• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.73-85
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• 1997

Although zoysia grass (Zoysia spp.) has a lot of excellent chracteristics as warm-season grass, it have been limited in use due to slow establishment, low seed production, poor shade tolerance and other factors. Breeding trials have been continued from 1900's, much attentions have been paid especially in U.S.A., Korea and Japan recently. In U.S.A., more than 24 varieties had been evaluated at National Turfgrass Evaluation Program(NTEP) from 1991 to 1995 and some were regsistered as commercial. After the 6th International Turfgrass Research Conference at Japan in 1989, Japan Turfgrass In-corporation (JTI) sponsored by private companies and government carried out breeding programs for pest, salt, and shade tolerant and herbicide resistant varieties. JTI also has been trying to im-prove vigor and breed evergreen zoysia Korean breeders collected germplasms since 1960's. After USDA breeders came to Korean penesula in 1982, Korean breeders joined with USDA zoysia breeding project for several years. Many interspecific hybrids and natural selected varieties were breeded that period both in U.S.A and Korea. Breeding objectives were to extend green color period, improve leaf quality and density, and better leaf color at dormant stage. Since 1990's, zoysia grass breeding trials are getting more diverse in many points such as random amplified polymorphic DNA (RAPD) assay for ecotype identification. The objectives of this study are to evaluate germplasms in Korea, and also review the present status and future prospect in zoysia grass breeding in the world.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.333-340
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• 2011

Herbicide-tolerant Zoysia grass has been previously developed through Agrobacterium-mediated transformation. We investigated the effects of genetically modified (GM) Zoysia grass and the associated herbicide application on bacterial community structure by using culture-independent approaches. To assess the possible horizontal gene transfer (HGT) of transgenic DNA to soil microorganisms, total soil DNAs were amplified by PCR with two primer sets for the bar and hpt genes, which were introduced into the GM Zoysia grass by a callus-type transformation. The transgenic genes were not detected from the total genomic DNAs extracted from 1.5 g of each rhizosphere soils of GM and non-GM Zoysia grasses. The structures and diversities of the bacterial communities in rhizosphere soils of GM and non-GM Zoysia grasses were investigated by constructing 16S rDNA clone libraries. Classifier, provided in the RDP II, assigned 100 clones in the 16S rRNA gene sequences library into 11 bacterial phyla. The most abundant phyla in both clone libraries were Acidobacteria and Proteobacteria. The bacterial diversity of the GM clone library was lower than that of the non- GM library. The former contained four phyla, whereas the latter had seven phyla. Phylogenetic trees were constructed to confirm these results. Phylogenetic analyses of the two clone libraries revealed considerable difference from each other. The significance of difference between clone libraries was examined with LIBSHUFF statistics. LIBSHUFF analysis revealed that the two clone libraries differed significantly (P<0.025), suggesting alterations in the composition of the microbial community associated with GM Zoysia grass.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.265-269
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• 2021

This study was conducted to provide primary data through analysis of zoysia grass genetic resources to develop grass cultivars with beneficial novel properties. Zoysia grass (Zoysia. spp) is native to Korea, and is mainly propagated through stolons. However, since seed coat treatment technology was developed, the breeding of sexually reproductive grass variants has become possible, necessitating characterization of the floret appearance rate in the secured zoysia grass genetic resource before developing sexually reproductive cultivars. In this experiment, 549 grass lines were examined, revealing that florets appear in only 43 lines (7.81%). Survival rates after transplantation, and stolon generation rates displayed a significant positive correlation (Rho = 0.44). Survival rates after transfer, and rates of stolon production displayed very low correlations with floret appearance (Rho = -0.11 and Rho = -0.06). No significant results were obtained in 43 lines that displayed >20% floret appearance. To breed sexually reproductive grass variants, it is thus necessary to secure more genetic resources, considering the low rate of floret appearance. Finding traits that predict floret appearance at an early stage is also required.

