Endophyte infection effects on stomatal conductance, osmotic adjustment and drought recovery of tall fescue

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.

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Germination rate and seedling vigour of tall fescue as affected by endophyte status and seed density

NZGA: Research and Practice Series ◽

10.33584/rps.13.2006.3109 ◽

2007 ◽

Vol 13 ◽

pp. 271-274

Author(s):

H.T. Owens ◽

C.H. Finneseth ◽

T.M. Tillery ◽

T.D. Phillips

Keyword(s):

Tall Fescue ◽

Seed Quality ◽

Germination Rate ◽

Storage Conditions ◽

Seed Density ◽

Seedling Vigour ◽

Density Fractions ◽

Endophyte Infection ◽

Early Germination ◽

Air Column

Forage grass seed quality is influenced by plant genetics as well as seed density, storage conditions, age of seed, and endophyte infection status. We used eight seed lots of tall fescue (three cultivars, with natural endophytes, endophyte-free, or novel endophyte) to test the effect of seed density on germination and seedling vigour. Seed lots were separated into nine density fractions using a cylinder air column. Thousand seed weight values were determined. Three runs of four replications of plots consisting of 25 seeds of each entry were seeded in greenhouse experiments to determine seedling mass at 8 weeks after planting. Early germination counts as well as laboratory germination tests indicated significant differences among weight classes in speed of germination as well as seedling vigour. The lightest fraction of seed clearly contained inferior seed, but higher density seed lots tended to have better germination and seedling vigour than lower density ones. Keywords: seed density, seedling vigour, germination, tall fescue, endophyte

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Body weight gain and voluntary feed intake in meat goat does fed endophyte-infected and endophyte-free tall fescue seed

NZGA: Research and Practice Series ◽

10.33584/rps.13.2006.3115 ◽

2007 ◽

Vol 13 ◽

pp. 427-429

Author(s):

R. Browning ◽

J.R. Author ◽

B. Donnelly ◽

T. Payton ◽

P. Pandya ◽

...

Keyword(s):

United States ◽

Body Weight ◽

Feed Intake ◽

Tall Fescue ◽

Body Weight Gain ◽

Southeastern United States ◽

Voluntary Feed Intake ◽

Endophyte Infection ◽

States Data ◽

Meat Goat

Tall fescue is the primary pasture forage offered to goats in the southeastern United States. Data on how tall fescue endophyte (Neotyphodium coenophialum) affects meat goat performance are lacking. In three summers, yearling does were fed diets containing tall fescue seed to assess the effect of endophyte infection on goat growth and feed intake. In 2004 and 2005, does were fed endophyte-infected (EI) or endophyte-free (EF) tall fescue seeds added to the diets for 10 wk. Feed refusals were weighed daily. The EI diet reduced (P

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Correlation of Heat and Cold Tolerance in Iranian Tall Fescue Ecotypes with Reactive Oxygen Species Scavenging and Osmotic Adjustment

HortScience ◽

10.21273/hortsci13088-18 ◽

2018 ◽

Vol 53 (7) ◽

pp. 1062-1068

Author(s):

Mohamad-Hossein Sheikh-Mohamadi ◽

Nematollah Etemadi ◽

Mostafa Arab

Keyword(s):

Cold Stress ◽

Tall Fescue ◽

Osmotic Adjustment ◽

Festuca Arundinacea ◽

Antioxidant Activities ◽

Control Group ◽

Excessive Heat ◽

Total Nonstructural Carbohydrates ◽

Heat And Cold Stress

Excessive heat or cold usually reduces the growth and quality of turfgrass. Genetic variations along with efficient biochemical and physiological mechanisms can diversify the tolerance to heat and cold. This study examined the effects of heat and cold stress on several biochemical and physiological parameters in Iranian tall fescue ecotypes (Festuca arundinacea L.). The control group of plants was maintained under optimal temperatures, whereas other groups were exposed to heat or cold in a growth chamber. The experiment was designed as a split plot, with stress treatments as the main plots and ecotypes as subplots. Physiologically and biochemically, the results revealed that three ecotypes (‘FA1’, ‘FA3’, and ‘FA5’) of the eight ecotypes examined in this study had better abilities to survive the simulated heat and cold stress. Better tolerance to heat and cold in the ‘FA1’, ‘FA3’, and ‘FA5’ ecotypes were probably due to higher levels of enzymatic and nonenzymatic antioxidant activities, maintenance of lower levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2), higher levels of proline and total nonstructural carbohydrates (TNC), along with a more efficient osmotic adjustment. Diamine oxidase (DAO) and polyamine oxidase (PAO) activities increased significantly in ‘FA1’, ‘FA3’, and ‘FA5’ ecotypes. In summary, the strength of tolerance among ecotypes can be ranked as ‘FA1’ > ‘FA3’ > ‘FA5’ > ‘FA2’ > ‘FA6’ > ‘FA4’ > ‘FA7’ > ‘FA8’ under heat stress and ‘FA5’> ‘FA1’ > ‘FA3’ > ‘FA2’ > ‘FA4’ > ‘FA6’ > ‘FA7’ > ‘FA8’ under cold stress.

