• Asian Journal of Turfgrass Science
• /
• v.3 no.1
• /
• pp.24-33
• /
• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.10
• /
• pp.1383-1388
• /
• 2001

To explore the factors restricting animal performance in relation to sward structure under a strip-grazing system, measurements of sward factors, herbage intake and milk production at 3 levels of herbage allowance were made on perennial ryegrass (Latium perenne L.) sward for 3 experimental periods. About 29%, 36% and 52% of the biomass offered was removed by grazing in high $(42kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$, medium $(30kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ and low $(18kg\;OM{\cdot}day^{-1}{\cdot}head^{-1})$ herbage allowance plots. Live leaf material was much more affected by grazing under different herbage allowance levels than dead material or leaf sheath. Grazing with a low herbage allowance decreased the proportion of live lamina by 93% and live lamina density by 96% before grazing. The density of dead material plus sheath was decreased by 17% after grazing at a low allowance, while it slightly increased or remained constant in the plots applied with high and medium allowances, respectively. The highly significant (p<0.01) correlations between herbage allowance and proportion (r=0.94) and density (r=0.91) of live lamina in residual sward after grazing were observed. Daily herbage intakes in the plots with high and medium levels of herbage allowance were not significantly different at $15.3kg\;OM{\cdot}head^{-1}$ in average, whereas with low level it decreased to $13.9kg\;OM{\cdot}head^{-1}$. Daily milk production was significantly (p<0.05) declined from $22.3kg{\cdot}head^{-1}$ (at high herbage allowance) to $19.7kg{\cdot}head^{-1}$ (at low herbage allowance). The data obtained clearly indicated that herbage intake and milk production were highly affected by the characteristics of residual sward, which were closely related to the level of herbage allowance.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.4
• /
• pp.285-290
• /
• 2009

A suitable system for plant regeneration has been established for perennial ryegrass (Lolium perenne L.). In order to investigate the effects of genetic variations of perennial ryegrass in tissue culture response, calli were induced from mature seeds of five cultivars, 'Topgun', 'Accent', 'Renenge GLX', 'Tetrellite', 'Bison' and plant regeneration frequency was compared. Significant differences were observed among the cultivars in both callus induction and plant regeneration. Genotype 'Accent' consistently performed best in the callus formation and plant regeneration. These results can be used useful for molecular breeding of perennial ryegrass through genetic transformation.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.3
• /
• pp.72-82
• /
• 2009

Research was initiated to investigate early establislment characteristics and germination pattern of perennial ryegrass (PR, Lolium perenne L.). Eight varieties of PR were evaluated in the study. An alternative environmental condition for a PR germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination pattern were measured and analyzed daily for 30 days. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and final germination rate. Germination rates were variable among the varieties, being 66.00 to 93.75% at the end of study. There were considerable variations in early germination characteristics and germination pattern among PR varieties. The first germination in all entries tested was initiated from 3 to 5 DAS (days after seeding) under ISTA conditions, being 2 days in differences among the varieties. It was 4 to 7 DAS in days to the 50% germination, being 1 to 3 days later from the first germination and three days were variable among them. Days to the 75% germination were 5.93 to 10.50 DAS under ISTA conditions, being 4.57 days in variety differences. Pennant II and Brightstar II were the fastest varieties. The slowest ones were Revenge GLX and Brightstar SLT. Considering days to the first germination, days to 75% germination, and germination pattern etc, Pennant II and Brightstar II were regarded as excellent varieties under ISTA conditions. From tills study, information on differences in germination characteristics and pattern would be usefully applied for golf course design and construction, when established with PR.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.22 no.2
• /
• pp.137-144
• /
• 2002

To investigate the short-term effects of N-supply form ( $NO_3\;^-$ or $NH_4\;^+$ ) and their level (0.2, 1.0 and 6.0 mM) on N assimilation and C metabolism were examined in perennial ryegrass (Lolium perenne L.). The increase in shoot fresh for $NH_4\;^+$-fed plants much less than $NO_3\;^-$ fed ones. Nitrate concentration in $NO_3\;^-$ -fed plants tended to increase with increasing the supply level, while that of $NH_4\;^+$-fed plants was nearly stable. Nitrate reductase activity (NRA) responded much quickly, showing a proportional increase within 24 h of feeding. NRA in $NO_3\;^-$ -fed plants at 72 h increased by 13.7, 40.3 and 84.0% in 0.2, 1.0 and 6.0 mM $NO_3\;^-$ -fed, but it was not changed in$NH_4\;^+$-fed plants regardless of the supply level. After 72 h of treatment the sugar accumulation in the plants supplied with 0.2 and 1.0 mM -$NH_4\;^+$fed was remarked. After 72 h of feeding, fructan hydrolysis was observed in all levels fur $NH_4\;^+$-fed plants, but only in 6.0 mM for $NO_3\;^-$ -fed plants.