• Asian Journal of Turfgrass Science
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• v.5 no.2
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• pp.95-114
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• 1991

This paper was designed to estimate the interaction of the first productivity, light conditions and to analyze the ecophysiological productivity, growth characteristics grown under various shading conditions in Zoysia japonica . The results summarized this experiment were as follows; 1.After transplanting the grass, increasing rate of leaf number and total leaf length was remarkahly high at the early growth stage in the control and the 30% shading plot. 2.The increasing rate of leaf area ratio (LA R) in all the experimental plot was remarkable high at the early growth stage after transplanting the grass. Especially, the control and 30% shading plot in compared with another plots, were remarkably high at rate of leaf area. 3.The length and the node number of rhizome in the control and 30% shading plot were also high and the difference was significantly large by the growth stage. 4.Chlorophyll content was very high at 36days after transplanting and then decreased. Increasing rate of shade resulted in its low content. The rate of chlorophyll a to b was decreased by in-creasing rate of shade. 5.The content of soluble sugar in the control and 30% shading plot was low at the early growth after transplanting and high at the late growth stage. Its content in the plot of 70% shading was remarkably low throughout the growth stage. 6.The increasing rate of standing plant in all the experimental plots was high at the early growth stage after transplanting. Increasing rate of shade was typically low through all the growth stage.

• Asian Journal of Turfgrass Science
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• v.2 no.1
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• pp.5-30
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• 1988

The object of this experiments was to know the salt tolerance of Fults and other lawn grasses. Fults, Olympic (Tall fescue, Festuca arundinacea Schred), Ceeping red fescue, Kentucky bluegrass and Zoysia grass (Z. japonica S.) were grown in hydroponics with vermiculite at various concentrations of NaCl. Hoagland's solution was used as the basic solution (control), and the concentrations of Cl to it were 1000, 2000, 3000, 4000 and l5OOOppm, respectively. Each was cultivated under the circumstances during 2 months. The results obtained are summarized as follows: 1.The growth of Fults, Olympic, Creeping red fescue and others were better at Cl lOOOppm than control. In the 5OOOppm application, Fescues become worse and 23.9% of them were withered. In concentration of Cl above 9OOOppm, it was impossible to live. 2.In the l0000~l1000ppm application, Olympic and Kentucky bluegrass were become worse and most of them died. 3.Fults were almost possible to live in the below of 9OOOppm, but they began to die in the above of 10000 ppm. 4.With the increasing concentration of Cl, plants were dwarfed and the number of stems, leaves and roots were reduced, but it was especially observed that the number of stolons of Creeping red fescue were increased at 1000~4000ppm. 5.Fults grass was the most salt tolerant turfgrass, but was impossible to live at salt level of about 36 millimhos (Exchange NaCI conductivity-ppm). Among the grasses, according to salt tolerance, they were arranged as follows. Fults > Zoysia japonica S. > Ky belugrass > Olympic grass > Creeping red fescue 6.The number of leaves, stems, tillers, and dry weight of Olympic grass, Fults and others were increased more at Cl 1OOOppm application than control, but in the above 4OOOppm application, those of plants were decreased. 7.The productivity of all grasses under the experiments was increased at 3.l75millimhos (Exchange NaCi conductivity ppm) in the concentration of Cl. The each dry-weight of Olympic, Creeping red fescue, Kentucky bluegrass and Zoysia grass was decreased at 8.85millimhos, and the weight of Fults grass was also decreased remarkably at 12.20millimhos. 8.As the result of this experiments, most plants grow normally at low concentration of NaCI-l000ppm. That seems to stimulate more the grasses to grow than non-salt.

• The Korean Journal of Soil Zoology
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• v.7 no.1_2
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• pp.45-49
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• 2002

Meloidogyne marylandi Jepson & Golden, 1987 is described from Zoysia grass collected in Cheonan, Korea. The nematode did not produce galls, and females were generally surrounded by a massive egg sac. Perineal patterns of female were a high to rounded arch with shoulders, wavy striae usually forming a rough. Vulva and anus were sunken. Second-stage juvenile body length was 390.3 $\mu\textrm{m}$ (290-430), tail length 55.1 $\mu\textrm{m}$ (49-59) and lateral field with 4 incisures. Male stylet length was 18.1 $\mu\textrm{m}$ (15-24), spicules length 26.2 $\mu\textrm{m}$ (23-29) and lateral field with 4-5 incisures.

