EFFECTS OF SHADING OF THE LEAF SHEATH ON THE GROWTH AND DEVELOPMENT OF THE TILLER STEMS OF KENTUCKY BLUEGRASS

1974 ◽  
Vol 54 (1) ◽  
pp. 47-53 ◽  
Author(s):  
W. E. CORDUKES ◽  
JOHN E. FISHER
Keyword(s):  
Growth And Development ◽  
Leaf Blade ◽  
Poa Pratensis ◽  
Growth Period ◽  
Kentucky Bluegrass ◽  
Leaf Sheath ◽  
Selection Program ◽  
Greenhouse Experiments ◽  
Wide Range ◽  
Effect Of Light

Two separate greenhouse experiments were conducted to measure the effects of shading of the leaf sheath on the growth and development of tiller stems of cultivars of Kentucky bluegrass (Poa pratensis L.). In the first experiment, four cultivars were grown as single plants and the initial stem was shielded, allowing the tip of the leaf blade to protrude slightly but retaining the sheath in darkness. As growth of the tiller proceeded, further shields were added in a similar fashion for a growth period of 234 days. The second experiment was similarly conducted but included nine cultivars representing a wide range of latitudinal origin. They were grown for a period of 188 days. All shielded stems were much longer than the unshaded stems and developed into long aerial rhizomes with vegetative rhizome-type buds with cataphylls, indicating the morphogenic effect of light on the leaf sheath and the apparent insensitivity of the leaf blade in this reaction. The growth of the stem and buds of the cultivars Windsor, Merion, Geary, and Belturf was less than the growth of stem and buds of Fylking, Pennstar, and Nugget, whereas growth of the uppermost leaf blade was greater. Fylking, Pennstar, and Nugget produced longer stems with many actively growing side shoots and a shorter upper leaf blade. This method of shading might be used as a screening technique in a selection program, particularly for Kentucky bluegrass.

THE EFFECT OF DAYLENGTH AND TEMPERATURE ON THE GROWTH OF SHIELDED AERIAL STEMS OF KENTUCKY BLUEGRASS

1981 ◽  
Vol 61 (3) ◽  
pp. 653-659
Author(s):  
W. E. CORDUKES ◽  
C. J. WILLIAMS
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Leaf Blade ◽  
Growth Traits ◽  
Poa Pratensis ◽  
Growth Period ◽  
Kentucky Bluegrass ◽  
Cultivar Selection ◽  
Origin Group ◽  
Short Days

Stems of 18 cultivars of Poa pratensis L. were shielded and grown in different environments to measure the effects of daylength and temperature with the object of determining the usefulness of this technique for cultivar selection. The four growth environments were: long days, low temperature (LDLT): long days, high temperature (LDHT); short days, low temperature (SDLT); short days, high temperature (SDHT). The mean growth period in the LDLT, LDHT and the SDLT environments was 123 days, but growth ceased in the SDHT regime after 78 days. Daylength and temperature significantly affected growth; cultivars that produced long stems had many nodes and a short upper leaf blade while short-stemmed cultivars had few buds and a long upper leaf blade. These distinct growth traits were stable and can thus be used in cultivar selection. Discriminant analyses assigned the cultivars to three groupings: group A cultivars originated from northern environments while group C cultivars were of southern origin. Group B cultivars were found at locations intermediate to those of A and C. Canadian cultivar performance for turf was closely allied to the three groupings.

scholarly journals Silicon Effects on Poa pratensis Responses to Salinity

HortScience ◽  
2010 ◽  
Vol 45 (12) ◽  
pp. 1876-1881 ◽  
Author(s):  
Qi Chai ◽  
Xinqing Shao ◽  
Jianquan Zhang
Keyword(s):  
Leaf Area ◽  
Leaf Blade ◽  
Saline Soil ◽  
Poa Pratensis ◽  
Germination Rate ◽  
Treatment Plant ◽  
Kentucky Bluegrass ◽  
Tiller Number ◽  
Individual Leaf ◽  
Turf Quality

