• Journal of Ginseng Research
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• v.33 no.1
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• pp.65-71
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• 2009

This experiment was done to determine the optimum conditions for the induction of tetraploidy in Panax ginseng C. A. Meyer using bud length, temperature and plant growth regulator pretreatments. Highest callus formation was obtained when the medium was inoculated with flower bud in the size of 2-3 mm in length. The optimum temperature for the callus formation was high when treated at $4^{\circ}C$ for 4-5 days. Among the treatments of growth regulators and different concentration, highest callus formation was observed in combination of 5 mg/L 2,4-D and 1 mg/L kinetin for P. ginseng. As a result of flow cytometer analysis, all 7 adventitious roots were confirmed as tetraploidys. Cytological analysis revealed that the chromosome number of tetraploid roots was 96, while that of diploid roots was 48. Tetraploid ginseng roots were inoculated to flower bud size of 2-3 mm in length. The callus formation was optimum when treated with 1 mg/L 2,4-D at $4^{\circ}C$ for 5 days. Compared with control roots, tetraploid roots were thicker and longer and had few lateral branches. Fresh weight of tetraploid roots was relatively higher than the control roots.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.223-225
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• 2007

Many plant growth-promoting rhizobacteria (PGPRs) have been known for beneficial effects on plants including biological control of soilborne pathogens, induced systemic resistance to plant pathogens, phytohormone production, and improvement of nutrient and water uptake of plants. We developed a simple and rapid method for screening potential PGPR, especially phytohormone producing rhizobacteria, or for analyzing their functions in plant growth using cucumber seedling cuttings. Surface-sterilized cucumber seeds were grown in a plastic pot containing steamed vermiculite. After 7 days of cultivation, the upper part 2 cm in length of cucumber seedling, was cut and used as cucumber cuttings. The base of cutting stem was then dipped in a microcentrifuge tube containing 1.5ml of a bacterial suspension and incubated at $25^{\circ}C$ with a fluorescent light for 10 days. Number and length of developed adventitious roots from cucumber cuttings were examined. The seedling cuttings showed various responses to the isolates tested. Some isolates resulted in withering at the day of examination or in reduced number of roots developed. Several isolates stimulated initial development of adventitious roots showing more adventitious root hair number than that of untreated cuttings, while some isolate had more adventitious root hair number and longer adventitious roots than that of untreated control. Similar results were obtained from the trial with rose cuttings. Our results suggest that this bioassay method may provide a useful way for differentiating PGPR's functions involved in the development of root system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.176-179
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• 2001

To obtain the basic information of high yielding ability for varietal improvement and cultural practice, reciprocal grafts were made analyzed among five sweet potato cultivars. Five cultivars were characterized with the different in whose source and sink capacities. Grafting decreased main vine length, number of tuberous roots per plant, but its effects were different among grafting combinations. The growth of vines was affected more by scion, while growth and yield of under-ground were influenced more by stock. Grafting effects, interactions between stock and scion for main vine length and number of tuberous roots were highly significant in diallel grafting. The percentage of marketable tuberous roots was higher in the order of stem cutting＞self grafting＞reciprocal grafting.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.231-235
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• 2009

Viral infections and root growth were examined to elucidate the relationship between viral resistance and root growth in 26 Korean hulless barley cultivars. Viral resistance was estimated in experimental filed of Honam agricultural research institute for 3 years. Length and number of seminal and adventitious roots were examined for evaluation of root growth in both field and green-house conditions 30 days after seeding. Dominant viral infection occurred in Korean hulless barley by Barley yellow mosaic virus (BaYMV) in fields; however, susceptible cultivars were infected by either BaYMV, Barley mild mosaic virus (BaMMV) or both. Only four cultivars, including Donghanchalssalbori, Kwangwhalssalbori, Namhossalbori and Naehanssalbori, presented stable resistance to viral infections. Susceptible cultivars to viral infection in fields showed shorter seminal root length and fewer adventitious root number than resistant cultivars. Resistant cultivars showed better root growth and significant difference in adventitious root length in green house conditions. Increase in the number of seminal roots in resistant cultivars was derived from decreased damage of roots by the viral infection compared to the susceptible cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.161-167
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• 1998

Root and shoot development of two rice (Oryza sativa L.) cultivars with different genetic backgrounds was studied with reference to their relative growth. Tongil type (indica-japonica hybrid) cultivar 'Kuemkangbyeo' and japonica cultivar 'Koshihikari' were grown in $5000^{-1}$ a Wagnar pots under flooded condition. Three plants with roots of both cultivars were taken in every phyllochron through the heading stage to record morphological characteristics of shoot and root system. Compared to Koshihikari, Kuemkangbyeo produced more tillers and had greater shoot weight and leaf area per hill. Length and weight of the root system in both cultivars increased exponentially with time. At the same time, root system development was significantly faster in Kuemkangbyeo than in Koshihikari after the panicle initiation stage. As a result, Kuemkangbyeo has a vigorous root system which consists of larger number of nodal roots compared to Koshihikari. Also, the root length and weight per unit leaf area of Kuemkangbyeo were larger than those of Koshihikari in the later half of growing period, which suggests possible higher physiological activity of the root system of Kuemkangbyeo which is known as a high-yielding cultivar. The relationship between root traits (crown root number, total root length, and root dry weight) and shoot traits (leaf area and leaf+culm dry weight) in both cultivars closely showed allometry until the flag leaf stage.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.197-202
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• 1989

