Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Germination of Seeds of Big and Bottlebrush Squirreltail

James A. Young, Charlie D. Clements and Tom Jones
Journal of Range Management
Vol. 56, No. 3 (May, 2003), pp. 277-281
DOI: 10.2307/4003819
Stable URL: http://www.jstor.org/stable/4003819
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Germination of Seeds of Big and Bottlebrush Squirreltail
Preview not available

Abstract

Bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey] and big squirreltail [E. multisetus (J. G. Smith) Burtt Davy] are short-lived perennial bunchgrasses found on rangelands from the Pacific Coast to the Great Plains and from Canada to Mexico. They are highly variable species with several subspecies described for bottlebrush squirreltail. In many rangeland communities, bottlebrush squirreltail is the transitional dominant native grass in secondary successional communities. There is considerable interest in using squirreltail species in rangeland restoration seedings, but problems with seed collection (disarticulating rachis) have kept seed prices very high. Recently, grass geneticists have begun to develop lines of squirreltail for release as pre-varietal germplasm. Our purpose was to compare the germination at a wide range of constant or alternating temperatures of squirreltail seeds from developmental lines and material collected from native stands. Big and bottlebrush squirreltail seeds (caryopses) germinated over a wide range of temperatures. Seeds of bottlebrush squirreltail produced from the same stand in 3 different years had remarkably similar germination temperature profiles. The greatest variation in germination among accessions occurred at very cold and cold categories of seedbed temperatures. These differences may be very significant in the establishment of seedlings in the field. There was no one temperature regime that always supported optimum germination for all of the squirreltail accessions tested. The regimes most frequently supporting optimum germination were 15/20 and 15/25° C. The seeds of big and bottlebrush squirreltail tested do not have the ecological amplitude of seeds of the competitive exotic weed cheatgrass (Bromus tectorum L.), but they come close. /// "Bottlebrush squirreltail" [Elymus elymoides (Raf.) Swezey] y "Big squirreltail" [E. multisetus (J. G. Smith) Burtt Davy] son zacates amacollados perennes de vida corta que se encuentran en los pastizales, desde la Costa del Pacifico hasta las Grandes Planicies y desde Canadá hasta México. Estas especies son altamente variables con varias subespecies descritas para "Bottlebrush squirreltail". En muchas comunidades de pastizal, en sucesión secundaria, el "Bottlebrush squirreltail" es el zacate nativo transicional dominate. Hay un considerable interés en usar especies de "Squirreltail" en siembras para restaurar pastizales, pero problemas con la colección de semilla (desarticulación del raquis) han mantenido los precios de la semilla muy altos. Recientemente los genetistas de pastos han iniciado el desarrollo de líneas de "Squirreltail" para liberarlas como germoplasma pre-varietal. Nuestro propósito fue comparar la germinación de semillas de las líneas de "Squirreltail" en desarrollo y material colectado de poblaciones nativas bajo un amplio rango de temperaturas constantes o alternadas. Las semillas (cariposides) de "Big squirreltail" y "Bottlebrush squirreltail" germinaron en un amplio rango de temperaturas. Semillas de "Bottlebrush squirreltail" producidas en la misma población, pero en tres diferentes años, tuvieron perfiles de temperatura de germinación remarcablemente similares. La mayor variación en germinación entre las accesiones evaluadas ocurrió en las categorías de temperatura de la cama de siembra de frias y muy fria. Estas diferencias pueden ser muy significativas en el establecimiento de plántulas en el campo. No hubo un régimen de temperatura que mantuviera siempre la germinación óptima para todas las accesiones de "Squirreltail" evaluadas. Los regímenes que más frecuentemente mantuvieron la geminación óptima fueron 15/20 y 15/25° C. Las semillas evaluadas de "Big squirreltail" y "Bottlebrush squirreltail" no tienen la amplitud ecológica de las semillas de la maleza exótica "Cheatgrass" (Bromus tectorum L.), sin embargo ellas están muy cerca.

Page Thumbnails

  • Thumbnail: Page 
277
    277
  • Thumbnail: Page 
278
    278
  • Thumbnail: Page 
279
    279
  • Thumbnail: Page 
280
    280
  • Thumbnail: Page 
281
    281