scholarly journals Effects of the Fungal Endophyte, Neotyphodium lolii, on Net Photosynthesis and Growth Rates of Perennial Ryegrass (Lolium perenne) are Independent of In Planta Endophyte Concentration

2006 ◽  
Vol 98 (2) ◽  
pp. 379-387 ◽  
Author(s):  
MARTIN J. SPIERING ◽  
DENNIS H. GREER ◽  
JAN SCHMID
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Growth Rates ◽  
Net Photosynthesis ◽  
Fungal Endophyte ◽  
In Planta ◽  
Neotyphodium Lolii

scholarly journals Survival of endophyte-infected ryegrass seed buried in soil

1999 ◽  
Vol 7 ◽  
pp. 151-156
Author(s):  
D.E. Hume ◽  
M.P. Rolston ◽  
D.B. Baird ◽  
W.J. Archie ◽  
M.R. Marsh
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seed Viability ◽  
Seed Storage ◽  
Fungal Endophyte ◽  
Grass Species ◽  
Soil Conditions ◽  
Neotyphodium Lolii ◽  
Viable Seeds ◽  
One Year

Emergence of volunteer perennial ryegrass (Lolium perenne L.) from seed buried in soil may contribute to the ingress of ryegrass in newly sown pastures. To investigate this, ryegrass seed infected with fungal endophyte (Neotyphodium lolii) was buried in nylon bags under pasture at two depths and at two sites (Palmerston North, Lincoln) in early/mid-autumn 1998. Seed bags were removed from the soil at intervals over the course of one year to determine seed viability and presence of endophyte in seedlings. Viability of seed declined rapidly to be 10% 3 months after burial. Further decline in viability was less, so that 12 months after burial 4% of seeds were still viable. Endophyte viability also declined, from 58% infection of seedlings at the time of burial to 21% at 12 months. This was at a slower rate than the decline in seed viability and from what might have been predicted from seed storage experiments. Viability of seed buried at 10 cm was greater than that buried at 3 cm (e.g., means, 10% and 1% after 6 months, respectively). This has implications for cultivation practices before pasture establishment. Seed buried at Lincoln maintained higher viability than seed buried at Palmerston North (e.g., means, 6% and 4% after 6 months, respectively), which was associated with drier soil conditions at Lincoln. Survival of buried seed may therefore be of greater importance in summer-dry east coast regions, compared with moist west coast environments or in wet years. The significance of buried ryegrass seed will depend on the numbers involved, but after 12 months there were still viable seeds left in the soil and some of these were infected with endophyte. This is important for pastures sown with ryegrass that is free of endophyte or infected with a selected endophyte, and for slower establishing grass species such as tall fescue. Keywords: endophyte, endophyte survival, Lolium perenne, Neotyphodium lolii, perennial ryegrass, seed burial, seed survival

scholarly journals Determination of the toxic threshold of lolitrem B in cattle eating endophye-infected perennial ryegrass

2007 ◽  
Vol 13 ◽  
pp. 399-402
Author(s):  
L. Blythe ◽  
C. Estill ◽  
J. Males ◽  
A.M. Craig
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Clinical Signs ◽  
Positive Control ◽  
Control Group ◽  
Crossbred Cattle ◽  
Testing Laboratory ◽  
Neotyphodium Lolii ◽  
Lolitrem B

Perennial ryegrass (Lolium perenne) straw is used as a feed for livestock and horses. Some straw is infected with the endophyte, Neotyphodium lolii, which produces lolitrem tremorgens. Ingesting of the toxin produces clinical "ryegrass staggers." A 28 day feeding trail was conducted using 61 Black Angus, pure and crossbred cattle. The cattle were fed one of three levels of lolitrem B in chopped perennial ryegrass straw ranging from 0 ppb up to 3058 ppb. Four Japanese Wagyu crossbred cattle were fed chopped ryegrass straw containing 1400 ppb lolitrem B. The cattle were evaluated and scored twice a day for clinical signs of gait difficulties. Cattle consuming 1400 ppb lolitrem B did not show any overt clinical signs. After 14 days, 7 out of 15 cattle in the 1954 ppb lolitrem B group showed clinical signs of ataxia, stiffness, and tremors as seen in ryegrass staggers. All of the cattle in the positive control group of up to 3058 ppb lolitrem B with a 4 week mean of 2574 ppb developed clinical signs of staggers. None of the Wagyu cattle at 1400 ppb lolitrem B developed clinical signs. A dose response curve was developed based on the results of this study coupled with a prior study for use in the testing laboratory. Keywords: lolitrem B, perennial ryegrass, Lolium perenne, endophyte fungus, Neotyphodium lolii, cattle, threshold levels