Understanding turfgrass response to silicon (Si) application under salinity conditions is important to find a way to improve turfgrass salt tolerance for turf management. The objective of the study was to investigate effects of increasing amendment concentrations of Na2SiO3 on turf growth and distribution of Na+ and K+ in seedlings of kentucky bluegrass (KBG) (Poa pratensis L.) under salinity stress. This growth chamber experiment was consisted of a control (no salinity and no Si) and five Si amendment treatments (0, 0.24, 0.48, 0.72, and 0.96 g Si/kg saline soil) under 10 g·kg−1 salinity conditions. Seed germination rate was significantly increased after 12 d under 0.48 g·kg−1 Si treatment. Plant height and canopy coverage were increased under 0.72 g·kg−1 Si treatment after 40 and 44 d of treatment, respectively, and tiller number was increased under 0.96 g·kg−1 Si treatment compared with 0 Si under saline conditions. With the supplement of Si at 0.48 to 0.96 g·kg−1, the ratio of Na+/K+ in shoots was decreased and individual leaf area was increased compared with 0 Si under saline conditions. The increase in individual leaf area was mainly the result of the increase in the leaf blade length. The concentration of K+ in shoots was significantly increased, whereas the concentrations of Na+ in roots were significantly decreased under all Si amendment treatments. The content of K+ was higher in shoots than in roots, but the ratio of Na+/K+ in roots was higher than in shoots in all Si amendment treatments. The results indicate that under saline conditions, Si induced the transfer of K+ from roots to shoots but inhibited the absorption and transfer of Na+, which may contribute to better turf quality and growth with Si treatment under saline conditions.

scholarly journals Variation within Poa Germplasm for Salinity Tolerance

HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1517-1521 ◽  
Author(s):  
Joseph G. Robins ◽  
B. Shaun Bushman ◽  
Blair L. Waldron ◽  
Paul G. Johnson
Keyword(s):  
Water Resources ◽  
Salinity Tolerance ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Human Populations ◽  
Wide Range ◽  
Potential Part

As competition for water resources in areas of western North America intensify as a result of increasing human populations, the sustainability of turfgrass irrigation with limited water resources is questionable. A potential part of the solution is the use of recycled wastewater for landscape irrigation. However, as a result of high levels of salt, successful irrigation with recycled wastewater will likely need to be coupled with selection for increased salinity tolerance in turfgrass species. Additionally, salinity-tolerant turfgrass will allow production on soils with inherently high salt levels. The study described here characterized the relative salinity tolerance of 93 accessions of Poa germplasm from the USDA National Plant Germplasm System (NPGS). Control cultivars of tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) were also evaluated for comparison. Kentucky bluegrass accessions exhibited a wide range of LD50 (salinity dosage necessary to kill 50% of plants) values from 811 ECdays (PI 369296 from Russia) to 1922 ECdays (PI 371768 from the United States). Five kentucky bluegrass accessions exhibited salinity tolerance equal to or better than that of the tall fescue (LD50 = 1815 ECdays) and perennial ryegrass (LD50 = 1754 ECdays) checks. Thus, there is sufficient variation within this species to develop bluegrass with substantially higher salinity tolerance.

SAND ROOTZONES FOR KENTUCKY BLUEGRASS

1985 ◽  
Vol 65 (1) ◽  
pp. 137-143
Author(s):  
S. H. NELSON ◽  
G. L. McCLENNAN
Keyword(s):  
Hydraulic Conductivity ◽  
Root Growth ◽  
Growth And Development ◽  
Water Movement ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Root Production ◽  
Particle Sizes ◽  
The Third ◽  
Perched Water Table

The growth and development of Kentucky bluegrass was studied for 3 yr on eight sand blends consisting of variable particle sizes. All were perched over a coarse layer (6–12 mm diam). No differences in germination, establishment, or color over the 3 yr were observed. Without turf the hydraulic conductivity varied greatly in the sand blends. The high conductivity levels were greatly reduced with the developing turf. There was greater downward water movement in those plots with most of the finer particles removed and this greater percolation continued throughout the experiment as the turf developed. In the compacted plots, however, significant differences in percolation rates had disappeared by the third year. When most of the finer particles had been removed, there was a trend toward less total root production with a redistribution of roots to the middle portions of the profiles. This trend was more evident on the compacted plots. The study demonstrated that developing turf has an ameliorating effect on hydraulic conductivity on these vastly different sand blends and suggests that sands, even though not in the recommended range of particle size, can still offer relief to the compaction, drainage, and root growth problems encountered in Kentucky bluegrass playing fields.Key words: Poa pratensis, perched water table, hydraulic conductivity, root growth, compaction

COLD HARDINESS AND ICE TOLERANCE OF PASTURE GRASSES GROWN AND TESTED IN CONTROLLED ENVIRONMENTS

1986 ◽  
Vol 66 (3) ◽  
pp. 601-608 ◽  
Author(s):  
B. E. GUDLEIFSSON ◽  
C. J. ANDREWS ◽  
H. BJORNSSON
Keyword(s):  
Cold Hardiness ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Phleum Pratense ◽  
Grass Species ◽  
Meadow Fescue ◽  
Freezing Resistance ◽  
Reed Canarygrass ◽  
Red Fescue ◽  
Wide Range

