The distribution and ultrastructure of the endophyte of toxic tall fescue

1985 ◽  
Vol 63 (1) ◽  
pp. 36-42 ◽  
Author(s):  
D. M. Hinton ◽  
C. W. Bacon
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Light And Electron Microscopy ◽  
Middle Lamella ◽  
Ultrastructural Level ◽  
Leaf Sheath ◽  
Host Cells ◽  
Parasitic Fungus ◽  
Acremonium Coenophialum ◽  
Relationship Of

The symptomless relationship of tall fescue grass (Festuca arundinacea Schreber) and its endophytic parasitic fungus, Sphacelia typhina (Fr.) Tul. (= Acremonium coenophialum fide Morgan-Jones et Gams), was studied with light and electron microscopy. The fungus was intercellular and was distributed throughout the plant with the exception of roots and leaf blades. The highest concentration of the fungus occurred in the base of the leaf sheath. In the seed the fungus was sequestered between the epithelial cells of the scutellum and the starchy endosperm. The seed embryo was not infected; infection was also not evident during the early stages of seed germination. At the ultrastructural level, the parasitic relationship was established in tissues where there were intercellular spaces. Micrographs indicated that the fungus did not separate the middle lamella of host cells, nor did it produce any obvious alteration in host cell morphology. Ultrastructural characteristics of the fungus depended on the age and type of fescue tissue. Hyphal cells possessed numerous vesicular and multivesicular structures, and in some sections, the hyphal walls were inordinately thickened and with or without an extracellular matrix. The fungus appeared to colonize the innermost areas of tissues in all infected organs and no signs of egress were ever detected.

Herbicides for Killing Tall Fescue (Festuca arundinacea) Infected With Fescue Endophyte (Acremonium coenophialum)

1989 ◽  
Vol 3 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Albert E. Smith
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Field Studies ◽  
Acremonium Coenophialum ◽  
Pasture Grass ◽  
Seed Field

The importance of tall fescue as a pasture grass is diminished when infected with the fescue endophyte. The availability of fungus-free seed has necessitated the development of systems to kill the infected sod before interseeding fungus-free seed. Field studies were conducted to evaluate the response of fescue sod to foliar-applied herbicides as single and sequential applications during the fall and spring. Sequential applications of paraquat at 0.14, 0.28, and 0.56 kg ai/ha in September and October and glyphosate at 0.84 and 1.7 kg/ha applied as single or sequential applications in September and October resulted in more than 90% kill of the tall fescue sod. Spring treatments of paraquat and glyphosate were less effective than those applied in the fall. Dalapon, fluazifop-P, HOE-39866 [glufosinate (proposed name)], sethoxydim, and simazine did not effectively kill the sod.

Leaf development in eight related grasses

1994 ◽  
Vol 123 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Y. Gao ◽  
D. Wilman
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Leaf Development ◽  
Festuca Arundinacea ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Leaf Expansion ◽  
Italian Ryegrass ◽  
Meadow Fescue ◽  
Rate Of Increase

SummaryLeaf development was studied in eight related grasses, grown in field swards cut at 5-week intervals, during the year of sowing and the subsequent year (1989 and 1990). The rate of leaf expansion was in the order Westerwolds ryegrass > Italian ryegrass (Lolium multiflorum), Italian ryegrass × meadow fescue > hybrid ryegrass > perennial ryegrass × meadow fescue, meadow fescue (Festuca pratensis), tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne). The order of grasses was similar, but not identical, for rate of leaf appearance, rate of leaf extension, weight of leaf blade emerging per shoot per week and rate of increase in length of exposed leaf sheath, and the order was approximately the reverse for weight per unit area of emerging leaf blade. The area per leaf blade increased greatly between May and October of the year of sowing, particularly in Westerwolds, Italian and hybrid ryegrasses and Italian ryegrass × meadow fescue. Area per leaf blade in tall fescue increased greatly between May and July of the year of sowing and May–July of the subsequent year. Rate of leaf expansion in meadow fescue was much higher in May of the year after sowing than in the previous May.

