Use of physiological traits in tree breeding for improved yield in drought-prone environments. The case of Eucalyptus globulus

P Pita,I Cañas,F Soria,F Ruiz,G Toval

doi:10.5424/srf/2005143-00931

P Pita, I Cañas + Show 3 more

Open Access

https://doi.org/10.5424/srf/2005143-00931

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Abstract

Selecting for improved growth in drought-prone environments may lead to a trade-off between traits related to both growth and drought resistance. This paper provides a review of the use of physiological traits in breeding for yield improvement in water-limited environments. Plant responses to water stress can be grouped into strategies, which are species-specific. Once a species drought resistance strategy is known, several physiological traits can be selected to be used in the species breeding program. Despite there are multiple physiological traits involved in plant responses to drought, only a few of them have been actually used to improve both growth and drought resistance. This review highlights the relevance of stomatal conductance and water-use efficiency as well as hydraulic traits in breeding for improved growth in drought-prone environments. It is illustrated with unpublished results obtained in several research programmes that share a common objective: improving Eucalyptus globulus growth and survival in south-western Spain throughout early selection based on morpho-physiological traits.

Highlights

According to Pereira (1995) we may define stress as any environmental factor that makes growth rate lower than maximum
The following will review major results of some physiological traits commonly proposed to be used in breeding for improved drought resistance, such as stomatal conductance, water use efficiency and hydraulic traits
Results from several studies carried out in E. globulus show that the species must be considered as a dehydration avoider, because higher survival and yield are achieved through lower water use efficiency and embolism tolerance

Summary

Introduction

According to Pereira (1995) we may define stress as any environmental factor that makes growth rate lower than maximum. Water spenders may as well tolerate the loss of relatively high amounts of xylem hydraulic conductivity by embolism. The following will review major results of some physiological traits commonly proposed to be used in breeding for improved drought resistance, such as stomatal conductance, water use efficiency and hydraulic traits.

Results

Conclusion