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173 The effects of Fescue EMTTM Mineral Defense on stocker heifer growth while grazing tall fescue

Journal of Animal Science ◽

10.1093/jas/skz053.135 ◽

2019 ◽

Vol 97 (Supplement_1) ◽

pp. 60-60

Author(s):

Anna R Taylor ◽

Randy Dew ◽

Ken Bryan ◽

J Nathan Pike ◽

T Ryan Lock

Keyword(s):

Weight Gain ◽

Reproductive Performance ◽

Tall Fescue ◽

Repeated Measures ◽

Animal Nutrition ◽

Forage Availability ◽

Randomized Design ◽

Endophyte Infection ◽

Completely Randomized Design ◽

Over Time

Abstract Previous research demonstrates grazing tall fescue can decrease reproductive performance and weight gain in cattle. The objective of this study was to evaluate Fescue EMTTM Mineral Defense (Cargill Animal Nutrition, Minneapolis, MN) on summer weight gain in cattle grazing tall fescue pastures in SW Missouri. Heifers (n = 120; initial BW = 236 ± 2.5 kg) were stratified by weight to replicated tall fescue pastures to either a control mineral treatment or Fescue EMT™ Mineral Defense treatment. Forage availability was estimated weekly by ultrasonic sensor. Pasture samples were collected every 21 d and analyzed for ergovaline concentrations. Heifer weights and blood prolactin were measured throughout the trial. Average daily mineral consumption was calculated by mineral offered less residual. Data were analyzed on a pen-mean basis as a completely randomized design using JMP with 6 pens/ treatment and 10 heifers/pen. Prolactin was analyzed as Repeated Measures in JMP. Initial weights between treatments were not different (P > 0.05). Endophyte infection measured 75% or greater in all pastures. No differences were detected in pasture ergovaline (149 ± 19 µg/kg) or pasture availability (2,600 ± 150 kg/ha) between treatments (P > 0.20 at each sampling). Heifer ADG consuming Fescue EMT™ Mineral Defense compared to control mineral was greater at 0.28 kg versus 0.22 kg resulting in total gains of 21.8 kg versus 16.6 kg, respectively (P < 0.05). However, blood prolactin numerically decreased over time in both treatments. Results from this trial demonstrate a 31% improvement in weight gain for cattle consuming Fescue EMTTM Mineral Defense compared with cattle consuming a control mineral while grazing toxic tall fescue.

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Relationship between Level of Endophyte Infection and Cattle Gains on Tall Fescue

jpa ◽

10.2134/jpa1989.0147 ◽

1989 ◽

Vol 2 (2) ◽

pp. 147-151 ◽

Cited By ~ 36

Author(s):

R. J. Crawford ◽

J. R. Forwood ◽

R. L. Belyea ◽

G. B. Garner

Keyword(s):

Tall Fescue ◽

Endophyte Infection

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Ecophysiological Responses of Tall Fescue Genotypes to Fungal Endophyte Infection and Elevated Temperature and Precipitation

CSA News ◽

10.2134/csa2016-61-3-3 ◽

2016 ◽

Vol 61 (3) ◽

pp. 10-11

Author(s):

Kaine Korzekwa

Keyword(s):

Elevated Temperature ◽

Tall Fescue ◽

Fungal Endophyte ◽

Temperature And Precipitation ◽

Endophyte Infection ◽

Ecophysiological Responses

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Why Measure Osmotic Adjustment?

Functional Plant Biology ◽

10.1071/pp9880717 ◽

1988 ◽

Vol 15 (6) ◽

pp. 717 ◽

Cited By ~ 112

Author(s):

R Munns

Keyword(s):

Cell Wall ◽

Stomatal Conductance ◽

Osmotic Adjustment ◽

Cell Expansion ◽

Control Cell ◽

Growth Yield ◽

Future Research ◽

Saline Soils ◽

Cell Wall Synthesis ◽

Adaptation To Drought

Osmotic adjustment (erroneously called 'osmoregulation') is generally regarded as an important adaptation to drought or salinity. Because it helps to maintain turgor and cell volume, it is often thought to promote growth, yield, or survival, of plants in dry or saline soils. However, a physiological rationale for such views is lacking. Osmotic adjustment itself cannot promote growth; the solutes which account for it must be diverted from essential processes such as protein and cell wall synthesis. Further, it now appears that turgor does not control cell expansion or stomatal conductance. Thus, osmotic adjustment cannot affect yields except via other processes, the controls of which are almost entirely unexplored. Future research in this area should test hypotheses, rather than merely measure osmotic adjustment.

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