• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.277-281
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• 2001

Embryogenic callus induction and plant regeneration methods were developed for native Kentucky bluegrass (Poa pratenes L.) ecotypes. Mature caryopses and immature inflorescences (20 mm in length) of 4 native ecotypes and 5 foreign cultivars were plated on MS medium (30 g/L sucrose, 3 g/L Phytagel) supplemented with 1 mg/L 2,4-D, and cultured in the dark at 24$^{\circ}C$. Most explants formed calli, but more embryogenic calli were induced from the explants of immature inflorescences than caryopses which produced mostly non-embryogenic rooty calli. In P77 ecotypes, immature inflorescence explants formed embryogenic calli with the rate of 62~95%, and those of field-grown plants were more efficient than greenhouse-grown ones in embryogenic callus induction. Plantlets were regenerated from the embryogenic calli when they were transferred to hormone-free MS medium, and grew to maturity without morphological variations in greenhouse.

• Asian Journal of Turfgrass Science
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• v.14 no.1
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• pp.251-256
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• 2000

The purpose of this study is to select the appropriate herbicide, which is needed to control the bentgrass in kentucky bluegrass(Poa pratensis) fairway effectively. The best control of bentgrass was observed at /$0.3mL\m^2$ of dithiopyr applied on Kentucky bluegrass. A field experiment was conducted to determine the priming effects on seed germination of Kentucky bluegrass. Ground covering rates by turfgrass were investigated under field conditions for 70 treatments by thirty days after treatment. The solid matrix priming(SMP) treatments on Kentucky bluegrass reduced the number of days requited for emergence and improved final cover ratings. Primed seeds of Kentucky bluegrass (incubated for five days at $20^{\circ}C$) resulted in most rapid germination and covering rate.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.373-375
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• 2006

• Proceedings of the Turfgrass Society of Korea Conference
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• 2002.02a
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• pp.18-21
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• 2002

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.269-274
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• 2018

In the middle of May 2018, typical red thread disease symptoms were observed on Kentucky bluegrass (Poa pratensis L.) on a golf course, which locates at Yangsan, Gyeongnam province in Korea. Irregular-shaped patched symptoms were observed in fairway of golf course. The foliar symptom was dried out and faded to straw color and tip of the grass leaves were tangled like thread. Early morning, infected and tangled leaves were covered with the pinkish gelatinous antler-like structure (sclerotinia) as a typical red thread disease symptom. Causal fungal pathogens were isolated from the symptom in Kentucky bluegrass. The fungal culture characteristic on potato dextrose agar color of colony was pale pink and conjugated hyphae, sclerotium of irregular shape was pale pink and 3~5mm diameter in size. The pathogen was identified as Laetisaria fuciformis based on morphological and culture characteristics as well as molecular characteristics. Pathogenicity test was verified on the Kentucky bluegrass by Koch's postulates. This is the first report of red thread disease occurrence in Kentucky bluegrass by L. fuciformis in Korea.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.115-121
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• 2003

In this study, plant regeneration and Agrobacterium tumefaciens-mediated transformation Kentucky bluegrass(Poa pratensis L.) were evaluated. Three different types of calli were produced depending on the combinations of growth regulators. They were non-friable brown or gray-colored callus (type I), compact, friable and yellow or white-colored callus (typeII), and soft, watery translucent callus with differentiated structure (typeIII). The highest regenerable organogenic callus (typeII) was obtained on the medium containing 1mg/L, 2,4-D and 0.1mg/L BA. Additionally, the production of typeII calli increased significantly when AgNO$_3$ was added to the callus induction and growth medium. The highest frequency of multiple shout formation from typeII callus was obtained on MS medium containing 1mg/L BA and 1mg/L Thidiazuron(TDZ). The organogenic calli(typeII) were inoculated with Agrobacterium tumefaciens strain EHA101 harboring the binary vector pIG121Hm with $\beta$-glucuronidase gene, and various factors were found to influence the transfer-DNA delivery efficiency. The highest transient GUS activity was observed on typeIIcallus. In the present work, we reported the first transient GUS activity of Kentucky bluegrass mediated by Agrobacterium tumefaciens. Our system may contribute to genetic improvement for breed-recalcirtrant grass species, Kentucky bluegrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.265-270
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• 2004