The impact of endophyte on the health and productivity of sheep grazing ryegrass-based pastures

1999 ◽  
Vol 7 ◽  
pp. 11-17
Author(s):  
L.R. Fletcher ◽  
B.L. Sutherland ◽  
C.G. Fletcher
Keyword(s):  
Perennial Ryegrass ◽  
Growth Rates ◽  
Plasma Prolactin ◽  
Sheep Grazing ◽  
Wild Type ◽  
Lower Plasma ◽  
Lower Growth ◽  
Respiration Rates ◽  
Neotyphodium Lolii ◽  
The Impact

The health and production of sheep grazing perennial ryegrass with and without wild-type endophyte (Neotyphodium lolii) has been studied in several trials over a number of years. Lambs/ hoggets grazing predominantly perennial ryegrass swards with endophyte developed moderate to severe ryegrass staggers in summer and autumn, while those grazing endophyte-free ryegrass did not. Lambs/hoggets grazing ryegrass with endophyte also had more dags, lower growth rates, lower plasma prolactin levels, higher body temperatures and respiration rates under warm humid conditions. Most of these adverse responses were more severe in summer and autumn when endophyte toxin concentrations were highest. Many of these symptoms are similar to those described for the "autumn ill thrift" syndrome in New Zealand. Keywords: dags, endophyte, flystrike, growth rates, hyperthermia, Neotyphodium, perennial ryegrass, prolactin, ryegrass staggers, sheep

Genetic Diversity in the Perennial Ryegrass Fungal Endophyte Neotyphodium lolii

2004 ◽  
pp. 155-164 ◽  
Author(s):  
Eline van Zijll de Jong ◽  
Nathaniel R. Bannan ◽  
Jacqueline Batley ◽  
Kathryn M. Guthridge ◽  
German C. Spangenberg ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Perennial Ryegrass ◽  
Fungal Endophyte ◽  
Neotyphodium Lolii

scholarly journals Progress in breeding sheep for resistance to ryegrass staggers

2007 ◽  
Vol 13 ◽  
pp. 431-431
Author(s):  
C.A. Morris ◽  
N.C. Amyes
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Metabolic Disorder ◽  
Scoring System ◽  
Neotyphodium Lolii ◽  
High Heritability ◽  
Lolitrem B ◽  
Clinical Cases

Ryegrass Staggers (RGS) is predominantly a summer/autumn metabolic disorder of ruminants, caused by ingestion of the toxin lolitrem B. The toxin is produced by an endophyte (Neotyphodium lolii) found in perennial ryegrass (Lolium perenne). In clinical cases of RGS, animals experience neuromuscular uncoordination when under stress, e.g. when mustered by sheep dogs. Experiments with a standardised RGS scoring system show that resistance/susceptibility in sheep has a moderate/high heritability (0.37 ± 0.05). An AgResearch flock was established in 1993, with two lines bred for resistance (R) or susceptibility (S) to RGS. Annually, lambs are scored for susceptibility, when both lines graze together on high endophyte pastures, and are mustered by sheep dogs. In 2005 and 2006, 2% and 6.5% of R-line lambs, respectively, showed clinical staggers, compared with 94% and 91% of S-line lambs (P

Global Genetic Diversity of the Perennial Ryegrass Fungal Endophyte Neotyphodium lolii

Crop Science ◽  
2008 ◽  
Vol 48 (4) ◽  
pp. 1487-1501 ◽  
Author(s):  
Eline van Zijll de Jong ◽  
Mark P. Dobrowolski ◽  
Nathaniel R. Bannan ◽  
Alan V. Stewart ◽  
Kevin F. Smith ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Perennial Ryegrass ◽  
Fungal Endophyte ◽  
Neotyphodium Lolii

Regrowth of prairie grass (Bromus willdenowii Kunth) and perennial ryegrass (Lolium perenne L.) in response to temperature and defoliation

