Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Drought resistance, water-use efficiency, and yield potential—are they compatible, dissonant, or mutually exclusive?

Drought resistance, water-use efficiency, and yield potential—are they compatible, dissonant, or... This presentation is a concept review paper dealing with a central dilemma in understanding, designing, and acting upon crop plant improvement programs for drought conditions. The association among yield potential (YP), drought resistance (DR), and water-use efficiency (WUE) is often misunderstood, which in turn can lead to conceptual oversight and wrong decisions in implementing breeding programs for drought-prone environments. Although high YP is the target of most crop breeding programs, it might not be compatible with superior DR. On the other hand, high YP can contribute to yield in moderate stress environments. Plant production in water-limited environments is very often affected by constitutive plant traits that allow maintenance of a high plant water status (dehydration avoidance). Osmotic adjustment (OA) is a major cellular stress adaptive response in certain crop plants that enhances dehydration avoidance and supports yield under stress. Despite past voiced speculations, there is no proof that OA entails a cost in terms of reduced YP. WUE for yield is often equated in a simplistic manner with DR. The large accumulation of knowledge on crop WUE as derived from research on carbon isotope discrimination allows some conclusions on the relations between WUE on the one hand, and DR and YP on the other, to be made. Briefly, apparent genotypic variations in WUE are normally expressed mainly due to variations in water use (WU; the denominator). Reduced WU, which is reflected in higher WUE, is generally achieved by plant traits and environmental responses that reduce YP. Improved WUE on the basis of reduced WU is expressed in improved yield under water-limited conditions only when there is need to balance crop water use against a limited and known soil moisture reserve. However, under most dryland situations where crops depend on unpredictable seasonal rainfall, the maximisation of soil moisture use is a crucial component of drought resistance (avoidance), which is generally expressed in lower WUE. It is concluded that the effect of a single ‘drought adaptive’ gene on crop performance in water-limited environments can be assessed only when the whole system is considered in terms of YP, DR, and WUE. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Crop and Pasture Science CSIRO Publishing

Drought resistance, water-use efficiency, and yield potential—are they compatible, dissonant, or mutually exclusive?

Crop and Pasture Science , Volume 56 (11) – Nov 29, 2005

Loading next page...
 
/lp/csiro-publishing/drought-resistance-water-use-efficiency-and-yield-potential-are-they-ybmCu0oaVz

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
CSIRO Publishing
Copyright
CSIRO
ISSN
1836-0947
eISSN
1836-5795
DOI
10.1071/AR05069
Publisher site
See Article on Publisher Site

Abstract

This presentation is a concept review paper dealing with a central dilemma in understanding, designing, and acting upon crop plant improvement programs for drought conditions. The association among yield potential (YP), drought resistance (DR), and water-use efficiency (WUE) is often misunderstood, which in turn can lead to conceptual oversight and wrong decisions in implementing breeding programs for drought-prone environments. Although high YP is the target of most crop breeding programs, it might not be compatible with superior DR. On the other hand, high YP can contribute to yield in moderate stress environments. Plant production in water-limited environments is very often affected by constitutive plant traits that allow maintenance of a high plant water status (dehydration avoidance). Osmotic adjustment (OA) is a major cellular stress adaptive response in certain crop plants that enhances dehydration avoidance and supports yield under stress. Despite past voiced speculations, there is no proof that OA entails a cost in terms of reduced YP. WUE for yield is often equated in a simplistic manner with DR. The large accumulation of knowledge on crop WUE as derived from research on carbon isotope discrimination allows some conclusions on the relations between WUE on the one hand, and DR and YP on the other, to be made. Briefly, apparent genotypic variations in WUE are normally expressed mainly due to variations in water use (WU; the denominator). Reduced WU, which is reflected in higher WUE, is generally achieved by plant traits and environmental responses that reduce YP. Improved WUE on the basis of reduced WU is expressed in improved yield under water-limited conditions only when there is need to balance crop water use against a limited and known soil moisture reserve. However, under most dryland situations where crops depend on unpredictable seasonal rainfall, the maximisation of soil moisture use is a crucial component of drought resistance (avoidance), which is generally expressed in lower WUE. It is concluded that the effect of a single ‘drought adaptive’ gene on crop performance in water-limited environments can be assessed only when the whole system is considered in terms of YP, DR, and WUE.

Journal

Crop and Pasture ScienceCSIRO Publishing

Published: Nov 29, 2005

Keywords: plant breeding, osmotic adjustment, drought tolerance, phenology.

References