scholarly journals Community and ecosystem consequences of endophyte symbiosis with tall fescue

2007 ◽  
Vol 13 ◽  
pp. 19-35
Author(s):  
Jennifer Rudgers ◽  
Keith Clay
Keyword(s):  
Tall Fescue ◽  
Plant Competition ◽  
Trophic Levels ◽  
Infection Frequency ◽  
Neotyphodium Coenophialum ◽  
Lolium Arundinaceum ◽  
Infection Dynamics ◽  
Eastern Usa ◽  
Plant Herbivore ◽  
Herbivore Pressure

We have investigated community and ecosystem consequences of endophyte symbiosis with tall fescue over the past 13 years. Lolium arundinaceum is the most abundant plant in the eastern USA, and most is infected by the wild-type endophyte Neotyphodium coenophialum in Kentucky 31. We established two large experimental grasslands (in 1994 and in 2000) with E+ and E- seed sown in each on recently ploughed herbaceous vegetation. Other plant species established naturally by seed or vegetative fragments. No other treatments were applied and plots were subject to natural biotic and abiotic variation. A third experiment examined ecological influences on endophyte infection dynamics starting from an intermediate infection frequency. We found wide-ranging consequences of the endophyte from significant effects on soil feedback and decomposition rates, to plant-plant competition, diversity, productivity, invasibility and succession, to plant-herbivore interactions and energy flow to higher trophic levels. Further, we found that herbivore pressure caused rapid increases in infection frequency. Our results suggest that endophyte symbiosis in tall fescue can have a transforming effect on ecological systems. Keywords: Lolium arundinaceum, Neotyphodium coenophialum, soil, competition, herbivory, trophc interactions, predators, MaxQ endophyte

scholarly journals Interactions between plant genome size, nutrients and herbivory by rabbits, molluscs and insects on a temperate grassland

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182619 ◽  
Author(s):  
Maïté S. Guignard ◽  
Michael J. Crawley ◽  
Dasha Kovalenko ◽  
Richard A. Nichols ◽  
Mark Trimmer ◽  
...  
Keyword(s):  
Plant Species ◽  
Plant Competition ◽  
Plant Genome ◽  
Total Biomass ◽  
Nutrient Inputs ◽  
Nutrient Quality ◽  
Path Analyses ◽  
Plant Herbivore ◽  
Herbivore Pressure ◽  
The Impact

Angiosperm genome sizes (GS) vary ca 2400-fold. Recent research has shown that GS influences plant abundance, and plant competition. There are also tantalizing reports that herbivores may select plants as food dependent on their GS. To test the hypothesis that GS plays a role in shaping plant communities under herbivore pressure, we exploit a grassland experiment that has experimentally excluded herbivores and applied nutrient over 8 years. Using phylogenetically informed statistical models and path analyses, we show that under rabbit grazing, plant species with small GS generated the most biomass. By contrast, on mollusc and insect-grazed plots, it was the plant species with larger GS that increased in biomass. GS was also shown to influence plant community properties (e.g. competitive strategy, total biomass) although the impact varied between different herbivore guilds (i.e. rabbits versus invertebrates) and nutrient inputs. Overall, we demonstrate that GS plays a role in influencing plant–herbivore interactions, and suggest potential reasons for this response, which include the impact of GS on a plant's response to different herbivore guilds, and on a plant's nutrient quality. The inclusion of GS in ecological models has the potential to expand our understanding of plant productivity and community ecology under nutrient and herbivore stress.

scholarly journals Effects of multiple climate change factors on the tall fescue-fungal endophyte symbiosis: infection frequency and tissue chemistry

2010 ◽  
Vol 189 (3) ◽  
pp. 797-805 ◽  
Author(s):  
Glade B. Brosi ◽  
Rebecca L. McCulley ◽  
Lowell P. Bush ◽  
Jim A. Nelson ◽  
Aimée T. Classen ◽  
...  
Keyword(s):  
Climate Change ◽  
Tall Fescue ◽  
Fungal Endophyte ◽  
Infection Frequency ◽  
Change Factors ◽  
Tissue Chemistry

scholarly journals Latitudinal variation in seed predation correlates with latitudinal variation in seed defensive and nutritional traits in a widespread oak species

2019 ◽  
Vol 125 (6) ◽  
pp. 881-890 ◽  
Author(s):  
Xoaquín Moreira ◽  
Luis Abdala-Roberts ◽  
Hans Henrik Bruun ◽  
Felisa Covelo ◽  
Pieter De Frenne ◽  
...  
Keyword(s):  
Seed Predation ◽  
Plant Traits ◽  
Climatic Factors ◽  
Latitudinal Gradients ◽  
Latitudinal Variation ◽  
Seed Traits ◽  
Plant Defences ◽  
Herbivore Interactions ◽  
Plant Herbivore ◽  
Herbivore Pressure

Abstract Background and Aims Classic theory on geographical gradients in plant–herbivore interactions assumes that herbivore pressure and plant defences increase towards warmer and more stable climates found at lower latitudes. However, the generality of these expectations has been recently called into question by conflicting empirical evidence. One possible explanation for this ambiguity is that most studies have reported on patterns of either herbivory or plant defences whereas few have measured both, thus preventing a full understanding of the implications of observed patterns for plant–herbivore interactions. In addition, studies have typically not measured climatic factors affecting plant–herbivore interactions, despite their expected influence on plant and herbivore traits. Methods Here we tested for latitudinal variation in insect seed predation and seed traits putatively associated with insect attack across 36 Quercus robur populations distributed along a 20° latitudinal gradient. We then further investigated the associations between climatic factors, seed traits and seed predation to test for climate-based mechanisms of latitudinal variation in seed predation. Key Results We found strong but contrasting latitudinal clines in seed predation and seed traits, whereby seed predation increased whereas seed phenolics and phosphorus decreased towards lower latitudes. We also found a strong direct association between temperature and seed predation, with the latter increasing towards warmer climates. In addition, temperature was negatively associated with seed traits, with populations at warmer sites having lower levels of total phenolics and phosphorus. In turn, these negative associations between temperature and seed traits led to a positive indirect association between temperature and seed predation. Conclusions These results help unravel how plant–herbivore interactions play out along latitudinal gradients and expose the role of climate in driving these outcomes through its dual effects on plant defences and herbivores. Accordingly, this emphasizes the need to account for abiotic variation while testing concurrently for latitudinal variation in plant traits and herbivore pressure.

