• Journal of the Korean Society of Tobacco Science
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• v.14 no.1
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• pp.3-11
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• 1992

The present study examined various environmental and cultural media conditions for in vitro "rescue" of cross-fertilized ovules formed through sexual crosses between Nicotiana rustica and N. tabacum cv. BY4. The response ovules to two cultural procedures was compared; ovules were cultured either separately or left attached to the placenta. Total yield of seedlings and percent of normal seedlings were increased by culturing individual ovules separately, rather than on excised placenta. Total yield of seedlings and number of normal seedlings were produced following in vitro culture of individual fertilized ovules of N. rustica X M tabacum cv. BY4 at four days post-pollination on NN medium containing 2% sucrose. In the in vitro culture of fertilized ovules, high sucrose concentration increased the frequency of seedlings of abnormal appearance. Therefore, sucrose should be supplied to developing ovules at gradually decreased concentrations. Culture of fertilized ovules from three to eight days after pollination gave increased number of seedlings, but with delayed cultral time the number of morphologically normal seedling were decreased. Hybrids were uniform in appearance and showed vegetative heterosis but flower characteristics were generally intermediate between those of the parents. All hvbrids evaluated were self-sterile.f-sterile.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.483-489
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• 2013

The abnormal seedlings, a common physiological anomalies, emerged during embryo rescue severely restricted grape breeding. To enhance the efficiency of the seedless grape breeding by reducing the production of abnormal seedlings in the course of embryo rescue, we investigated the effects of genotype, media type, embryo style, pre-chilling on the deformity rate of the abnormal seedlings during embryo rescue. The abnormal seedlings were firstly classified into seven categories based on their morphology. Our results indicated that the emergence of abnormal seedlings was highly dependent on the female parent genotype. Polyembryony was advantageous to diminish the number of abnormal plantlets and the germination rate of embryo was 100%. We also found that pre-chilling treatment could reduce the number of abnormal plantlets and promote the embryo germination. The abnormal plantlets were reduced significantly by the addition of $ZnSO_4$ $10{\mu}mol{\cdot}L^{-1}$ or mashed-banana $500mg{\cdot}L^{-1}$ to either embryo development or germination media. Transferring the abnormal seedlings onto the suitable fresh media in 4 weeks after embryo germination provided an effective way to transform them into normal seedlings.

• Journal of Korean Society of Forest Science
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• v.28 no.1
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• pp.36-42
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• 1975

In the beginning of the germination of Castanea creata seeds, seedlings with identical genetic characteristics from only one seed were produced by longitudinally splitting the radicle and epicotyl in half with a razor blade. The results are summarized as follows: 1. 2-8 genetically identical Castanca crenata seedlings were produced by longitudinally splitting the radicles and epicotyles from one to four in number in half with a razor blade 1-3 times about 7 days apart, while the seeds were germinating. 2. The proportion of success of splitting seedlings was very high (90-100%). When some of the spliting seedlings were withered a sprout appeared again and it was possible the seedling to revive. 3. The production rate, growth and T/R rate of seedlings which were split only once were lower that those of the seedlings which were split several times. 4. The growth and T/R rate of split seedlings which were one of no more than four seedlings produced from one seed showed no difference in comparison with normal seedlings, but in seedlings which were one of more than four, the growth and T/R rate were considerably decreased. 5. With the progress of growth, the external shapes of splitting seedlings completely returned to the original state, and no problems in growth, were found.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.273-279
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• 2020

BACKGROUND: After transplanting, the recent abnormal low temperature caused physiological disorders of pepper seedlings. This study was conducted to evaluate the effects of UV-A LED, a physical elicitor, on the chilling tolerance of pepper seedlings. METHODS AND RESULTS: Seedlings were continuously irradiated with 370 and 385 nm UV-A LEDs with 30 W·m^-2 for 6 d. After that, seedlings were exposed to 4℃ for 6 h and then recovered under the normal growing condition for 2 d. There were no significant differences in growth characteristics of UV-A treatments compared to the control. Fv/Fm values of two UV-A treatments were below 0.8. Electrolyte leakage in the control was increased by chilling stress, while 385 nm UV-A had the significantly lowest value. Total phenolic content and antioxidant capacity of two UV-A treatments significantly increased due to UV-A radiation. However, total phenolic content and antioxidant capacity of the control increased due to chilling stress and tended to decrease again during the recovery time. CONCLUSION: We confirmed that UV-A light was effective to induce the chilling tolerance of pepper seedling, and the supplemental radiation of 385 nm UV-A LED before transplanting could be used as a cultivation technique to produce high quality pepper seedlings.

• International Journal of Advanced Culture Technology
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• v.2 no.2
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• pp.15-18
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• 2014

This paper presents a sensor location decision making method respect to Container-Grown Seedlings in view of precision agriculture (PA) when sensors involved in tree container measure received signal strength (RSS) or time-of-arrival (TOA) between themselves and neighboring sensors. A small fraction of sensors in the container-grown seedlings system have a known location, whereas the remaining locations must be estimated. We derive Rao-Cramer bounds and maximum-likelihood estimators under Gaussian and log-normal models for the TOA and RSS measurements, respectively.

