• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.4
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• pp.351-354
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• 1998

Centipedegrass (Eremochloa ophiuroides) is a popular lawn grass in the southeastern USA. It has a naturally light green color and grows well on a wide range of soil types. Studies show limited morphological variation present in centipedegrass germplasm. To obtain the high morphological variation, plants were established from the irradiated seed at 10 Kr, allowed to interpollinate and harvested bulk seed, and then irradiated again for the next cycles. Morphological characteristics were measured in the 5 genetic varition lines (TC201 : cv. Common and non irradiated, TC202 : 4th cycles, TC241 : 6th cycles, TC306 : 8th cycles, and TC318 : 5th cycles) induced by recurrent gamma radiation. The ranges of variation of recurrently radiated centipedegrass lines < TC202, TC241 and TC306 except TC318(TifBlair) > for the stolons per plant, total stolon length per plant, longest stolon length, leaf length and width at top-most exposed internode were wider than those of non-irradiated line (TC201). Recurrent gamma radiation was very effective to enlarge the ranges of variation of morphological characteristics in reproductive organ like stolons of centipedegrass. The effect of quantity of gamma ray irradiation cycles on the means and ranges of variation in the morphological characteristics of centipedegrass was not regularly tended.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.366-374
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• 2014

The study was conducted to investigate the possibility that epigenetic DNA methylation causes tree phenotypic variation in autotetraploids through evaluating the phenotypic variation and DNA methylation in autotetraploids occurred spontaneously from diploid trifoliate orange. Chromosome analysis confirmed that fourteen trifoliate orange trees of selected by flow cytometry were tetraploids (2n = 4X = 36) without any aneuploids. Chromomycin A3 staining determined that these trees were all autotetraploid with doubled chromosome set. Tree phenotypes, such as tree height and width, branching number, length, and angle, internode length, and leaf characteristics, varied in the autotetraploids. Chlorophyll indices were diverse in the autotetraploids, but photosynthetic rates were not significantly different. In addition, a wide range of variation was observed in stomatal density and guard cell length. Analysis of global cytosine DNA methylation showed that there was a variation of the methylation level in autotetraploids. More than half of 14 autotetraploids had at least 2 times higher methylation level than diploid trifoliate orange. The results indicate that tree phenotypic variation in autotetraploids might be related to global DNA methylation for reducing gene redundancy.

• Current Research on Agriculture and Life Sciences
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• v.13
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• pp.45-53
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• 1995

This research was conducted to investigate morphological and genetic variation of Allium victorialis val. platyphyllum which growed wild in Mt. Hambaek, Mt. Odae, and Ullungdo. The tree layer of Allium victorialis var. platyphyllum community in Mt. Hambaek and Mt. Odae was dominated by Quercus mongolica. The tree layer of Ullungdo generally consist of Fagus crenata var. multinervis, Acer triflorum, Sorbus commixta, and Tilia insularis. In the herb layer, Rumohra standishii, Trillium tschonoskii, and Lilium hansonii are common at Allium victorialis var. platyphyllum community in Ullungdo. The vegetation in Ullungdo was widely different from those in Mt. Hambaek and Mt. Odae by species composition. The result of Principal Component Analysis(PCA) and Canonical Discriminent Analysis of by the 8 characters showed that Allium victorialis var. platyphyllum could be classified into 2 groups: (one ; Mt. Hambaek and Mt. Odae, the other ; Ullungdo). In PCA, the major factors in the first principal component group was angle of leaf apex. Variation of band by isozyme GOT(glautamate oxaloaccetate transaminase) is similar between Mt. Hambaek and Mt. Odae. However, Ullungdo differed from Mt. Hambaek and Mt. Odae in variation of bands.

• The Korean Journal of Ecology
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• v.18 no.2
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• pp.231-241
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• 1995

I examined the relationship between allocations to plant size components such as plant height, total leaf weight, and nuber of branches and to reproductive components such as the number and weight of male and female fowers in three populations of the monoecious, wind-pollinated Ambrosia artemisiifolia. In particular, the two types of gender of plants, phenotypic and functional gender, were related to resource allocation. Mean values of all plant size and reproductive components differed significantly among the three populations. Such inter-population differences did not exist for both photosynthetic and reproductive efforts, Plant size components were mostly positively correlated with reproductive components among plants. However, the relationships between photosynthetic effort and reproductive components were largely negative and inconsistent among populations. The phenotypic gender was much lover than 0.5 in all of the three populations. Pairwise correlations between functional gender and each allocation measurement such as plant size components, reproductive components, photosynthetic effort, and reproductive effort were not consistent across the three populations. These results suggest that the gender of A. artemisiifolia measured as flower production responds sensitively to environmental conditions which might differ whithin as well as among populations.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.468-473
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• 1999

