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ARS Home » Research » Publications at this Location » Publication #191915
Title: LIMITS TO PRODUCTION

Author
item Belesky, David
item WEST, CHARLES - UNIVERSITY OF ARKANSAS

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/10/2005
Publication Date: 12/31/2005
Citation: Belesky, D.P., West, C. 2005. Limits to Production. Chapter 4. In Tall fescue on-line monograph. H.A. Fribourg and D.B. Hannaway (eds.) Oregon State University, Forage Information System.

Interpretive Summary:

Technical Abstract: Agronomically important grasses, including tall fescue and perennial ryegrass, form symbiotic associations with fungal endophytes. In general, endophyte infection frequencies seem more variable in natural ecosystems than in agroecosystem situations, suggesting that expression and benefits attributable to infection depend on the resource environment in which the host endophyte complex was formed and the conditions under which the association is grown. Emerging evidence suggests that expression is not always mutualistic or beneficial to the host in terms of productivity and persistence in resource-limited environments. Abiotic factors associated with regional and local climate influence the host endophyte grazer complex, and can do so at many levels. For example, factors could interact with: * Host endophyte genotype (plant and fungal genome expression when growing as symbionts, with expression ranging from mutualism to antagonism; components could include native and novel non ergogenic endophytes, and plant composition * Host endophyte genotype x soil resources, such as mineral nutrients, pH, water * Host endophyte genotype x grazer genotype, e.g., breed, Bos taurus compared to B. indicus, and within breed variation. All of the interactions are likely to be affected by factors associated with management of agroecosystems and might not always be expressed in the same manner or to the same degree. Endophyte infection could provide host plants with means to grow and persist under conditions of marginal water and nutrient supply, whereas plants lacking endophyte might be at a competitive and adaptive disadvantage. We present current understanding of host plant endophyte interactions with emphasis on tall fescue responses to abiotic features of the environment.