Clonal variability for water use efficiency and carbon isotope discrimination ( 13C) in selected clones of a few Eucalyptus species

Abstract

Eucalyptus, one of the fast growing tree species extracts water from a depth of up to 15 meters. As a prolific producer of biomass/ wood, eucalyptus has been included as commercially important tree species under various afforestation programmes in many parts of the world although there is a controversy regarding the reported reduction of stream flow associated with this species. Therefore in this scenario, it is necessary to make an attempt to use selections with reduced water use or to select and develop high water use efficient clones to cultivate under water limited environments. The major objective was to assess the eucalyptus clones for variability in WUE and to determine the relationship between WUE and carbon isotope discrimination ( 13C) for large scale screening and selection for high WUE. It is concluded that clonal variability for WUE does exist in Eucalyptus and therefore, this variability can be exploited for eucalyptus tree improvement. Further, the negative relationship found between WUE and 13C paves the way for screening large numbers of clones for WUE in the identification of superior clones with high WUE.