This study was carried out to assess the use of RADARSAT data which is C-band with HH polarization for the rice growth monitoring in Korea. Nine time-series data were taken by shallow incidence angle (standard beam mode 5 or 6) during rice growing season. And then, backscatter coefficient ($\sigma$$^{\circ}$) were extracted by calibration process for comparing with rice growth parameters such as plant height leaf area index(LAI), and fresh and dry biomass. Field experimental data concerned with rice growth were collected 8 times for the ground truth at the study area, Tangjin, Chungnam, Korea. At the maximum vegetative stage of rice, backscatter coefficients were the highest at the flooded rice field ranging from -4.4dB~-3.1dB. The temporal variation of backscatter coefficient($\sigma$$^{\circ}$) in rice field was significant in this study Backscatter coefficient ($\sigma$$^{\circ}$) of rice field was a little bit lower again after heading stage. This results show RADARSTA data is promising for rice monitoring.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.39-46
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• 1996

The experiment was conducted to inxvestigate matter production ability and growth characteristic variation for Italian ryegrass seed of introduced variety and the different seed production time of the next generation in paddy field at Iksan and Kyehwa experiment field from 1987 to 1988. Germination rate is good at seed production of 35 days before and after heading with introducced variety. Also, Early growth before wintering, dead leaf rate and regenerating day is same tendendy. Panicle numbers per hill like that and heading date is for 15~20 days after heading seed is late about three days, but 35 days before and after heading seed is early about one day. Fresh and drymatter yield at the different cutting time shows decrease in 15~25 days after heading seed but 35 days before and after heading seed is same or increase trend, it's notable at Kyehwa paddy field in reclaimed land. In case of feed value according to cutting time differ little against introduced seed.

• The Korean Journal of Ecology
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• v.6 no.1
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• pp.33-44
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• 1983

Vegetatiion structure and population dynamcis of pine needle gall midge were investigated from 1980 to 1982 at the southern part of Palgong mountain near Daegu. The results of investigation at the areas of A (pure stand), B(30% mixed forest) adn C(60% mixed forest) were as follow; Vegeation of 3 areas were not classified by the species diversity, but by the unequal distribution of Alnus hirsuta, Robinia pseudo-acacia, Lespedeza cyrtobotrya, Quercus variabilis and vitality of Pinus densiflora at the area C was low, due to shadow by broad-leaf trees. Soil environmental factors at 3 areas not characteristic, but the average of humus contents showed high significance and the order was A

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.1
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• pp.139-148
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• 1993

The present experiments have been conducted to find out the plant's growth environments habitate, mode of life, characteristic of photosynthesis, habit of growth and propagation. The results of this study are as follows: 1. Sambucus williamsii var. Coreana distributes around all sides of native site without having any relation to altitude, inclination and direction. 2. In the native site, Robinia pseudo - acacia and its neighboring species were Prunus yedoensis, Acer pseudo-sieboldianum, Lindera obtusiloba and Staphylea bumalda. From 21 to 41 types of species were located in the vegetation of the quadrat area. 3. According to the variation of leaf temperature with the result of the change of net photosynthetic rate, the optimum temperature for growth is $25^{\circ}C$. 4. The rooted rate of vegetative propagation was the highest at 100ppm IBA plot and the lowest at 200ppm BA plot. 5. The rooted rates of Sambucus williamsii var. coreana in perlite 50% bed, vermiculite bed and peatmoss 50%+sand 50% bed are higher than others.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.116-119
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• 2011

Pyrenophora graminea, the causal agent of leaf stripe disease, is an economically important pathogen of barley found worldwide. Forty-four isolates of diverse geographical origin within Syria were grouped into vegetative compatibility groups (VCGs) by demonstrating heterokaryosis by complementation tests using nitrate nonutilizing (nit) mutants. All isolates were grouped into three VCGs-1-A, 1-B and 1-C. No self-incompatibility was observed in any of the isolates tested. VCG 1-A was the most common group within growing regions in Syria and proved to be the most virulent of the VCGs identified. These data indicate that the level of virulence in P. graminea is related to VCG.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.649-654
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• 2005

This study proposes a particular approach to assess information about NDVI(Normalized Difference Vegetation Index) and LAI(Leaf Area Index) from the spectroradiometer and NOAA/AVHRR satellite data. AVHRR data were collected in twelves months over a one year period in 2004. We calculated 10-day composite NDVI using daily composite AVHRR surface reflectance products(1km spatial resolution). The 10-day composite NDVI have a great effect on the plant growth conditions. Considerably, NDVI was increased by developing muscle fiber tissue from April to May. Then the NDVI increased until the August and then decreased until February. The highest month was at August and the lower month was at December. The difference NDVI analysis using December and another months data was conducted, the results were provided information on the variation of vegetation coverage. The result suggest that a relationship established between the LAI and NDVI in 2004.