Characterization of crown node elevation in Panicoid grasses.

Tischler, C.R.
Voigt, P.W.
Rangeland Ecology & Management / Journal of Range Management Archives
Publication Year: 
In Panicoid grasses, elevation of the crown node above the soil surface caused by excessive subcoleoptile internode elongation is detrimental to seedling establishment. We describe a technique to screen grass seedlings for excessive crown node elevation. Seed of 11 perennial grass cultivars were germinated and grown in a plywood box 1.2 X 1.2 X 1.2 m at an irradiance of 1.5 micromole m(-2) sec(-1) at 30 degrees C. A subset of 8 grasses were grown similarly but at an irradiance of 0.75 micromole m(-2) sec(-1). Elevation of crown nodes above the growth media and shoot length (from crown node to leaf tip) were measured 7 days after planting. The crown nodes of 4 Eragrostis species were not elevated above the soil surface, while other species had mean crown node elevations of 1 cm or more. Relative ranking of crown node elevation was similar for a species within each light level, but response to change in light intensity was not consistent across species. Sideoats grama (Bouteloua curtipendula (Michx.) Torr.), blue grama (Bouteloua gracilis (H.B.K. Lag. ex Steud.)), and kleingrass (Panicum coloratum L.) exhibited significant crown node elevation in this system. Estimates of genetic variation based on comparison of apomictic and sexual grasses within this group suggest that substantial genetic variation exists for excessive subcoleoptile internode elongation and that progress by selection for lower crown node placement should be possible in most of the grasses studied. This system allows characterization of grasses for extent of crown node elevation and is being used in a recurrent selection protocol to select for lower crown node placement.
Document Type: 
Journal Issue/Article
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Rangeland Ecology & Management (formerly the Journal of Range Management) serves as a forum for the presentation and discussion of facts, ideas, and philosophies pertaining to the study, management, ecology, and use of rangelands and their resources. The journal is peer-reviewed and provides international exchange of scholarly research and information among persons interested in rangelands. The Global Rangelands collection includes REM content up to 5 years from the current year. More recent content is available by subscription from BioOne and the Society for Range Management, and may be available at your local university library.
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