• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.31-40
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• 2020

This study aimed to investigate the effects of climate change on the survival and growth performance of Pinus densiflora and Larix kaempferi seedlings using open-field experimental warming and precipitation manipulation. We measured the survival rate, root-collar diameter, and height, and then calculated the seedling quality index (SQI) of 2-year-old seedlings under 6 treatments [2 temperatures (TC: Control; TW: Warming) × 3 precipitation manipulations (PC: Control; PD: Decreased; PI: Increased)] and performed a two-way ANOVA to test for differences.The air temperature of the warming plots was 3℃ higher than that of the control plots, while the precipitation manipulation plots received ±40% of the precipitation received by the control plots. Temperature and precipitation treatments did not significantly affect the survival rate of P. densiflora; however, the SQI of P. densiflora decreased with increasing precipitation. In contrast, the mortality rate of L. kaempferi increased with increasing temperature and decreasing precipitation. Furthermore, in L. kaempferi, TC × PI treatment resulted in the lowest SQI with a significant interaction effect observed between the two factors. In summary, low seedling production and quality should be expected in P. densiflora as precipitation increases and in L. kaempferi as temperature increases or precipitation decreases. These results indicate species-specific sensitivities to climate change of two plant species at the nursery stage. With the occurrence of global warming, the frequencies of drought and heavy rainfall events are increased, and this could affect the survival and seedling quality of tree species. Therefore, it is necessary to improve nursery techniques by establishing new adaptation strategies based on species-specific growth performance responses.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1144-1149
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• 2011

The occurrence of Korean pine (Pinus koraiensis) advance growth has been noticed in the deciduous oak forest being adjacent to the mature Korean pine plantation. the korean pine seedlings in the forest were regenerated naturally from harvested and transported Korean pine seeds and cones by rodents, mainly red squirrels. Mongolian oak (Quercus bariabilis), which formed dominant overstory, had close-to-normal distributions of height, diameter and age classes. Korean pine, which dominated the understory, had the reverse J-shaped height, diameter and age distributions that are expected of a shade tolerant species. Growing in the summer shade of the oak, Korean pine seedling had slow, but steady height growth during the past four decades. Total biomass of Korean pine seedling ranged from $2,835-8,541kg\;ha^{-1}$ and biomass allocation of Korean pine seedling was follows : stem (with bark) > foliage > branches > roots. Korean pine seedlings allocated more biomass to foliage and branches compare to planted Korean pine. The smaller root/shoot ratio of Korean pine seedling in the site is to believed to be result of competition for light. Contents of N and K for Korean pine seedling were greatest in foliage follow by branches, stem ad roots, while content of P was greater in the order of foliage > roots > stem > branches.

• Journal of Climate Change Research
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• v.7 no.1
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• pp.9-17
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• 2016

Climate change affects plant responses on physiological characteristics and growth, and Pinus densiflora, one of the major tree species in Korea, are expected to be particularly vulnerable to rising temperature and increased precipitation. This study was conducted to investigate the effects of an open-field warming and precipitation manipulation on physiological characteristics and growth of P. densiflora seedlings. Seedlings of 2-year-old P. densiflora were planted in April, 2013, in open-field nursery located at Korea University. The air temperature of warmed plots had been set to be $3^{\circ}C$ higher than the control plots using infrared lamps. Precipitation was manipulated to be 30% lower or higher than the control, using transparent panels and drip irrigation. Net photosynthetic rate, total chlorophyll content, seedling height, root collar diameter and biomass were measured from April, 2014 to April, 2015. The increase in new shoot biomass from warming was statistically significant, with the biomass in warmed plots about 2-fold higher than in the control plots in 2014 and 2015. This result might be related to advanced bud burst and increased occurrence of abnormal new shoots in warmed plots. Meanwhile, the results of net photosynthetic rate, total chlorophyll content, seedling height, root collar diameter and total biomass from warming and precipitation manipulation were not statistically significant, but tendencies of lower net photosynthetic rate and higher seedling height and biomass in warmed plots compared to the control were shown. Such might be speculated as results of the extended growth period. When root to shoot (R/S) ratio was calculated from the biomass data obtained in April 2014 and April 2015, increased R/S ratio was observed regardless of the treatments applied. Drought tolerance of P. densiflora and particularly low annual precipitation observed in 2014 were suggested as the possible reasons.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.649-654
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• 1995

