was 8 Gy in kosungjaerae cultivar and $4{\sim}12$ Gy in youngwoljaerae cultivar.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.43-47
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• 2004

This research was investigated to prepare basic data in a study on the copper tolerance of herbaceous plants through the growth rate and the elimination rate dependent on Cu concentration of 6 species; Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae, We examined the germination rate, root and shoot growth of seedling and fresh biomass of 6 species (Commelina communis, Medicago sativa, Echinochloa frumentancea, Zea mays, Helianthus annuus and Abutilon avicennae) painted to Cu contaminated soil (50, 100, 200, 300-CuCl₂/㎏) and control for 14 days. The germination rate of H. annuus, E. frumentancea and C. communis were not affected by Cu concentration. However, root and shoot growth of H. annuus was about 7% of control and the biomass was 35% of control at 300 ㎎-CuCl₂/㎏. E. frumentancea and C. communis that showed good growth rate at higher Cu contaminated soil (>200 -CuCl₂/㎏), were the most tolerant plant to Cu concentration. Especially, E. frumentancea eliminated over 30% of Cu in soil and the amount of Cu uptake increased with increasing Cu concentration; 1,020㎎ Cu per 1 ㎏ of soil at 300 ㎎-CuCl₂/㎏. From these results, we concluded that E. frumentancea would be used for phytoremediation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.10a
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• pp.27-27
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• 2017

• Proceedings of the Korean Society of Crop Science Conference
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• 1999.05a
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• pp.168-169
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• 1999

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.66-67
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• 1986

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.341-341
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• 2017

Abiotic stress adversely affects crop growth worldwide. Drought of the major abiotic stresses have the most significant impact on all of the crop. The main objective of this study was to assess the effects of drought stress on photochemical performance and vitality of maize (Zea mays L.). The photochemical characteristics were analyzed in the context of period of drought stress during the maize growth. Drought experiment was carried out for four weeks, thereafter, the drought treated maize was re-watered. The polyphasic OJIP fluorescence transient was used to evaluate the behavior of photosystem II (PSII) and photosystem I (PSI) during the entire experiment period. In drought stress, the performance Index (PI) level was reached earlier when compared to the controls. For the screening of drought stress tolerance the drought factor index (DFI) of each variety was calculated as follow DFI= log(A) + 2log(B). All the fourteen cultivars show DFI ranged from -0.69 to 0.30, meaning less useful in selection of drought tolerant cultivars. PI and electron transport flux values of fourteen cultivars were to indicate reduction of photosynthetic performance during the early vegetative stage under drought stress. In conclusion, DFI and energy flux parameters can be used as photochemical and physiological index.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.26-39
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• 2020

In maize, immature embryos (IEs) are highly regenerative explants most suitable for producing high frequencies of plantlet regeneration in vitro. Apart from media, explants, and hormones, genotypic variation also influences in vitro characters to a great extent. In the present study, IEs were used to study the distinctive effect of variation of size/stage and hormones in different genotypes on five in vitro characters viz., frequency of callus induction, growth rate of total callus, frequency of E. callus induction, and volume and number of regenerated plantlets. LS medium with different concentrations of 2,4-D (0.5, 1.5, 2.5, 4.0 and 5.0 mg/L) were used to study the former four in vitro characters, and medium with 6-benzylaminopurine and kinetin (0.5 mg/L, each) was used for plantlet regeneration. IEs of 1.0, 1.5, 2.0, 2.5 and 3.0 mm in size were isolated from four inbred lines viz., NM74C, NM81A, NM5883 and NM5884. Two-way ANOVA revealed that explant size and genotypes, as well as hormonal concentrations showed significant effects on in vitro characters. Two millimeter IEs were found to be suitable for in vitro cultures. LS medium with 1.5 mg/L 2,4-D and LS with BAP and Kn (0.5 mg/L, each) were found to be the best hormonal concentrations for callus induction, maintenance, and regeneration, respectively. Among the four genotypes, NM81A and NM5883 yielded more non-embryogenic and Type I E. calli. In contrast, NM74C and NM5884 yielded more highly regenerative Type II calli. Inbred line NM5884 was found to be the best among these four genotypes.

• Journal of Plant Biology
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• v.32 no.3
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• pp.137-144
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• 1989

In order to clarify the effect of the associative nitrogen fixing bacteria on the growth of corn(Zea mays L. Suwon19), we inoculated corn seedlings with Azospirillum amazonense Y1, a micro-aerobic and acid-tolerant nitrogen fixer, and analyzed the growth and dry matter production and changes of nitrogen and phosphorus quantity of the plant during the growing period. The inoculation of associative N-fixing bacgteria increased the growth of height, leaf area, dry weight and total nitrogen quantity of the plant by 15.4%, 65.4%, 33.7% and 38.0%, respectively, on the day of 56th after sowing. Especially the inoculation of A. amazonense Y1 showed two to three-fold accumulation of phosphorus in each organ of plant. The associative bacteria accelerated the growth of the under ground parts more than those of the upper ground parts of corn plant, and caused decrease in T/R ratios.

• Mycobiology
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• v.37 no.1
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• pp.72-76
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• 2009

To investigate the growth response of various crop species to mycorrhizal inoculation, arbuscular mycorrhizal fungi were applied to Glycine max, Vigna angularis, Senna tora, Hordeum vulgare var. hexastichon. Zea mays, Sorghum bicolor, Allium tuberosum, Solanum melongena, and Capsicum annuum. The biomass of the inoculated crops was measured every two weeks for the 12-week growth period. By measuring biomass, we calculated the mycorrhizal responsiveness of the nine crop species. Among the nine crop species, four species showed a significant response to mycorrhizal inoculation. The shoot biomasses of V. angularis, C. annuum, A. tuberosum, and S. tora significantly increased with mycorrhizal inoculation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.9-16
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• 2019

This study was carried out to investigate the effects of seeding dates and cultivated period on the growth characteristics, dry matter yield and feed value of Teosinte new variety "Geukdong 6"[Zea mays L. subsp. mexicana (Schrad.) H. H. Iltis]for feed. The experimental design was arranged in a randomized block design with three replications. Treatments consisted of five time seeding dates, 10 May(T1), 25 May(T2), 10 June(T3), 25 June(T4) and 10 July(T5), and same time harvesting, 22 October. Therefore, growing period were 164 days(T1), 149 days(T2), 134 days(T3), 119 days(T4) and 103 days(T5), respectively. In growth stage at harvest time, T1, T2, T3, T4 and T5 were early flowering, end heading, middle heading, early heading and early heading stage, respectively. Plant length and dead leaf were highest in T1, but leaf width and number of leaf were highest in T2 than others (p<0.05). Leaf length, stem diameter and number of tiller were not significantly different among the treatments (p<0.05). Stem hardness was higher in order of T1(2.0)> T2(1.9) > T3=T4(1.7) > T5($1.2kg/cm^2$). Fresh yield and dry matter yield showed significantly higher as the sowing time was faster and the cultivation period was longer (T1 > T2 > T3 > T4 > T5, p<0.05). Crude protein, crude fat and TDN content were highest in T5, but ADF and NDF content were highest in T1 than others (p<0.05). T1, T2 and T3 showed significantly higher crude protein yield compared to T4 and T5 (p<0.05). Total digestible nutrients yield were higher in order of T1 > T2 > T3 > T4 > T5 (p<0.05), and relative feed value were higher in order of T5 > T4 > T3 > T2 > T1 (p<0.05). Based on the above results, seeding dates could be recommended from the early May to the late May, and it is efficient that the cultivation period is over 150 days for dry matter yield, crude protein yield and total digestible nutrients yield.