Abstract

Quantitative trait loci (QTL) for growth traits and water use efficiency (measured as ?13C) have been identified in two water regimes (normal and drought treated) and for a tolerance treatment index. A tetraploid hybrid F2 population originating from a cross between a Salix dasyclados-clone (SW901290) and a S. viminalis-clone ('Jorunn') was used in the study. The growth response of each individual including both above and below ground dry-matter production (i. e. shoot length, shoot diameter, above-ground and root dry weight, internode length, root dry weight/total dry weight, relative growth rate and leaf nitrogen content) was analyzed in a replicated block experiment with two water treatments. A composite interval mapping approach was used to estimate number of QTL, the magnitude of the QTL and their position on genetic linkage maps. QTL specific for each treatment and for the treatment index were found but also QTL common across the treatments and the treatment index were detected. Each QTL explained from 8 to 29 % of the phenotypic variation depending on f trait and treatment. Clusters of QTL for different traits were mapped close to each other at several linkage groups indicating either a common genetic base or tightly- linked QTL. Common QTL identified between treatments and treatment index in the complex trait dry-weight can be useful tools in the breeding and selection for drought stress tolerance in Salix

Keywords

breeding; QTL; drought tolerance; growth; Salix viminalis; Salix dasyclados

Published in

TAG Theoretical and Applied Genetics
2005, volume: 110, number: 3, pages: 537-549
Publisher: SPRINGER

Authors' information