2000 ◽  
Vol 51 (5) ◽  
pp. 555 ◽  
Author(s):  
K. Slack ◽  
W. J. Fulkerson ◽  
J. M. Scott
Keyword(s):  
High Temperature ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Growth Rates ◽  
Water Soluble ◽  
The Other ◽  
Effect Of Temperature ◽  
Lolium Perenne L ◽  
Leaf Stage ◽  
Prairie Grass

This glasshouse study was undertaken to determine the effect of temperature and defoliation on the regrowth of prairie grass (Bromus willdenowii Kunth cv. Matua) in comparison with perennial ryegrass (Lolium perenne L. cv. Dobson). Individual plants of prairie grass and perennial ryegrass were grown in 2 mini-swards with one half as prairie grass and the other as ryegrass. From H0 (13 weeks after sowing) to the completion of the experiment at H3, one sward was maintained at a day/night temperature of 18/10˚C and the other at 25/15˚C. From H0 to H1, prairie grass was defoliated 4 times at the time taken to regrow 1 new leaf per tiller (1-leaf stage), 2 times at the 2-leaf stage, or once at the 4-leaf stage to 60, 90, or 120 mm stubble height. Similarly, ryegrass was defoliated 3 times at the 1- leaf stage, once at the 1-leaf stage then once at the 2-leaf stage, or once at the 3-leaf stage to 30, 60, or 90 mm stubble height. Plants were subsequently harvested at H1, H2, and H3, being the commencement, mid-point, and completion of the full regrowth cycle (4- and 3-leaf stage for prairie grass and ryegrass, respectively). Prairie grass was more adversely affected by frequent defoliation than ryegrass. The combination of high temperature and frequent defoliation reduced growth rates by 66 v. 54%, stubble dry matter (DM) by 50 v. 11%, root DM by 62 v. 45%, and stubble water-soluble carbohydrate (WSC) by 52 v. 21% for prairie grass and ryegrass, respectively. In contrast, ryegrass was more affected by defoliation height than prairie grass, particularly at the higher temperature. Close defoliation and high temperature reduced growth rate by 35 v. 25%, root DM by 18 v. 0%, and stubble WSC by 84% v. 36% for ryegrass and prairie grass, respectively. The number of tillers per plant was reduced by close defoliation, more so at the high temperature in ryegrass but not in prairie grass. Defoliating prairie grass to 90 mm stubble height at the 4-leaf per tiller stage compared with the 1-leaf per tiller led to maximum restoration of stubble WSC reserves as well as maximising leaf and root growth. The higher stubble WSC and greater root DM of prairie grass, together with its ability to maintain growth rates and tillering under high temperature, are attributes which explain why prairie grass appears to be more productive and persistent than ryegrass in a subtropical environment.

scholarly journals Modelling Carbon Fluxes as an Aid to Understanding Perennial Ryegrass (Lolium perenne) Root Dynamics

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 236
Author(s):  
Arif Robin ◽  
Louis Irving ◽  
Edith Khaembah ◽  
Cory Matthew
Keyword(s):  
Root Growth ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Growth Rates ◽  
Plant Performance ◽  
Seasonal Effects ◽  
Cultivar Differences ◽  
Root Turnover ◽  
Root Dynamics ◽  
Maintenance Respiration

Despite the importance of roots in determining plant performance, the factors controlling their development and longevity remain poorly understood. Grass morphology is based on repeating units called phytomers, with each capable of producing one leaf, one daughter tiller, and one or more roots. We developed a phytomer-based understanding of root birth, growth and senescence in Lolium perenne, using a modeling approach to explore seasonal effects on root turnover dynamics, and to explore cultivar differences in these processes. Similar to leaves, roots exhibit a clear progression from initiation, growing for approximately seven phyllochrons, with growth rates strongly influenced by environmental conditions. In spring, the phyllochron decreased over the experiment, while it increased in autumn. In spring, C availability exceeding maintenance respiratory requirements allowed root growth at each phytomer position, with a 70/30 split between maintenance and growth. Under C-deficient conditions in autumn, this split was approximately 80/20, with growth limited to younger phytomer positions, while older roots were more susceptible to starvation-induced senescence due to their high C requirements for maintenance respiration.

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