Genotype and water limitation effects on transpiration efficiency in sorghum

Mortlock, M. Y. and Hammer, G. L. (1999) Genotype and water limitation effects on transpiration efficiency in sorghum. Journal of Crop Production, 2 2: 265-286.

Author Mortlock, M. Y.
Hammer, G. L.
Title Genotype and water limitation effects on transpiration efficiency in sorghum
Journal name Journal of Crop Production   Check publisher's open access policy
ISSN 1092-678X
Publication date 1999-01
Sub-type Article (original research)
Volume 2
Issue 2
Start page 265
End page 286
Total pages 22
Place of publication New York, USA
Publisher Haworth Press, USA
Collection year 1999
Language eng
Subject C1
300203 Plant Improvement (Selection, Breeding and Genetic Engineering)
620100 Field Crops
Abstract Sorghum is grown in many parts of the semi-arid tropics in environments where water limitation is common. Recent studies have identified genetic variation in transpiration efficiency (TE) in sorghum under well-watered conditions. Crop simulation studies suggest that improvement in TE in sorghum could have considerable payoff in many water-limited environments. The objectives of this study were to examine the variation in TE for a range of sorghum genotypes grown under well watered and water limited conditions, and to seek selection indices for this trait by measuring a range of associated physiological and morphological attributes. A glasshouse study was conducted with 17 genotypes grown under well-watered (WW) or waterlimited (WL) conditions. Plants were grown in mini-lysimeters and water use and biomass production were measured. A range of other attributes were measured at plant and leaf level. Genotypes varied significantly in TE (highest about 50% greater than lowest) and TE was about 10% greater under WL. There was no interaction among genotype and water treatments. TE correlated well with transpiration per unit leaf area, which is a plant scale index of conductance. Leaf level measurements supported the association of TE with conductance. The best indicators of variation in TE were leaf C concentration and leaf ash, which offer promise as an avenue for development of a selection index. The mechanism underlying this association, however, remains unclear. Before TE can be used actively in a breeding program, field studies are required to confirm these findings from glasshouse studies and more robust selection indices are needed.
Keyword Ash Content
Carbon isotope discrimination
Leaf C concentration
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
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Created: Tue, 10 Jun 2008, 13:43:50 EST