• Horticultural Science & Technology
• /
• v.33 no.3
• /
• pp.331-339
• /
• 2015

This research was performed to determine the temperature requirements for embryo growth and radicle emergence of Hepatica asiatica Nakai, a perennial herb native to Korea. Seed viability, embryo growth, and radicle emergence were monitored in seeds exposed to various temperatures (10, 15, $20^{\circ}C$ and $30{\rightarrow}15^{\circ}C$). Laboratory experiments at various temperatures revealed that (1) embryo elongation occurred effectively between 10 and $15^{\circ}C$; (2) radicle emergence occurred only at $15^{\circ}C$; (3) a warm stratification (2-8 weeks at $30^{\circ}C$) was not required for embryo elongation and radicle emergence, and led to inhibition of radicle emergence; (4) application of gibberellic acid ($GA_3$) promoted embryo growth, but not radicle emergence. These results suggested that H. asiatica seeds have two separate mechanisms to overcome dormancy, either by $GA_3$ (morphological dormancy) or temperature (physiological dormancy), and warm stratification is not involved in breaking radicle dormancy. These findings indicate that H. asiatica seeds have morphophysiological dormancy.

• Mycobiology
• /
• v.29 no.4
• /
• pp.218-223
• /
• 2001

A rapid radicle assay for prescreening antagonistic bacteria to Phytophthora capsic4 causal agent of Phytophthora blight of pepper was developed. Sixty-four bacterial strains with in vitro antifungal activity selected out of 1,400 strains isolated from soils of Ansung, Chunan, Koyang, and Paju, Korea in 1998 were used for development of the bioassay. Uniformly germinated pepper seeds dipped in bacterial cells for 3 hours were placed near the edges of growing mycelia of P. capsici on water agar containing 0.02% glucose. Five-week-old pepper plants(cv. Nockwang) were inoculated to compare with results of the radicle assay developed in this study. For plant inoculation, pepper seeds were sown in potting mixtures incorporated with the bacterial strains, then transplanted into steam-sterilized soils 3 weeks later. Plants were hole-inoculated with zoospores of P. capsici 2 weeks after transplanting. Disease incidence and severity were determined in radicle and plant assessments, respectively. In radicle assay, six strains, GK-B15, GK-B25, OA-B26, OA-B36, PK-B09, and VK-B14 consistently showed the significant(P=0.05) disease reduction against radicle infection by the fungus, four of which also did in plant assessments. Strains OA-B36 and GK-B15 consistently reduced the fungal infection in both the radicle assay and the plant assessment. Therefore, prescreening strains using the radicle assay developed in this study followed by plant assay could reduce time and labor, and improved the possibility of selecting antagonistic bacteria for control of Phytophthora blight of peppers.

• Journal of Plant Biology
• /
• v.11 no.3
• /
• pp.8-17
• /
• 1968

A grafting method, cleft grafting of ordinary dormant scion into an inverted radicle of a germinated seed was tested with good success for chestnut as well as for walnut trees. It was seen that verticilate roots which were produced from the cut and of radicle after grafting made a complete union with scion and made healthy development to produce a successful graft. The radicle before secondary rootlets emerged from its rooting zone was proved to be best stock for inverted radicle grafting. The dormant but was also used for grafting scion with success in this method. Though green house grafting gives higher survival, field grafting was also feasible by this method. Those early growing geason after grafting, the later development of root system and the shoot of the graft were to be studied in the future.

• The Korean Journal of Ecology
• /
• v.19 no.5
• /
• pp.385-392
• /
• 1996

Changes in polyamine titers and enzyme activities during radicle growth of Glycine max were studied in order to investigate the effect of ferulic acid in regulation of polyamine biosynthesis. Among eight compounds used, gallic acid stimulated the radicle growth and ferulic acid inhibited it significantly. During the radicle growth of Glycine max, the content of putrescine was shown the highest level at the second day, while at the fourth day spermidine was the highest and spermine followed. Ornithine decarboxylass (ODC, EC 4.1.1.17) seems to be responsible for biosynthesis of putrescine. As the concentration of ferulic acid (0.001, 0.01, 0.1 mM) treated increased, the content of spermine was gradually enhanced and putrescine was increased at 0.001~0.01 mM, decreased after 0.1 mM concentration but spermidine was not affected. Ferulic acid elevated ODC and S-adenosylmethionine decarboxylass (SAMDC, EC 4.1.1.50) activity. ODC activity was increased more than 120% and SAMDC activity was increased about 50% more than that of the control. Diamine oxidase (DAO EC, 1.4.3.6) activity was enhanced about 20% at low concentration, decreased after then.