A number of forage grass species were tested for cold hardiness and ice tolerance after growth and cold hardening under controlled conditions. Tests exposing cold-hardened plants to a single level of stress separated species into statistically similar groups but, in a number of cases, the stress was not sufficient to kill plants so the true cultivar rankings were obscured. Derivation of the 50% kill point from a wide range of levels of stress served to identify cold hardiness and ice tolerance levels of cultivars of 10 species. Ranked according to the most hardy cultivar of the species tested were: timothy (Phleum pratense L.), Kentucky bluegrass (Poa pratensis L.), meadow foxtail (Alopecurus pratensis L.), red fescue (Festuca rubra L.), meadow fescue (Festuca pratensis L.), tufted hairgrass (Deschampsia caespitosa L.), creeping foxtail (Alopecurus arundinaceus L.), berings hairgrass (Deschampsia beringensis L.), orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinaceae). LT50 values varied from −15.7 °C for timothy to −4.7 °C for reed canarygrass. Cold hardiness and ice tolerance were only loosely associated (r = 0.36). The most ice-tolerant species were berings and tufted hairgrasses and timothy with LI50 values of 50, 39 and 44 d, respectively.Key words: Acclimation, encasement, freezing, resistance

scholarly journals Isolation and Characterization of 88 Polymorphic Microsatellite Markers in Kentucky Bluegrass (Poa pratensis L.)

HortScience ◽  
2010 ◽  
Vol 45 (11) ◽  
pp. 1759-1763 ◽  
Author(s):  
Josh A. Honig ◽  
Stacy A. Bonos ◽  
William A. Meyer
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Rapd Markers ◽  
Poa Pratensis ◽  
Morphological Characteristics ◽  
Kentucky Bluegrass ◽  
Ploidy Levels ◽  
Isolation And Characterization ◽  
Wide Range ◽  
Polymorphic Microsatellite

Kentucky bluegrass (Poa pratensis L.) is an important facultative apomictic temperate perennial grass species used for both forage and cultivated turf. Through apomixis, this species is able to propagate diverse and odd ploidy levels, resulting in many genetically distinct phenotypes. A wide range of diverse cultivars and accessions of kentucky bluegrass have been previously characterized based on common turf performance or morphological characteristics as well as by random amplified polymorphic DNA (RAPD) markers. Although previous characterization efforts have provided valuable information, the use of both morphological characteristics and RAPD markers for genetic diversity analysis has limitations. In the current report, we developed and characterized 88 novel microsatellite markers for kentucky bluegrass. Polymorphism for each marker was assessed in 265 kentucky bluegrass cultivars, experimental selections, collections, and hybrids. The number of alleles for individual microsatellites ranged from four to 81 with an average of 38.3 alleles per simple sequence repeat. These polymorphic microsatellite markers would be useful tools for investigating genetic diversity, creation of genetic linkage maps, assessment of levels of apomixis in cultivars and experimental varieties, and identification of aberrant progeny in apomictic kentucky bluegrass breeding programs.

scholarly journals Distribution of Horseradish Peroxidase in Horseradish Plants

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 689a-689
Author(s):  
Mosbah M. Kushad ◽  
Nadeem A. Abbasi ◽  
Chunlin Xiao ◽  
A. Bratsch
Keyword(s):  
Horseradish Peroxidase ◽  
Growth And Development ◽  
Leaf Blade ◽  
Lignin Degradation ◽  
Lateral Roots ◽  
Plant Growth And Development ◽  
Main Root ◽  
Fuel Production ◽  
Leaf Petiole ◽  
Wide Range

Peroxidases are an enzyme family that displays a wide range of forms, functions, and distribution in the plant kingdom. Peroxidase extracted from horseradish is one of a few enzymes that had been widely used in industrial and clinical research. Horseradish peroxidase (HRP, EC 1.11.1.7, donor: hydrogen-peroxide oxidoreductase) has been used to estimate the levels of other enzymes, in immunoassay, bio-bleaching processes, and in lignin degradation for fuel production. Despite its extensive use, little is known about HRP distribution in horseradish plants. Four commercial horseradish cultivars (IL-647, IL-1069, IL-1573, and IL-1590) were evaluated for HRP activity in the main root, lateral roots, leaves, and leaf blades. HRP activity was highest in the main root followed by lateral roots. However, only a trace amount of HRP activity was detected in leaf blade and leaf petiole. IL-1573 has the highest HRP activity, while IL-647 has the lowest activity. Site of HRP synthesis and its distribution during horseradish plant growth and development will be described.