This study was conducted to investigate the utility and agronomic characteristics and use of cytoplasmic. male-sterile (CMS) haploid plants derived from interspecific cross between (male-sterile NC82$\times$burley21) F$_1$ plant (Nicotiana tabacum L.) and Nicotiana africana. Abundant seeds of high germinability were obtained when Nicotiana tabacum (cytoplasmic male-sterile F$_1$ plants) is pollinated by Nicotiana africana. Most of seedlings died at the cotyledonary stage. The remaining seedlings are viable F$_1$ hybrids or maternal haploids that can be easily distinguished. Number of interspecific Fl hybrids and matermal haploids per capsule obtained from the interspecific cross between cytoplasmic male-sterile tobacco F$_1$ plants and N.africana yielded 2.2 and 0.5 plants, respectively. Out of 149 CMS haploid plants obtained from interspecific cross, 102 plants showed green type while the others were yellow type for leaf and stem. This results agreed with the genetic ratios expected among haploid plants from the F$_1$ hybrids heterozygous for two recessive genes of yellow color of burley tobacco plant. Out of 83 CMS haploid plants inoculated with TMV, 48 plants showed resistant, while the others was susceptible. It agreed with the expected genetic ratios for a single dominant gene of TMV resistance. CMS haploid plant will be useful as a source material for breeding of CMS doubled haploid lines

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.65-71
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• 2014

Cacalia firma is a perennial plant in Asteraceae, Parasenecio that distributed in Korea, China, and Japan. As dietary style changes for well-being life, consumer's demand of functional food and organic vegetables is getting increased. This study was conducted to investigate the optimum light conditions of P. firmus in forest farming. One year old seedlings were grown under four different light conditions 10%, 20%, 30%, and 50% of sunlight by shading (equals 50%, 30%, 20%, and 10% relative brightness respectively) and non-treated control under full sunlight. They were analyzed for early growth and physiological response. Seedlings grown under 75% shading showed similar height, root growth, and leaf water content to control. However, their leaf length, width, and total leaf area were increased, which caused increased leaf dry weight and total dry weight. Especially, seedlings under 95% shading showed 40% increase in height and more leaf growth and leaf water content, although they had shorter main root length and root collar diameter than control. In addition specific leaf area (SLA) and leaf area ratio (LAR) were higher than control and indicated that they were statistically significant difference from control. Higher SLA refers thinner leaf thickness, higher LAR means larger leaf area. The results indicate seedlings under 95% shading have higher water content, thinner leaf, and wider lightinterception areas. It is plausible that P. firmus is active in chlorophyll activities and carbon dioxide assimilation at even lower light conditions. These results suggest that the optimum light level of P. firmus for artificial cultivation in forest farming ranges from 75~95% shading (20%-10% of relative brightness). When salability as 'sanchae' (wild edible greens) is considered, P. firmus could be cultivated under 75% shading in forest farming and expected to have better taste and higher yield. We suggest these results as basic data of P. firmus for possible forest farming.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.78-81
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• 2006

Freshly harvested, immature (green) seeds of North American ginseng (Panax quinquefolius L.) were stratified for up to 3 years in plastic pails in controlled environment rooms at $5{\pm}1^{\circ}C$ for 9 months and then $21{\pm}2^{\circ}C$ for 3 months (Trt. 1, regular stratification), or continuously at $-2{\pm}0.2^{\circ}C$ (Trt. 2), or continuously at $3{\pm}0.2^{\circ}C$ (Trt. 3). During stratification at -2 and $3^{\circ}C$ embryos did not grow. On seeding in the field embryos grew rapidly and resultant seedlings were comparable to those from regularly stratified seed. Seedling emergence rate was acceptable at the industry expected rate of 68% after one year of storage, but not after two years storage when it declined to 17.5%. Seed rot was so severe in year 3 that no planting was carried out. Seedling and second year growth were similar at the three stratification temperatures; most importantly, root dry weight (economic yield) was similar. Low-temperature storage of freshly-harvested North American ginseng seed is an acceptable method for short-term retention of propagating material.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.29-34
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Phytophthora capsici, PI201232, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI201232 were inoculated with zoospore suspension of P. capsici at 36 days after seeding. Most of the $F_1$ seedlings survied the inoculation and this suggested that resistance is dominant over susceptibility. The number of survived plants in $F_2$ population was, however, much less than the killed. All the plants in a backcross to Keystone Resistant Giant #3 were killed. Therefore, the observed numbers did not fit the expected ratio for segregation of one or two dominant alleles as previously reported. The resistance to P. capsici appeared to be inherited in a quantitative mode in evaluation of root rot. Resistant individuals in $F_2$ population were selected and a breeding program for incorporation of the resistance to P. capsici by backcross method is continued.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.204-204
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• 2017