• Asian Journal of Turfgrass Science
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• v.4 no.2
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• pp.125-131
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• 1990

This experiment was carried out in drder to study the changes of morphological characters and thatch weight on N-level and survey times N-levels were 0, 21, 28, 35, 42 and 49 g/m$^2$), respectively. The results are as follows. 1. Thatch weight was significantly different among survey times, and the interaction of survey time N-level. 2. The growth of Zoysia grass and thatch accumulation were incresed by higher N~level The highest value was obtained in all survey times. 3. Most survey characters and thatch accumulation was decreased by growth progressed. 4. Thatch increase rate(TIR) was the lowest at 28g Nm$^2$and T2-T3 period. 5. TIR was the positive significant correlated(P<0.05) with N-level, root weight, clipping weight and thatch weight.

• Asian Journal of Turfgrass Science
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• v.8 no.2
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• pp.101-103
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• 1994

In June 1994, the circular parch of zoysiagrasse(Zoysia japonica) occurred in golf courses in Kyeongnam, Kycooggi province, Korea The causal agent identified as Antonina graminis Maskell (Rhodeagrass scale). A. gramninis settle on a grass leaf shearh and stem, and then suck plants juices, causing daroaged plants to wither and die. Adult scales were legless, immobile, and shell-like protective cover with waxy and 2~Amm in size. Immature scales had three pairs of leg, and were mobile, O.4~ O.9mm in size.

• Asian Journal of Turfgrass Science
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• v.6 no.2
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• pp.89-98
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• 1992

Cultural characteristics and pathogenicity on the isolates of Rhizoctonia oryzae, R. oryzae-sativae and anastomosis group of R. solani and evaluation of selected fungicides on brown patch disease of creeping bentgrass and large patch disease of zoysia grass were studied comparatively. From effect of temperature on the rate of mycelia growth, the result indicated that the temperature groups were separated into four types : isolates of R. oryzae and R. oryzae-sativae had an optimum temperature of $30~35^{\circ}C$. Anastomosis groups of R. solani were separated into three temperature types as followings : high temperature type had an optimum temperature from 25 to $30^{\circ}C$, moderate type had grown from 20 to $25^{\circ}C$ for optimum and low temperature type had an optimum temperature of $20^{\circ}C$ but at $35^{\circ}C$ did not grow. Inoculation tests showed that AG-1( I A), AG-1( I B), bentgrass isolate of R. solani and R. oryzae were strongly pathogenic on creeping bentgrass, followed by AG-2-1, AG-4, AG-5 and AG-2-2 isolates of R. solani moderately to weakly. Zoysia grass isolate of R. solani and R. oryzae were strongly pathogenic on zoysia grass but AG-1( I B) and AG-5 isolates of R. solani showed moderately pathogenic. Capro(iprodione oxine-copper) and mytan(myclobutanil) were extremely effective against brown patch disease of creeping bentgrass and large patch disease of zoysia grass followed by thiopan (thiopanate-methyl) and pencycuron for brown patch disease and tolos(tolclofos-methyl) and thiopan for large patch disease.

• Asian Journal of Turfgrass Science
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• v.13 no.1
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• pp.1-20
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• 1999

This study was carried out to investigate the interaction between productivity and light condition and to analyze the material productivity and productive charactaristics under different hours of light in Zoysia japonica. 1. Rate increasement of leaf number and total leaf length was remarkably high at the early growth stage in the control and 9 hour light treatment. The rate gradually decreased as growth proceeded. But 3 hour treatment was very low in the rate from its early growth stage through the whole test period. 2. The increasing rate of leaf area ratio (LAR) in all the experimental plots was remarkably high at the early growth stage after transplanting the grass. The shorter photoperiod resulted remarkable lower increasement of LAR. 3. The rhizome growth rate of the 9 hour photoperiod was high contrast to the 3 hour photoperiod treatment. The increasing rate of node number was also showed similar trend. 4. Chlorophyll content was very high at the 36 days after transplanting and then decreased gradually. Chlorophyll content on 3 hours photoperiod plot severely decreased. The ratio of chlorophyll a to b was decreased significantly at short day treatment. 5. The content of soluble sugar was increased at shorter photoperiod. The highest ratio of sugar content was on August, 28 by HPLC method. Such a result was attributed to accumulation of sugar in spite of low synthesis of ploysacchrides, translocation by low consumption. 6. The increasing rate of standings in all light treatment was high at the early growth stage after transplanting. Short photoperiod treatment by 3hour showed especially low prganic productivity on Zoysia japonica.