Herbicidal Potential of Rhizobitoxine

Weed Science ◽  
1973 ◽  
Vol 21 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Lowell D. Owens
Keyword(s):  
Growth And Development ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Chlorophyll Synthesis ◽  
Weight Basis ◽  
Grass Species ◽  
Digitaria Sanguinalis ◽  
Molar Basis ◽  
Plant Seedlings ◽  
Large Crabgrass

The bacterially produced phytotoxin 2-amino-4-(2-amino-3-hydroxypropoxy)-trans-3-butenoic acid (rhizobitoxine) was tested for herbicidal properties in comparison with 3-amino-s-triazole (amitrole) and 4-chloro-5-(dimethylamino)-2-(a,a,a,-trifluro-m-tolyl)-3(2H)-pyridazinone (metflurazone). In postemergence tests with various plant seedlings, rhizobitoxine and amitrole were approximately equal in phytotoxicity on a weight basis, and both were generally much more phytotoxic than metflurazone. Phytotoxicity of rhizobitoxine varied markedly among grass species. Sorghum (Sorghum bicolor(L.) Moench ‘Hegari’) was very sensitive to rhizobitoxine, large crabgrass (Digitaria sanguinalis(L.) Scop.) was moderately sensitive, wheat (Triticum aestivumL. ‘Thorne’) was tolerant, and Kentucky bluegrass (Poa pratensisL.) was very tolerant. In contrast, amitrole was almost as phytotoxic to bluegrass as to large crabgrass, and metflurazone had little effect on either. In a preemergence test with mustard (Brassica japonica(L.) Coss. ‘Southern Giant Curled’) rhizobitoxine was as effective as amitrole, when compared on a molar basis, in inhibiting chlorophyll synthesis and root growth and was superior in retarding overall growth and development.

scholarly journals Mathematical Modeling of Allelopathy. III. A Model for Curve-Fitting Allelochemical Dose Responses

2003 ◽  
Vol 1 (1) ◽  
pp. 154014203908444 ◽  
Author(s):  
De Li Liu ◽  
Min An ◽  
Ian R. Johnson ◽  
John V. Lovett
Keyword(s):  
Seedling Growth ◽  
Tall Fescue ◽  
Good Description ◽  
Poa Pratensis ◽  
Lolium Multiflorum ◽  
Kentucky Bluegrass ◽  
Lettuce Seedling ◽  
Red Fescue ◽  
Wide Range ◽  
Dose Responses

Bioassay techniques are often used to study the effects of allelochemicals on plant processes, and it is generally observed that the processes are stimulated at low allelochemical concentrations and inhibited as the concentrations increase. A simple empirical model is presented to analyze this type of response. The stimulation-inhibition properties of allelochemical-dose responses can be described by the parameters in the model. The indices, p% reductions, are calculated to assess the allelochemical effects. The model is compared with experimental data for the response of lettuce seedling growth to Centaurepensin, the olfactory response of weevil larvae to α-terpineol, and the responses of annual ryegrass ( Lolium multiflorum Lam.), creeping red fescue ( Festuca rubra L., cv. Ensylva), Kentucky bluegrass ( Poa pratensis L., cv. Kenblue), perennial ryegrass ( L. perenne L., cv. Manhattan), and Rebel tall fescue ( F. arundinacea Schreb) seedling growth to leachates of Rebel and Kentucky 31 tall fescue. The results show that the model gives a good description to observations and can be used to fit a wide range of dose responses. Assessments of the effects of leachates of Rebel and Kentucky 31 tall fescue clearly differentiate the properties of the allelopathic sources and the relative sensitivities of indicators such as the length of root and leaf.

scholarly journals Trinexapac-ethyl Increases Kentucky Bluegrass Leaf Cell Density and Chlorophyll Concentration

HortScience ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 787-789 ◽  
Author(s):  
E.H. Ervin ◽  
A.J. Koski
Keyword(s):  
Cell Density ◽  
Leaf Blade ◽  
Poa Pratensis ◽  
Chlorophyll Concentration ◽  
Acid Ethyl Ester ◽  
Kentucky Bluegrass ◽  
Carbohydrate Content ◽  
Cell Length ◽  
Cell Width ◽  
Structural Carbohydrate

The effects of trinexapac-ethyl (TE) on the anatomical and biochemical composition of turfgrasses and their implications for its field use are poorly understood. Two greenhouse experiments were conducted to determine if application of TE increased Kentucky bluegrass (Poa pratensis L.) leaf blade cell density, chlorophyll concentration, or structural carbohydrate content. Kentucky bluegrass (KB) sod was harvested from the field, established in greenhouse pots, and sprayed with 0.27 kg·ha-1 a.i. TE. Leaf blade samples were collected 4 weeks after treatment (WAT), fixed in glutaraldehyde, and embedded in Spurr resin. Photomicrographs of longitudinal leaf blade sections were used to determine cell density, cell length, and cell width. Chlorophyll and structural carbohydrate contents were determined at 2 and 4 WAT. Treatment with TE increased cell density and chlorophyll-b concentration, while reducing cell length, but structural carbohydrate content was unaffected. Chemical name used: 4-cyclopropyl-α-hydroxy-methylene-3,5-dioxo-cyclohexanecarboxylic acid ethyl ester (trinexapac-ethyl).

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