In recent years the growth rates of world agricultural production and crop yields have slowed because of rapid urbanization but the agriculture mechanization implies the use of various power sources and improved farm tools and equipment to enhance the efficiency of utilization of various crop input. Therefore the current study was conducted to investigate the growth characteristics of seedlings treated with plant growth regulators for the production of seeds suitable for mechanical formulations of soybeans and red beans. The seeds of Uram bean and Arary red bean were sown in 128 well plug tray as the testing varieties. Three growth inhibitors such as 0.05% hexaconazole, prohexadion-calcium, and 0.1% diniconazole were treated and fifteen representative plants were collected from each treatment at 2, 5, 7, 13, 16, 17, 19, and 20 days interval after treatment. The collected plants were examined for the growth atributes such as plant height, root length, leaf area and chlorophyll. The growth promoter was treated at the 13th day after treatment with growth inhibitor and treated with 0.1% concentration of Pomina ($GA_{4+7}$ 1.8% + 6-benzylaminopurine 1.8%) and Nonaji (gibberellic acid 2% + $GA_{4+7}$ 2%). Initially the growth data was recorded to examine the effect of growth inhibitor, while after treatment with growth promoters, the growth attributes were recorded at 4th and 7th day. As a result of measuring the growth parameter of soybean, the inhibitory effect was shown in the aerobic treatment at the ground level at the 7th day after treatment. At the 4th day of growth promoting agents treatment, the stimulation effect of non - treated plants was greater than that of formalin treatments. As a result of measuring the growth attributes of red bean, In the latter part of the growth, at the 4th day after the growth promoter treatment. This study was able to confirm the effective growth regulators and treatment periods for each crop, and it was possible to control the growth of seedlings. Based on these results, it can be expected that the basis of seedling production technology of crops which is necessary for sowing and transplantation mechanization of agriculturle field can be established.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.380-391
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• 2014

Plants as well as crops are damaged by a combination of the hot and dry winds that has been a major factor in the reduction of crop production. A means to protect them from damaging conditions is to consider a coating material. In this study, we established laboratory screening methods to find a coating material to protect a crop from rapid transpiration caused by various factors. In a test measuring the weight loss of kidney bean seedlings for 6 days, Avion treatments decreased its weight loss (P=0.05). Owing to long-time spend in completing this assay, we performed a more simple method using a cobalt chloride paper strip, which changes from blue to red colors under water condition. Beewax, guagum, paraffin liquid, soybean oil, and PE-635 gave a waterproofing effect above 37 and 43% at 0.5 and 1 h after treatment, respectively. However, these tested materials did not show significant waterproofing results at 2 h. Although the methods produced reasonable results, a screening method to obtain more objective data is needed. An alternative is to use an instrument that can detect the transpiration of crop leaves. In a preliminary test using barley leaves, a portable photosynthesis system showed transpiration inhibition of 2% soybean oil and 10 times-diluted Avion under field conditions. In another test using the leaves of maize seedlings and apricot tree, 2% liquid paraffin and plant oils such as apricot oil, linseed oil, olive oil, and soybean oil showed significant transpiration inhibition (P=0.05). Especially, paraffin liquid and soybean oil selected from above tests gave good transpiration inhibitory effects against rice at 2%. In addition, the mixture of 2% soybean oil and a spreader showed more elevated inhibition results comparing with soybean oil or the spreader alone indicating that the spreader may be attributed to more uniform diffusion of the hydrophobic material onto the leaf surface of maize seedlings. The hydrophobic material coated physically the stomata and cuticle layers on leaf surfaces of rice. These hydrophobic materials screened in this study are expected to be used as plant coating materials.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.59-65
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• 2012

Plant growth-promoting effects of rhizobacterial inoculation obtained in pot experiments cannot always be dependably reproduced in fields. In this study, we investigated the effect of inoculation with Azospirillum brasilense and Methylobacterium oryzae, which have displayed growth promoting effects in several pot experiments, on growth and fruit yield of red pepper under field condition in a plastic-film house. Four rows spaced 90 cm apart were prepared after application of compost ($10Mg\;ha^{-1}$), and red pepper seedlings (Capsicum annum L., Nocgwang) were transplanted in each row with 40-cm space. Experimental treatments were consisted of A. brasilense CW903 inoculation, M. oryzae CBMB20 inoculation, and uninoculated control. Twelve plots, 10 plants per plot, were allotted to the three treatments with four replicates in a completely randomized design. At the time of transplanting, 50 mL of each inoculum ($1{\times}10^8cells\;mL^{-1}$) was introduced into root zone soil of each plant, and re-inoculated at 7 and 14 days after transplant. Plant growth and fruit yield were measured during the experiment. Both A. brasilense CW903 and M. oryzae CBMB20 could not promote growth of red pepper plants. All growth parameters measured were not significantly different among treatments. There were large variations in fruit yield recorded on plot basis, and no statistically significant differences were found among treatments. The failure to demonstrate the expected plant growth promoting effect of the inoculants is possibly due to various environmental factors, including weather and soil characteristics, reducing the possibility to express the potential of the inoculated bacterial strains.