Breeding of Salix
|The potential for Salix as energy crop was first noticed during the 1970s and research on Salix breeding in order to improve biomass yield and resistance to pests and diseases was initiated at SLU in Uppsala. An extensive collections of Salix from Sweden, Europe and North America was established at SLU during the late 1970s. A breeding program utilizing this material was run in the following years, and about 100 subpopulations with increased homozygosity were developed through recurrent brother-sister mating. Commercial breeding of Salix started in 1987 by Svalöf Weibull AB, a program that progressed rapidly and led to the release of the first dedicated biomass varieties in the early 1990s. Willow breeding in Sweden has continued under Lantmännen Agroenergi AB. At present, approximately ten bred varieties are used in Salix plantations.
A way forward for more efficient breeding of Salix is the use of a method known as MAS or marker assisted selection. MAS is the selection of breeding material by the use of easily detectable genetic markers linked to QTL underling phenotypic traits. MAS is particularly useful for traits that are difficult to measure, exhibit low heritability, and/or are expressed late in development, such as productivity, disease resistance, drought and heat tolerance. To develop efficient MAS in willow, we are identifying QTL and genes responsible for selected phenotypic traits. The single nucleotide polymorphism (SNP) that we identify in the candidate genes can be used as a selection tool in MAS.