This experiment was conducted to investigate the effect of growth medium in pots composed of upland soil(S), rice straw manure(M), carbonated rice hull(CRH), and their mixture on growth of tobacco cv. NC 82. The growth of shoot and root was vigorous in order of medium S+M+CRH>M>CRH>S. In M+S medium, root growth in the part of manure was superior to upland soil. But root growth of upland soil part in M+S plot was more vigorous than that in upland soil only. It is possibly due to be influenced by manure in M+S plot. Total length and weight of root, number of roots, and especially for development of adventitious root were closely related to shoot growth. Roots grown in upland soil part was brownish gray in color, while the roots in manure part was milky white. The milky white colored roots had longer life than others. It was concluded that root zone environments derived from several media in pots closely related to shoot growth and disease tolerance of tobacco plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.8-13
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• 1980

It was observed that the variety Suweon 258 has a good root system for nutrient and water absorption compared to variety Jinheung, because of larger secondary and tertiary roots inducting long and narrow adventitious roots in spite of less primary roots in number and shorter average length of primary roots.

• Journal of Environmental Science International
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• v.12 no.11
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• pp.1189-1196
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• 2003

The effect of boron and aluminum on the development of adventitious roots was studied in sunflower cuttings. Three-day-old seedlings were de-rooted and grown in nutrient solutions with or without boron and supplemented with different concentrations (from 50 to 700 ${\mu}$M) of aluminum. The number and length of the adventitious roots and proline content in adventitious roots in response to insufficient boron and aluminum stress were determined periodically. The micronutrient boron caused the development of numerous roots in the lower parts of the hypocotyl. A dose-response of boron-induced rooting yielded an optimum concentration of 0.1 mM boron. In the absence of boron, in the majority of the adventitious roots, a significant inhibition was observed with or without aluminum, indicating that the most apparent symptom of boron deficiency is the cessation of root growth. Increasing concentrations of aluminum caused progressive inhibition of growth and rooting of the hypocotyls, and a parallel increase in proline levels of adventitious roots. Supplemental boron ameliorated the inhibitory effect of aluminum, suggesting that aluminum could inhibit root growth by inducing boron deficiency. Ascorbate added to medium in the absence of boron improved root growth and induced a significant decrease in proline levels. These findings suggest that adventitious root growth inhibition resulting from either boron deficiency or aluminum toxicity may be a result of impaired ascorbate metabolism.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.14-19
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• 2008

The experiment was investigated the effects of lower root zone temperature on shoot and root growth of 'Akihime' strawberries in aeroponics in cold season. Root growth was decreased with decrease of root zone temperature, especially in lateral roots. Elongation of main roots was highest in $18^{\circ}C$ of root zone temperature. Number of lateral roots and length of lateral roots were lowest in $8^{\circ}C$ of root zone temperature. Lower root zone temperature resulted significantly in decrease of fresh weight of root and shoot and leaf area of strawberry. But there were no significant statistical differences in shoot fresh weight and leaf area in $8^{\circ}C$ and $13^{\circ}C$ of root zone temperature. Leaf length, leaf width and number of leaves of strawberry were decreased in lower root zone temperature. The results of this experiment will be utilized in the winter season cultivation for strawberry in hydroponics.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.270-277
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• 2021

Veronica rotunda var. subintegra (Nakai) T. Yamaz. is perennial herb belonging to the family Scrophulariaceae, native to Korea. Plant growth regulators, cutting mediums, cutting position, and leaf size were examined to investigate the requirements for cutting propagation of V. rotunda var. subintegra. This study was conducted over a period of 6 weeks from March to May 2017 in the Division of Plant Resources, Korea National Arboretum. For all treatments, survival and rooting percentage was 100%. In PGRs experiment, the number of roots and shoot length treated with 100 mg/L IBA treatment was significantly higher than that of NAA treatment. The shooting percentage was decreased with an increase of the PGRs concentration. In growing substrates experiment, the number of roots on commercial soil (61.2) was the highest, followed commercial + kanuma soil (45.7), and the lowest was kanuma soil (41.8). The shoot length treated with commercial soil (8.9 cm) was significantly greater than that of kanuma soil (4.1 cm). In cutting positions experiment, the number of roots treated with apical (56.6) was significantly higher than that of basal (38.8). In leaf-cut experiment, the number of roots and of shoot length treated with full leaf was significantly higher than that of half leaf. As a result, we recommend treating cuttings with 100 mg/L IBA treatment, commercial soil, apical position, and full leaf for successful cutting propagation of V. rotunda var. subintegra.