Whole-crop triticale silage for dairy cows grazing perennial ryegrass (Lolium perenne) or tall fescue (Lolium arundinaceum) pastures in small-scale dairy systems during the dry season in the highlands of Mexico

2020 ◽  
Vol 52 (4) ◽  
pp. 1903-1910
Author(s):  
Felipe de Jesús González-Alcántara ◽  
Julieta Gertrudis Estrada-Flores ◽  
Ernesto Morales-Almaraz ◽  
Felipe López-González ◽  
Aida Gómez-Miranda ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Dry Season ◽  
Small Scale ◽  
Lolium Arundinaceum ◽  
Dairy Systems ◽  
Small Scale Dairy

scholarly journals Biological Control of Bipolaris sorokiniana on Tall Fescue by Stenotrophomonas maltophilia Strain C3

1999 ◽  
Vol 89 (9) ◽  
pp. 817-822 ◽  
Author(s):  
Z. Zhang ◽  
G. Y. Yuen
Keyword(s):  
Tall Fescue ◽  
Leaf Spot ◽  
Stenotrophomonas Maltophilia ◽  
Field Experiments ◽  
Bipolaris Sorokiniana ◽  
Colloidal Chitin ◽  
Growth Chamber ◽  
Complete Suppression ◽  
Infection Frequency ◽  
Leaf Surfaces

Stenotrophomonas maltophilia strain C3 was evaluated for control of leaf spot on tall fescue (Festuca arundinacea) caused by Bipolaris sorokiniana. In growth chamber experiments, C3 inhibited conidial germination on leaf surfaces and reduced lesion frequency and percent diseased leaf area compared with nontreated controls. The amount of leaf spot suppression was related to the C3 dose applied. The highest dose tested, 109 CFU/ml, prevented nearly all B. sorokiniana conidia from germinating on treated leaf surfaces and provided nearly complete suppression of lesion development. When colloidal chitin was added to C3 cell suspensions of 107 or 108 CFU/ml, biocontrol efficacy was significantly increased over C3 applied alone, whereas addition of chitin to a C3 cell suspension of 109 CFU/ml had no effect. In field experiments, application of C3 to tall fescue turf resulted in significant reductions in infection frequency and disease severity compared with nontreated controls. Strain C3 applied at 109 CFU/ml was more effective than C3 applied at 107 CFU/ml, and amendment of the lower dose with colloidal chitin enhanced its efficacy. Populations sizes of C3 established on foliage in a growth chamber and in the field were directly related to dose applied. Chitin amendments did not affect C3 population size.

Response of Pratylenchus spp. in tall fescue infected with different strains of the fungal endophyte Neotyphodium coenophialum

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Patricia Timper ◽  
Roger N. Gates ◽  
Joe H. Bouton
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Ergot Alkaloids ◽  
Nematode Resistance ◽  
Fungal Endophyte ◽  
Parasitic Nematodes ◽  
Small Subset ◽  
Neotyphodium Coenophialum ◽  
Different Strains ◽  
Endemic Strain

Abstract The presence of the fungal endophyte Neotyphodium coenophialum in tall fescue (Festuca arundinacea) confers resistance to some plant-parasitic nematodes but also results in the production of ergot alkaloids. Recently, new strains of N. coenophialum have been isolated from wild tall fescue and artificially inoculated into elite tall fescue cultivars. These strains produce low to nil levels of ergot alkaloids and are referred to as non-ergot strains. Our objective was to determine whether non-ergot strains of the endophyte confer the same level of resistance to Pratylenchus spp. as the endemic strain in tall fescue. In a glasshouse experiment, nematode resistance was compared in two fescue cultivars (Jesup and Georgia 5) infected with either the endemic strain (E+), or two non-ergot strains, AR542 and AR584. An additional non-ergot strain, AR514, was tested only in cv. Jesup. Cultivars Georgia 5 and Jesup without endophytes (E−) were used as controls. The endophtye status of the plants was confirmed and then three plants per cultivar/endophyte combination were transplanted into 10 cm square pots. The pots were inoculated with a mixed culture of Pratylenchus zeae and P. scribneri in the first trial and a pure culture of P. scribneri in the second trial of the experiment. After 8 weeks, the number of nematodes within the roots from each pot was determined. Numbers of Pratylenchus spp. in either cv. Georgia 5 or cv. Jesup containing the non-ergot strain AR542 were not different from numbers in E− plants. AR514 also did not confer resistance to the nematodes in cv. Jesup. By contrast, the non-ergot strain AR584 appears to confer resistance to Pratylenchus spp. in cv. Georgia 5, but not in cv. Jesup; however, the level of resistance in cv. Georgia 5 was less than the resistance conferred by the endemic endophyte. Genetic differences between the two tall fescue cultivars may affect growth of the endophyte or production of a nematode toxin or deterrent by the endophyte. As only a small subset of endophyte strains has been tested, we are screening additional non-ergot strains for resistance to P. scribneri.

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