• Korean Journal of Organic Agriculture
• /
• v.14 no.4
• /
• pp.411-420
• /
• 2006

Indole-3-acetic acid (IAA) biosynthesis by bacteria occurs widely in rhizospheres. Bacterial species able to synthesize IAAmay be exploited for beneficial interactions in crop management systems. The objective of this study was to determine the response of ivyleaf morningglory (Ipomoea hederacea) seedlings to IAA and to an IAA-producing rhizobacterum, Bradyrhizobium japonicum isolate GD3. IAA solution and isolate GD3 suppression of seedling growth measured as radicle length and biomass depended on IAA concentration. Seedling radicle length was significantly reduced by ca. 29% with more than $1.0{\mu}M$ of IAA solution, compared to the control, 48 h after application. The cell concentration at 50% growth reduction ($GR_{50}$) of the seedling radicle was IAA production by isolate GD3 at $10^{4.82}\;cfu$, the cell concentration for 50% growth reduction ($GR_{50}$) of seedling radicle was 0.24 iM, which was much lower than the IAA solution concentration ($117.48{\mu}M$) required for $GR_{50}$. Therefore, excess IAA production by isolate GD3 may be more detrimental to morningglory radicle growth than standard IAA solution. Results confirmed involvement of IAA in suppressive effects of isolate GD3 on morning-glory seedlings grown in a hydroponic system.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.6
• /
• pp.938-945
• /
• 2018

Salinity stress is an important environmental problem that adversely affects crop production by reducing plant growth. The impacts of rhizobacterial strains to alleviate salinity stress on the germination of Lactuca sativa and Raphanus sativus seeds were assessed using different concentrations of NaCl. Plant growth-promoting rhizobacteria (PGPR) strains were also examined to improve the early germination of Chinese cabbage seeds under normal conditions. Lactobacillus sp. and P. putida inoculation showed higher radicle lengths compared with non-inoculated radish (Raphanus sativus) seeds. LAP mix inoculation increased the radicle length of lettuce (Lactuca sativa) seedlings by 2.0 and 0.5 cm at salinity stress of 50 and 100 mM NaCl concentration, respectively. Inoculation by Azotobacter chroococcum significantly increased the plumule and radicle lengths of germinated seeds compared with non-inoculated control. A. chroococcum increased the radicle length relative to the uninoculated seeds by 4.0, 1.0, and 1.5 cm at 50, 100, and 150 mM NaCl concentration, respectively. LAP mix inoculation significantly improved the radicle length in germinated radish seeds by 7.5, 1.3, 1.2, and 0.6 cm under salinity stress of 50, 100, 150, and 200 mM NaCl concentration, respectively. These results of this study showed that PGPR could be helpful to mitigate the salinity stress of different plants at the time of germination.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.3
• /
• pp.158-161
• /
• 1991

Horizontal starch gel electrophoresis, follow by enzyrne-specific staining, separate and visualize several legume esterase isozyme. Using extracts prepared from cotyledon, radicle and plumule of legume seedlings germinated 5 days. The results were as follows. 1. The number and staining intensity of esterase isozyme bands varies depending on the plant species. tissues and developmental stage. 2. Bands in the cotyledon of field bean seedling expressed 4 and 1 in radicle. 3. In soybean cultivars, cotyledon of IIwangkum-kong had 3 bands and 1 band in the examined tissues of Paldal-kong and Jangkyung-kong seedling. 4. The cotyledon and radicle of french bean seedling had 3 bands, respectively. 5. The highest esterase isozyme activity appears to be expressed in the cotyledon and radicle of french bean, as indicated by intensity of stain, with the Paldal-kong particulary active.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.15 no.2
• /
• pp.80-86
• /
• 1995