Preferences of Japanese Beetle and Southern Masked Chafer (Coleoptera: Scarabaeidae) Grubs Among Cool-Season Turfgrasses

1994 ◽  
Vol 29 (3) ◽  
pp. 398-406 ◽  
Author(s):  
Berry A. Crutchfield ◽  
Daniel A. Potter
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
The Other ◽  
Popillia Japonica ◽  
Feeding Preferences ◽  
Japanese Beetle ◽  
Acremonium Coenophialum ◽  
Cool Season ◽  
Lolium Perenne L ◽  
Choice Tests

Feeding preferences of Japanese beetle, Popillia japonica Newman, and southern masked chafer, Cyclocephala lurida Bland, grubs for six common cool-season turfgrasses were evaluated in choice tests in the greenhouse. On the basis of larval distributions, Popillia japonica consistently preferred perennial ryegrass, Lolium perenne L., over all other turfgrasses tested. In contrast, C. lurida showed no consistent pattern of preference. Presence of one grub species did not affect distribution of the other species. Grubs did not discriminate between tall fescue, Festuca arundinacea Schreb., infected with the endophyte Acremonium coenophialum Morgan-Jones & Gams and endophyte-free tall fescue.

scholarly journals Effects of Environmental Heat and Intake of Tall Fescue Seed Infested with Acremonium Coenophialum on the Acid-Base Status of Young Bulls

1996 ◽  
Vol 8 (2) ◽  
pp. 233-237 ◽  
Author(s):  
L. L. Mills Wallace ◽  
D. W. Vogt ◽  
R. J. Lipsey ◽  
G. B. Gamer ◽  
C. N. Cornell
Keyword(s):  
Heat Stress ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Environmental Temperature ◽  
Respiratory Alkalosis ◽  
Acremonium Coenophialum ◽  
Acid Base ◽  
Arterial Blood ◽  
Metabolic Compensation ◽  
Acid Base Status

Effects of high environmental temperature and dietary intake of tall fescue ( Festuca arundinacea) seed containing the endophyte Acremonium coenophialum on bovine acid-base status were studied using 3 groups of bull calves (2 Simmental, 1 Angus). Experimental animals were housed in controlled-climate chambers and subjected to gradual increases in environmental temperature, first while being fed an endophyte-free diet and then while being fed a diet containing 17% endophyte-infested fescue seed. Marked acid-base disturbances were not observed in any animals. In general, Pco2, HCO3-, base excess, and arterial blood pH values were reduced in response to heat stress, both with endophyte-free and endophyte-containing diets. In most individuals anion gap increased. These results reflected metabolic compensation for mild chronic alveolar hyperventilation and retention of organic acids. These findings suggest that, under conditions similar to those found during the summer in central Missouri, normal cattle should not be at great risk of developing respiratory alkalosis or other severe acid-base disturbances as a result of heat stress and/or intake of tall fescue endophyte.

Performance of growing lambs fed Acremonium coenophialum infested tall fescue (Festuca arundinacea Schreb.) hay

1992 ◽  
Vol 7 (1) ◽  
pp. 9-19 ◽  
Author(s):  
A.B. Chestnut ◽  
J.K. Bernard ◽  
J.B. Harstin ◽  
B.B. Reddick
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Acremonium Coenophialum

Herbage allowance and intake of cattle

1989 ◽  
Vol 112 (3) ◽  
pp. 395-401 ◽  
Author(s):  
C. T. Dougherty ◽  
L. M. Lauriault ◽  
P. L. Cornelius ◽  
N. W. Bradley
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Bos Taurus ◽  
Live Weight ◽  
Simulation Models ◽  
Acremonium Coenophialum ◽  
Bite Rate ◽  
Biting Rate ◽  
Essential Components ◽  
Angus Heifers

