Allelopathic Pollen Extract from Phleum pratense L. (Poaceae) Reduces Germination, In vitro, of Pollen of Sympatric Species

1995 ◽  
Vol 156 (4) ◽  
pp. 425-434 ◽  
Author(s):  
Stephen D. Murphy ◽  
Lonnie W. Aarssen
Keyword(s):  
Sympatric Species ◽  
Phleum Pratense ◽  
Pollen Extract ◽  
Phleum Pratense L

scholarly journals VARIATION IN DIGESTIBILITY DECLINE WITH ADVANCE IN MATURITY AMONG TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 323-328 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Forage Quality ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Single Population ◽  
Population Mean ◽  
Unit Increase ◽  
Selection For ◽  
Phleum Pratense L

The in vitro digestibility (IVD) of timothy (Phleum pratense L.) declines with advance in maturity. Forage quality reductions resulting from late harvesting could be minimized by developing cultivars with reduced IVD decline during maturation. This study examines variation for IVD decline among timothy genotypes. Clones originating from a single population were grown in simulated swards (100 plants m−2) at two Ontario locations in 1980 and 1981. Harvests were made every 5–6 d from early heading to late anthesis. Relative IVD declines were determined by regressing genotype performance on the population mean over several harvests. Considerable variation was found for relative IVD decline, but this parameter was not associated with IVD at early heading. Genotypes were identified which showed high IVD at heading and a 20% reduction in digestibility decline from heading to late anthesis. Changes in IVD were not associated with changes in the leaf content of forage. It is concluded that selection for reduced IVD decline, in addition to high digestibility at heading, might result in a 2–3% unit increase at anthesis.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, IVD decline

BARREN RING, A DESCRIPTION AND STUDY OF CAUSAL RELATIONSHIPS

1965 ◽  
Vol 43 (9) ◽  
pp. 1043-1054 ◽  
Author(s):  
J. I. Toohey ◽  
C. D. Nelson ◽  
G. Krotkov
Keyword(s):  
Bacterial Culture ◽  
Test Organism ◽  
Phleum Pratense ◽  
Pseudomonas Aureofaciens ◽  
Phytotoxic Activity ◽  
Number Of Microorganisms ◽  
Barren Soil ◽  
Bacteria And Fungi ◽  
Phleum Pratense L

A description is given of a rare soil disease, called "barren ring", which occurs in some old, deserted pastures. It is an expanding ring-shaped area of diameter up to 17 meters in which the vegetation is killed. Regeneration of normal vegetation occurs in the center of the ring. A number of microorganisms were isolated from the barren soil and tested for phytotoxicity in vitro. Of 24 pure strains of bacteria and fungi isolated, only one bacterium showed phytotoxicity to the test organism, Phleum pratense L. It was identified as a strain of Pseudomonas aureofaciens Kluyver. Bioautography of extracts of the bacterial culture showed that there are two compounds extractable in benzene which have both antibiotic and phytotoxic activity. However, it has not been established that this bacterium is the sole causal agent of the disease and it is suggested that it is caused by an association of microorganisms.

Leaf and stem nutritive value of timothy grown with varying N nutrition in spring and summer

1999 ◽  
Vol 79 (2) ◽  
pp. 223-229 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Nitrogen Deficiency ◽  
Phleum Pratense ◽  
Shoot Biomass ◽  
Negative Effect ◽  
N Deficiency ◽  
Rate Of Decline ◽  
Phleum Pratense L

Nitrogen fertilization is known to have a limited effect on the digestibility of grasses. In a previous paper, however, we reported that N deficiency increased the proportion of leaves in the shoot biomass, and hence, indirectly increased the digestibility of timothy (Phleum pratense L). This was mitigated by the direct negative effect of N deficiency on the digestibility of leaves or stems or both early in the regrowth. The objective of this study was to determine the direct effect of N deficiency on three parameters of nutritive value of leaves and stems of timothy cv. Champ. The evolution of leaf and stem in vitro true digestibility (IVTD), in vitro cell wall digestibility (IVCWD), and neutral detergent fiber (NDF) concentration of field-grown timothy fertilized with four rates of N was studied during a spring and summer regrowth cycle by sampling at weekly intervals. The rate of decline in leaf nutritive value in spring was greater than that in summer, and was less than the rate of decline in stem nutritive value during spring. Nitrogen deficiency consistently increased the NDF concentration of leaves but had a lesser effect on the NDF concentration of stems. Nitrogen deficiency decreased leaf IVCWD when the leaf-to-weight ratio (LWR) was high early in the spring and summer regrowth cycles. At the end of regrowth when LWR values were low, leaf IVCWD was greatest when no N was applied. As a result, the negative effect of N deficiency on the leaf IVTD during the early part of the spring and summer regrowth cycles diminished as the regrowth cycles progressed. Nitrogen deficiency had a limited effect on stem IVCWD. We concluded that the direct negative effect of N deficiency on the digestibility of the timothy shoot biomass can be attributed primarily to its effect on the NDF concentration and cell wall digestibility of leaves. Key words: Phleum pratense L., grasses, digestibility, cell wall, nitrogen