• BMB Reports
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• v.37 no.5
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• pp.527-532
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• 2004

A subtracted cDNA library specific to osmotic stress of Haloxylon ammodendron (Mey.) Bge seedlings was constructed by suppression subtractive hybridization (SSH) and T/A cloning. SSH was performed between two groups of H. ammodendron seedlings, one was cultivated in Hoagland (H) solution as a driver and the other group was treated with osmotic stress of the Hoagland solution by the addition of 400 mM mannitol (M), as a tester. The library consisted of about 400 recombinant clones, with the average size being of 500 bp, ranging from 300 bp to 1500 bp. Using a PCR-select differential screening kit, 100 recombinant clones were randomly chosen from the subtracted cDNA library and hybridized with forward,reverse subtracted and unsubtracted probes for two rounds. As a result, 21 positive clones specific to osmotic stress were obtained and some of them were verified by Northern blot analysis. The sequencing analysis of 6 positive clones and the following homology comparison to GenBank [blastx] non-redundant databases characterized that two sequences obtained in this experiment may contribute to novel drought-related genes.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.149-158
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• 2009

American sycamore seedlings were grown in chambers with two different ozone concentrations ($O_3$-free air and air with additional $O_3$) for 45 days. Both the control and the $O_3$ chambers included non-fertilized and fertilized plants. After 18 days of $O_3$ fumigation, seedlings were placed in a clean chamber for 27 days. Seedlings under ozone fumigation showed a significant decrease in pigment contents and photosynthetic activity, and a significant increase in lipid peroxidation. Fertilization enhanced physiological damage such as the inhibition of photosynthetic activity and the increase of lipid peroxidation under ozone fumigation. During the recovery phase, the physiological damage level of seedlings increased with ozone fumigation. In addition, physiological damage was observed in the fertilized seedlings. Superoxide dismutase (SOD) and glutathione reductase (GR) activities of $O_3$-treated seedlings increased up to 33.8% and 16.3% in the fertilized plants. The increase of SOD activity was higher in the fertilized plants than in the non-fertilized plants. Negative effects of ozone treatment were observed in the biomass of the leaves and the total dry weight of the fertilized sycamore seedlings. The $O_3$-treated seedlings decreased in stem, root and total dry weight, and the loss of biomass was statistically significant in the fertilized plants. In conclusion, physiological disturbance under normal nutrient conditions has an effect on growth response. In contrast, in conditions of energy shortage, although stress represents a physiological inhibition, it does not seem to affect the growth response.

• Journal of Plant Biotechnology
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• v.50
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• pp.255-266
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• 2023

Hyperhydricity is a physiological anomaly that significantly affects the growth and proliferation rate of crops cultivated by tissue culture techniques. To better understand the mechanisms that govern hyperhydricity incidence, we examined the effects of several media components, particularly cytokinin and gelling agents. These elements were found to be influential in both in vitro propagation and the development of hyperhydricity. Our study revealed that Arabidopsis thaliana seedlings had a greater manifestation of hyperhydricity symptoms when exposed to high cytokinin concentrations compared with the control. The presence of gelrite led to the manifestation of hyperhydric symptoms by elevated water build-up in the apoplast. The phenomenon of stomata closure was observed in the hyperhydric leaves, resulting in an increased ability to retain water and a decrease in the transpiration rates when compared to their respective control leaves. Additionally, histological examinations of the cross sections of hyperhydric leaves revealed an irregular cellular arrangement and large intercellular spaces. Furthermore, hyperhydric seedlings displayed impaired cuticular development in comparison to their normal seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.314-321
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• 1995

Experiments were conducted to obtain information on separation of nonviable seeds from seed lots of rape, Chinese cabbage and radish, by nondestrutive ways. Seeds were artificially aged at 90% relative humidity(RH) and 45$^{\circ}C$ to get different seed qualities. Large amounts of amino acids, proteins and sinapine were leaked from the dead seeds into water in the course of 4~8 hours soaking, while high quality seeds did not leak in all crops. Percentage of normal seedlings from nonfluorescent cellulose coated seeds of rape, Chinese cabbage and radish under ultraviolet light was 96, 96 and 74%, while that of fluorescent seeds was 8, 9 and 1%, respectively. Cellulose coating and storage of Chinese cabbage and rape seeds at 60 and 75% RH for 3 months and 90% RH for 2 months did not deteriorate seed quality. But percentage of normal seedlings from nonfluorescent radish seeds stored at 60, 75 and 90% RHs for 3 months was 63, 64 and 2%, respectively.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.748-756
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• 2016

In the present study, a lipopeptide (named AXLP14) antagonistic to Xanthomonas oryzae pv. oryzae (Xoo) was obtained from the culture supernatant of Bacillus amyloliquefaciens B014. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis demonstrated that AXLP14 consisted of surfactin homologs. The minimum inhibition concentration and minimum bactericidal concentration of AXLP14 against Xoo were determined to be 1.25 and 2.50 mg/ml, respectively. At a concentration of 0.613 mg/ml, AXLP14 strongly inhibited the formation of Xoo biofilm. AXLP14 also inhibited the motility of Xoo in a concentration-dependent manner. Applying AXLP14 to rice seedlings significantly reduced the incidence and severity of disease caused by Xoo. In Xoo-infected rice seedlings, AXLP14 strongly and continuously up-regulated the expression of both OsNPR1 and OsWRKY45. In addition, AXLP14 effectively inhibited the Xoo-induced up-regulation of the expression of the abscisic acid biosynthesis gene OsNECD3 and the abscisic acid signalingresponsive gene OsLip9, indicating that AXLP14 may protect rice against Xoo-induced disease by enhancing salicylic acid defense and interfering with the abscisic acid response to virulence.