SummaryRates of intake of herbage and grazing time of beef cattle are essential components of simulation models of grassland agroecosystems. We studied the effects of herbage allowance on rates of intake and ingestive behaviour of twelve 2-year-old Angus heifers (Bos taurus)(364 ± 12 kg) grazing pastures of tall fescue (Festuca arundinacea Schreb.). A balanced change-over design and a novel tethering technique were used to estimate direct, residual and permanent effects of three herbage allowances on intake per bite, rate of biting and rate of intake. Herbage dry matter (D.M.) allowances, which were established by varying tether lengths, were 5, 9 and 13 kg (1·4, 2·5 and 3·6 kg/100 kg of live weight) and made available in circular plots of 15, 27 and 38 m2, respectively, for a single measured 2 h grazing session each day. Heifers grazing Kenhy tall fescue swards, composed of vegetative tillers and free from the endophyte Acremonium coenophialum, with herbage D.M. masses (> 5 cm) of 2000 kg/ha and D.M. allowances of 9 and 13 kg/2 h per heifer, ingested D.M. at 1·9 kg/h by taking bites averaging 800 mg D.M. at 38 bites/min. Allowances of 5 kg/2 h per heifer slowed the rate of intake to 1·3 kg/h by limiting D.M. intake per bite to 654 mg and biting rate to 35/min. Rate of D.M. intake of cattle grazing vegetative temperate grass swards appears to be ca. 0.5% of live weight per hour when allowance and availability of herbage are not limiting.

Increasing endophyte alkaloid expression in tall fescue by selecting for increased endophyte hyphal density

2007 ◽  
pp. 197-200
Author(s):  
M.G. Norriss ◽  
T.J. Frost-Smith ◽  
J.I.M. Sutherland
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Fungal Endophytes ◽  
Leaf Sheath ◽  
The Other ◽  
Apparent Correlation ◽  
Hyphal Density ◽  
Selection For ◽  
Breeding Pool ◽  
Hyphal Mass

Two AR542-endophyte infected tall fescue breeding pools were subjected to one cycle of selection for increased endophyte hyphal density. Hyphal density was assessed subjectively by microscopic examination of the leaf sheath. Levels of alkaloids produced by both the original and selected populations were subsequently measured during summer. Levels of lolines and peramine alkaloids increased significantly in one breeding pool (by 40% and 29%, respectively), with non-significant increases (by 24% and 2%) in the other breeding pool. The apparent correlation between observed hyphal density and levels of alkaloids supports the hypothesis that levels of lolines and peramine produced by fungal endophytes in their host grass are at least partly due to endophyte hyphal mass in the host sheath tissue. Measured lolines in one breeding pool were 21 times greater than the other, while sheath hyphal density was less. Possible explanations include contrasting patterns of hyphal colonisation beyond the sheath, and/or variation in the quantity of lolines produced per unit hyphal mass. Keywords: Neotyphodium coenophalium, endophyte, Festuca arundinacea, tall fescue, peramine, lolines, hyphal mass

scholarly journals SEED TRANSMISSION OF PYRROLIZIDINE ALKALOID ACCUMULATION CAPACITY IN TALL FESCUE

1985 ◽  
Vol 65 (2) ◽  
pp. 317-321 ◽  
Author(s):  
T. A. JONES ◽  
R. C. BUCKNER ◽  
P. B. BURRUS II
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Pyrrolizidine Alkaloid ◽  
Critical Factor ◽  
Seed Transmission ◽  
Systemic Fungicide ◽  
Gas Liquid Chromatography ◽  
Acremonium Coenophialum ◽  
Epichloë Typhina ◽  
Loline Alkaloids

Pyrrolizidine alkaloids (N-formyl loline and N-acetyl loline) and the endophytic fungus tentatively identified as Sphacelia typhina (Pers.) Sacc. (= Acremonium coenophialum Morgan-Jones and W. Gams), the imperfect stage of Epichloe typhina (Fr.) Tul., have both been suspected as etiological agents of summer syndrome in tall fescue (Festuca arundinacea Schreb.). This syndrome is a toxicological disorder characterized by poor cattle growth with visible symptoms accentuated by high ambient temperatures. Alkaloid levels were measured with gas-liquid chromatography and presence or absence of the endophyte was determined by cytological observation. The endophyte was controlled by soil incorporation of the systemic fungicide benomyl. Variability was found among the 11 parental clones of the synthetic ’Kenhy’ for level of loline alkaloids. Loline alkaloids were present in seed of endophyte-infected panicles but absent in seed of endophyte-free panicles of the same clone. Progeny accumulated loline alkaloids only when their female parents were infected. These results suggest that the seed source is the critical factor for both the endophyte status of a plant and its capacity to accumulate loline alkaloids.Key words: Sphacelia typhina (Pers.) Sacc, Acremonium coenophialum Morgan-Jones and W. Gams, Epichloe typhina (Fr.) Tul., benomyl, ryegrass staggers

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