Leaf and stem nutritive value of timothy genotypes under varying N fertilization

2004 ◽  
Vol 84 (4) ◽  
pp. 1101-1104 ◽  
Author(s):  
G. Bélanger ◽  
A. Brégard ◽  
R. Michaud ◽  
G. F. Tremblay
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
N Fertilization ◽  
Phleum Pratense ◽  
Neutral Detergent Fiber ◽  
Acid Detergent Fiber ◽  
True Digestibility ◽  
Sib Families ◽  
Phleum Pratense L

Populations and half-sib families of timothy (Phleum pratense L.), contrasting in forage N concentration, were studied in two experiments conducted in growth rooms with varying N applications. They differed in leaf and stem in vitro true digestibility (IVTD) of DM and in vitro cell wall digestibility (IVCWD), and in stem neutral detergent fiber (NDF) concentration; this confirms the presence of genetic variability for leaf and stem nutritive value in timothy under both limiting and non-limiting N conditions. Key words: Digestibility, grasses, Phleum pratense, neutral detergent fiber, acid detergent fiber

scholarly journals The importance of cross-reactivity in grass pollen allergy

2014 ◽  
Vol 66 (3) ◽  
pp. 1149-1155 ◽  
Author(s):  
Ivana Aleksic ◽  
Olga Vuckovic ◽  
Katarina Smiljanic ◽  
Marija Gavrovic-Jankulovic ◽  
Vera Krsmanovic ◽  
...  
Keyword(s):  
Grass Pollen ◽  
Pollen Allergy ◽  
Immunoblot Analysis ◽  
Cross Reactivity ◽  
Phleum Pratense ◽  
Pollen Extract ◽  
Grass Pollen Allergy ◽  
Number Of Patients

According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense) and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions.

Leaf and stem nutritive value of timothy cultivars differing in maturity

1997 ◽  
Vol 77 (2) ◽  
pp. 237-249 ◽  
Author(s):  
G. Bélanger ◽  
R. E. McQueen
Keyword(s):  
Cell Wall ◽  
Dry Matter ◽  
Nutritive Value ◽  
Weight Ratio ◽  
Phleum Pratense ◽  
Cultivar Differences ◽  
Early Maturing ◽  
True Digestibility ◽  
Phleum Pratense L

The nutritive value of herbage is a function of the nutritive value of its component leaves and stems and their proportion in the herbage. A previous study indicated that the proportion of leaves in the herbage did not explain entirely the differences in in vitro true digestibility and NDF concentrations between early and late-maturing timothy (Phleum pratense L.) cultivars. It was therefore hypothesized that the leaves and stems of early and late-maturing cultivars differ in nutritive value. The evolution of leaf and stem nutritive value of field-grown timothy cultivars differing in maturity, and the relationships between parameters of leaf and stem nutritive value, and the leaf to weight ratio (LWR) were studied during primary growth in two experiments. On a given date, stems of early-maturing cultivars had in vitro true digestibilities of dry matter and cell wall up to 61 g kg−1 DM and 71 g kg−1 DM lower that those of late-maturing cultivars, respectively. The NDF concentration of stems of early-maturing cultivars was up to 32 g kg−1 DM greater than that of late-maturing cultivars. There were no cultivar differences in leaf in vitro true digestibilities of dry matter and cell wall, and NDF concentration on a given date. At a given LWR, however, the leaves and stems of early-maturing cultivars had greater in vitro true digestibilities of dry matter and cell wall, and a lower NDF concentration than those of late-maturing cultivars. Our results indicate that differences in herbage nutritive value at a given stage of maturity between early- and late-maturing timothy cultivars is explained by a greater nutritive value of leaves and stems of the early-maturing cultivars. Key words: Phleum pratense L., timothy, cultivar, digestibility, cell wall, leaf, stem

Delayed harvest affects mineral and NDF concentrations, and digestibility of timothy

2008 ◽  
Vol 88 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. Pelletier ◽  
G. F. Tremblay ◽  
G. Bélanger ◽  
P. Seguin ◽  
R. Drapeau ◽  
...  
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Metabolic Disorders ◽  
Nutritive Value ◽  
Phleum Pratense ◽  
Neutral Detergent Fiber ◽  
Fiber Concentration ◽  
Harvest Delay ◽  
Phleum Pratense L

A 1-wk delay after late heading in the harvest of timothy spring growth reduced dietary cation-anion difference (-17%), in vitro digestibilities of dry matter (-7%) and neutral detergent fiber (-10%), and increased neutral detergent fiber concentration (+5%). In summer regrowth, the harvest delay tended to have similar effects, but variations (1-6%) were smaller. Key words: Nutritive value, stages of development, Phleum pratense L., metabolic disorders

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