High salinity common in reclaimed soil can reduce germination of crop seeds and aftermath its establishment and production. The experiment was done to measure germination and radicle elongation of berseem, subterranean, white clover and Italian ryegrass as Control under different temperature and NaCl concentrations. Onehundred seeds of berseem (Trifolium ulexandrinum cv. Bigbee). suberranean (T. suhterruneum, cv. Nungarin), white clover (T. repens, cv. Regal) and Italian ryegrass (Lolium mulriflorum, cv. Terafloum) were placed in petri dishes with a sheet of filter paper replaced every two days, and then exposed to 0, 12.5, 25. 50, 100 and 200mh4 of sodium chloride in darkened growth chambers controlled with 10, 15 and $20^{\circ}C$. Percent germination and radicle elongation were measured. Beneem clover showed greatest daily percent germination among the cloven. That of subterranean clover, moreover, was higher than that of white clover till 4 days after imbibition but the reverse result was true thereafter. Although germination of Italian ryegrass was delayed with decreased at 200mM of NaCl of $20^{\circ}C$. at 200mM of under$15^{\circ}C$ , and at higher than lOOmh4 of all level of temperature, respectively. Berseem clover had greatest radicle length under the same concentration of NaCl regardless of temperature treatment while radicle elongation of subterranean and white clover was repressed over 50-100mM of NaC1. The slope of linear regression equation between concentration of NaCl and percent germination declined under all temperature treatment in order of berseem, subterranean and white clover whereas the reverse result was showed in radicle length.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.4
• /
• pp.273-278
• /
• 2013

BACKGROUND: Total petroleum hydrocarbons (TPH), which are main materials of soil contamination by oil, are a term used for any mixture of hydrocarbons. Korea Ministry of Environment established the maximum permissible level of TPH in farmland by 500 mg/kg, and reported that the TPH level of soil in 266 installation such as gas station, transport company, and military unit ranged from 1,356 to 55,117 mg/kg and were much higher than the maximum permissible level in 2011. METHODS AND RESULTS: To determine the effect of TPH on crops, we investigated the effect of gasoline, kerosene, and diesel on the germination and radicle growth of mainly consumed crops. The germination rates of control in investigated all crops ranged from 80.0-100%. The germination and radicle growth in majority of investigated crops were not inhibited even at 2,500 mg/L. However, germination in onion, leek, and green perilla and radicle growth in leek, rape, tomato, and green perilla were significantly inhibited by increasing concentrations of gasoline, kerosene and diesel treatment. Germination and radicle growth inhibition of green perilla by kerosene and diesel were the highest, the percent inhibition at the 500 mg/L were 100 and 98.6%, 100 and 88.2%, respectively. 50% inhibition of germination in green perilla by kerosene and diesel were 39.96 and 29.87 mg/L, and 50% inhibition of radicle growth were 52.76 and 177.96 mg/L, respectively. Conclusion(s): These results suggest the possibility that the maximum permissible level of TPH might to be established general level with exception by crops.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.3
• /
• pp.194-197
• /
• 2014

BACKGROUND: Herbal extracts have been screened for their inhibitory effect of seed germination and root development on weeds, but there is a scarcity of reports for crop growth regulation. The objective of this research was to develop a growth inhibitor on Brassica campestris, and its effective extraction method from herbal medicine extract. METHODS AND RESULTS: Eighty four herbal medicine extracts were tested for their plant growth inhibition activity on B. campestris. The alcohol extracts of Artemisia annua, Cinnamomum cassia, and Mentha arvensis inhibited over 30% of germination and the extract of A. annua, and C. cassia inhibited over 70% of radicle growth at 0.1 % w/w treatment. The partially purified extracts of A. annua, and C. cassia with dichloromethane and hexane showed stronger radicle growth inhibition than the crude extracts on B. campestris. The diethyl ether extract of A. annua showed a similar 50% radicle growth inhibition ($RI_{50}$ = 45 mg/L) to its partially purified extract with dichloromethane or hexane, but the diethyl ether extract of C. cassia showed a worse $RI_{50}$ than the purified extract. CONCLUSION: The alcohol extracts of A. annua, and C. cassia showed potent radicle growth inhibition properties on B. campestris. Diethyl ether proved to be a good solvent for simple extraction from A. annua.