Plant regeneration from seed-derived callus of Kentucky bluegrass(Poa pratensis L. cv. Kenblue) was investigated. Callus induced on the medium supplemented with 2 mg/L 2,4-D and 0.2 mg/L BAP showed highest frequency of plant regeneration on the regeneration medium supplemented with 1 mg/L NAA and 5 mg/L kinetin. Callus induced in the dark condition showed higher regenerability than that induced in the dim light. MS medium was better than N6 and B5 medium in enhancing plant regeneration. Maltose was superior to sucrose in plant regeneration as carbon source in the medium.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2006.04a
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• pp.162-165
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• 2006

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.113-124
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• 1999

This study was carried out to know the oviposition preference site of chestnut brown chafer ( CBC ), Adoretus tenuimaculatus and its temporal activity and spatial distribution in green. Larval distribution was also investigated in golf courses for the control of CBC. CBC collected from Yongwon Golf Club in Chinhae, Tongdo Golf Club in Yangsan, Gyeongsan Province, Daegu Golf Club in Gyeongsan, Kyeongbuk Province, Dongrae Golf Club laid more eggs on broableaf of Zoysia matrella than Z. japonica, broadleaf+middleleaf of Z. matrella, Poa pratensis, and P. annua. The number of CBC egg was $19.7\pm$6.7 in Z. japonica,$ 1.7\pm$1.5 in P. pratensis, $1.3\pm$1.5 in sandy loam and $5.7\pm$2.9 in sand. Acitivity time of CBC in a day was the peak at 20:00 and continued to 24:00. CBCs adults were more collected from outside of golf courses whichhad many host plants than roadside courses. Density of white grubs was significantly different in fairway only. CBCs were more collected at tee and fairway than green. Density of white grubs was $54.6\pm$100 in broadleaf of Z. matellia and $37.7\pm$33.8 in P. pratensis at the back tee of the 7th hole in Dongrae Golf Club.

• Asian Journal of Turfgrass Science
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• v.4 no.2
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• pp.133-144
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• 1990

This experiment was carried out to study the effect of pure nitrogen fertilization on botanical composition of grassland in 1987~ 1988 under practical conditions at the " Federal Institute for Agriculture in the Alps" in Austria. The application rates were 0, 30, 60, 90 and 120kg/ha/cut, the cutting regimes 3-, 4 , 5- and 6-cuts/year. The results were as follows: 1. Only PK fertilization resulted in higher botanical composition of Trifolium repens among legumes in grassland, which was increased by cutting frequency .2. Nitrogen fertilization on three-cut areas resulted in higher existence of generally valuable tall grasses such as Arrhenotherum elatius Trisetum flavescens and Dactylis glomerata . On the other hand, nitrogen fertilization on four-, five- and six-cut areas showed mainly Doctylis glomerato and Poa pratensis appearance. 3.For some cases, appearance of less valuable grasses, herbs and weeds such as Agropyron repens, Poa trivialis, Poa annua, Setoria viridis, Aegopodium podagra rio, Men landrium rubrum, Taraxacum officlnale, Achillea millefolium, Rorippa sylvestris and Polygonum ocleulare was *Bundesanstalt fur alpenlandische Landwirtschaft Gumpenstein(A-8952 Irdning, 6sterreich) increased on medium and high rates of N fertilized areas. 4.Reduction of sward density may also diminish the advantages of nitrogen fertilization and may be threatened by mainly high dressings of nitrogen combined with too late utilization of the sward. 5.Location altered the efficiency of nitrogen fertilization on botanical composition.mposition.