Ash, carbon isotope discrimination, and silicon as estimators of transpiration efficiency in crested wheatgrass

Mayland, H.F. and Johnson, D.A. and Asay, K.H. and Read, J.J. (1993) Ash, carbon isotope discrimination, and silicon as estimators of transpiration efficiency in crested wheatgrass. Australian Journal of Plant Physiology. 20:361-369.

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Abstract

Breeding and selection for higher transpiration efficiency (W) has been hampered by tedious and costly
methodology. Rapid and less costly methods are needed for screening W in plant improvement
programmes. We report the relationship of ash, silicon (Si) concentration, and Si uptake to W in
crested wheatgrass (Agropyron desertorum [Fischer ex Link] Schultes), an important C3 range grass in
western North America. Clones of crested wheatgrass were grown under three water levels in a field
rainout shelter and as potted plants under two water levels in the field and greenhouse. Ash and Si
concentrations were compared to previously determined values of shoot mass, transpiration, W, and
carbon isotope discrimination (A). Ash and Si concentrations were not consistently related to ∆ and W
across all environments; however, ash concentration was positively correlated with ∆ (r=0•69**,
df = 22) and negatively correlated with W (r= -0•61**, df=22) in the well-watered field environment.
Across all environments and studies, the ranges in the coefficients of variation (CV, %) for clonal
means were: W, 4-15; ∆, 1-4; ash concentration, 6-14; Si concentration, 13-30; and Si uptake, 21-33.
The generally lower CV for W, ∆, and ash concentration suggest that these traits were more repeatable
than Si concentration or uptake. Although a consistent relationship was not observed between Si and
W and between ash and W, the correlations of ash and W from the well-watered field environment
were encouraging. In view of the low cost for ash analysis, we conclude that further research is needed
to evaluate the potential of ash as a criterion in selecting for improved W, particularly during the
early phases of a breeding programme when large populations are usually involved. Later selections
could be based on the more precise and accurate, but costly, ∆ analysis.

Item Type:	Article
NWISRL Publication Number:	0803
Subjects:	Irrigated crops > Grass forage > Chemistry Research methodology Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	01 Dec 2016 21:37
Item ID:	600
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/600