• Weed & Turfgrass Science
• /
• v.3 no.4
• /
• pp.370-377
• /
• 2014

Research was initiated to evaluate cool-season grass (CSG) overseeding effects on coverage and species transition in Korean lawngrass (Zoysia japonica Steud.) and to determine CSGs and their seeding rate for a practical overseeding. Treatments were comprised of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), tall fescue (TF, Festuca arundinacea Schreb.) and their mixtures. Significant differences were observed in turfgrass coverage and species transition. Since overseeding, the coverage was highest in PR, followed by TF and lowest in KB. The highest coverage in polystand was associated with Mixture IV (TF 50 + PR 50) at a seeding rate of $150gm^{-2}$ which had highest PR and TF, but without KB. Regarding turfgrass transition, zoysiagrass recovery continued to come back up to 80% from late March. But it reduced after early October. Zoysiagrass in monostand was greatest in KB and lowest in TF, but variable in polystand. For the fast and great coverage in winter, it would be the best to apply with PR at $100gm^{-2}$ and equal combination of PR and TF by 1/2 in the mixture at $150gm^{-2}$. For the smooth spring transition to zoysiagrass, however, KB application at $50gm^{-2}$ is recommended.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.3
• /
• pp.165-170
• /
• 2009

A system for the production of transgenic plants has been developed for perennial ryegrass (Lolium perenne L.) via Agrobacterium-mediated transformation. Included in this study were two factors which may affect the gene transfer efficiency: concentrations of acetosyringone (AS, 0 to 300 ${\mu}M$), and co-culture period (1 to 7 days). Both factors were very important to achieve high efficiency gene transformation in the perennial ryegrass. The highest transformation efficiency was obtained when embryogenic calli were inoculated with Agrobacterium in the presence of 100 ${\mu}M$ AS with the culture medium for 5 days. Phosphinothricin resistant calli were developed with into complete plants. GUS histochemical assay, polymerase chain reaction (PCR) and Northern blot analysis of transgenic plants demonstrated that transgenes were integrated into the genome of perennial ryegrass. Using this protocol, it was possible to obtain transformants efficiently for further study.

• Asian Journal of Turfgrass Science
• /
• v.16 no.2
• /
• pp.65-73
• /
• 2002

Studies were conducted to determine the effect of undersoil heating on growth and quality of turfgrasses including Kentucky bluegrass (Poa pratensis L.‘Nuglade’), perennial ryegrass (Lolium perenne L.‘Accent’), tall fescue (Festuca arundinacea Schreb.‘Pixie’), and Korean lawngrass (Zoysia japonica Steud.) in simulated athletic field during winter season in Korea. Mineral contents in clippings of turfgrasses grown at different soil mixtures and temperatures were also analyzed. Undersoil heating (approximately 20$\pm$2$^{\circ}C$) was effective in protecting turfgrasses except Korean lawngrass from freezing injury and discoloration of shoots due to extremely cold temperatures during midwinter. Among turfgrasses grown at undersoil heating zone, tall fescue and perennial ryegrass showed the highest clipping weights and chlorophyll contents, respectively. However, anthocyanin contents of shoots were higher in Kentucky bluegrass. There was little or no difference in clipping weights, chlorophyll contents, anthocyanin contents and greenness of shoots between turfgrasses grown at two soil mixtures composed of 80% sand＋10% peat moss＋10% soil (v/v/v) and 80% sand＋20% pea moss (v/v). Contents of mineral K, Ca and Mg in clippings of cool-season turfgrasses were comparatively higher in a soil mixture composed of 80% sand＋10% peat moss＋10% soil, but little difference in contents of N and P was observed between two soil treatments. Results indicated that undersoil heating can improve quality of turf surface by thawing soil, melting snow, and maintaining shoot growth and greenness of turfgrasses in sports field during winter season.

• Asian Journal of Turfgrass Science
• /
• v.21 no.2
• /
• pp.147-154
• /
• 2007

In March of 2004, gray snow mold (Typhula blight) caused by Typhula spp. occurred on perennial ryegrass (Lolium perenne L.) and Kentucky bluegrass (Poo pratensis L.) at MuJu golf courses in Jeonbuk Province. Leaves in the affected areas were matted together and frequently covered with white to grayish mycelia. Sclerotia were formed on the leaf blade, leaf sheath, or crown regions. The fungus isolated from the diseased leaf formed whitish mycelium, clamp connections, and light pink to brown, irregular-shaped small sclerotia of less than 1.4 mm in diameter, which are characteristic to Typhula incarnata. Optimum temperature ranges for mycelial growth were $5^{\circ}C$ to $15^{\circ}C$. The causal organism was confirmed to be T. incarnata as the partial sequence of its ribosomal RNA ITS1 (internal transcribed spacer) region was 91% homologous to those of T. incarnata in GenBank database. Out of the 14 fungicides tested fur antifungal activity in vitro, 10 fungicides including iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+tebuconazole, and fenarimol completely inhibited fungal growth at their recommended concentrations. In the field test, these fungicides and others such as thifluzamide and thiram effectively controlled the gray snow mold of turfgrass with some variable degrees of control efficacies.

• Weed & Turfgrass Science
• /
• v.2 no.3
• /
• pp.274-282
• /
• 2013

Research was initiated to investigate early germination and establishment characteristics of perennial ryegrass (PR, Lolium perenne L.). An alternative condition was applied in Experiment I with 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA condition). Experiment II was conducted under $5^{\circ}C$ to $25^{\circ}C$ (natural condition). Significant differences were observed in germination percentage, germination speed and germination peak time. Seed germinating vigor was 66.00 to 93.75% under ISTA and 66.25 to 93.50% under natural conditions. Germination speed, measured as days to germination of 50% through 90%, was much faster with 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' under ISTA conditions. But it was faster only with 'Pennant II' and 'Brightstar II' under natural conditions. Germination peak time ranged 1.48 to 5.65 days under ISTA, while 2.17 to 10.63 days under natural conditions. Regardless of growing conditions, the shortest cultivars in peak time were 'Sonata', 'Pennant II', and 'Brightstar II' and the longest one 'Revenge GLX'. Considering germinating vigor, early germination speed and germination peak time, 'Pennant II', 'Brightstar II', 'Sonata' and 'Accent II' were regarded as excellent cultivars under ISTA conditions, while 'Pennant II' and 'Brightstar II' under natural conditions.